;************************************************************** ;* ;* C P / M version 2 . 2 ;* ;* Reconstructed from memory image on February 27, 1981 ;* ;* by Clark A. Calkins ;* ;************************************************************** ; ; Set memory limit here. This is the amount of contigeous ; ram starting from 0000. CP/M will reside at the end of this space. ; MEM EQU 62 ;for a 62k system (TS802 TEST - WORKS OK). ; IOBYTE EQU 3 ;i/o definition byte. TDRIVE EQU 4 ;current drive name and user number. ENTRY EQU 5 ;entry point for the cp/m bdos. TFCB EQU 5CH ;default file control block. TBUFF EQU 80H ;i/o buffer and command line storage. TBASE EQU 100H ;transiant program storage area. ; ; Set control character equates. ; CNTRLC EQU 3 ;control-c CNTRLE EQU 05H ;control-e BS EQU 08H ;backspace TAB EQU 09H ;tab LF EQU 0AH ;line feed FF EQU 0CH ;form feed CR EQU 0DH ;carriage return CNTRLP EQU 10H ;control-p CNTRLR EQU 12H ;control-r CNTRLS EQU 13H ;control-s CNTRLU EQU 15H ;control-u CNTRLX EQU 18H ;control-x CNTRLZ EQU 1AH ;control-z (end-of-file mark) DEL EQU 7FH ;rubout ; ; Set origin for CP/M ; ORG (MEM-7)*1024 ; CBASE: JP COMMAND ;execute command processor (ccp). JP CLEARBUF ;entry to empty input buffer before starting ccp. ; ; Standard cp/m ccp input buffer. Format is (max length), ; (actual length), (char #1), (char #2), (char #3), etc. ; INBUFF: DEFB 127 ;length of input buffer. DEFB 0 ;current length of contents. DEFB 'Copyright' DEFB ' 1979 (c) by Digital Research ' DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 INPOINT:DEFW INBUFF+2 ;input line pointer NAMEPNT:DEFW 0 ;input line pointer used for error message. Points to ; ;start of name in error. ; ; Routine to print (A) on the console. All registers used. ; PRINT: LD E,A ;setup bdos call. LD C,2 JP ENTRY ; ; Routine to print (A) on the console and to save (BC). ; PRINTB: PUSH BC CALL PRINT POP BC RET ; ; Routine to send a carriage return, line feed combination ; to the console. ; CRLF: LD A,CR CALL PRINTB LD A,LF JP PRINTB ; ; Routine to send one space to the console and save (BC). ; SPACE: LD A,' ' JP PRINTB ; ; Routine to print character string pointed to be (BC) on the ; console. It must terminate with a null byte. ; PLINE: PUSH BC CALL CRLF POP HL PLINE2: LD A,(HL) OR A RET Z INC HL PUSH HL CALL PRINT POP HL JP PLINE2 ; ; Routine to reset the disk system. ; RESDSK: LD C,13 JP ENTRY ; ; Routine to select disk (A). ; DSKSEL: LD E,A LD C,14 JP ENTRY ; ; Routine to call bdos and save the return code. The zero ; flag is set on a return of 0ffh. ; ENTRY1: CALL ENTRY LD (RTNCODE),A ;save return code. INC A ;set zero if 0ffh returned. RET ; ; Routine to open a file. (DE) must point to the FCB. ; OPEN: LD C,15 JP ENTRY1 ; ; Routine to open file at (FCB). ; OPENFCB:XOR A ;clear the record number byte at fcb+32 LD (FCB+32),A LD DE,FCB JP OPEN ; ; Routine to close a file. (DE) points to FCB. ; CLOSE: LD C,16 JP ENTRY1 ; ; Routine to search for the first file with ambigueous name ; (DE). ; SRCHFST:LD C,17 JP ENTRY1 ; ; Search for the next ambigeous file name. ; SRCHNXT:LD C,18 JP ENTRY1 ; ; Search for file at (FCB). ; SRCHFCB:LD DE,FCB JP SRCHFST ; ; Routine to delete a file pointed to by (DE). ; DELETE: LD C,19 JP ENTRY ; ; Routine to call the bdos and set the zero flag if a zero ; status is returned. ; ENTRY2: CALL ENTRY OR A ;set zero flag if appropriate. RET ; ; Routine to read the next record from a sequential file. ; (DE) points to the FCB. ; RDREC: LD C,20 JP ENTRY2 ; ; Routine to read file at (FCB). ; READFCB:LD DE,FCB JP RDREC ; ; Routine to write the next record of a sequential file. ; (DE) points to the FCB. ; WRTREC: LD C,21 JP ENTRY2 ; ; Routine to create the file pointed to by (DE). ; CREATE: LD C,22 JP ENTRY1 ; ; Routine to rename the file pointed to by (DE). Note that ; the new name starts at (DE+16). ; RENAM: LD C,23 JP ENTRY ; ; Get the current user code. ; GETUSR: LD E,0FFH ; ; Routne to get or set the current user code. ; If (E) is FF then this is a GET, else it is a SET. ; GETSETUC: LD C,32 JP ENTRY ; ; Routine to set the current drive byte at (TDRIVE). ; SETCDRV:CALL GETUSR ;get user number ADD A,A ;and shift into the upper 4 bits. ADD A,A ADD A,A ADD A,A LD HL,CDRIVE ;now add in the current drive number. OR (HL) LD (TDRIVE),A ;and save. RET ; ; Move currently active drive down to (TDRIVE). ; MOVECD: LD A,(CDRIVE) LD (TDRIVE),A RET ; ; Routine to convert (A) into upper case ascii. Only letters ; are affected. ; UPPER: CP 'a' ;check for letters in the range of 'a' to 'z'. RET C CP '{' RET NC AND 5FH ;convert it if found. RET ; ; Routine to get a line of input. We must check to see if the ; user is in (BATCH) mode. If so, then read the input from file ; ($$$.SUB). At the end, reset to console input. ; GETINP: LD A,(BATCH) ;if =0, then use console input. OR A JP Z,GETINP1 ; ; Use the submit file ($$$.sub) which is prepared by a ; SUBMIT run. It must be on drive (A) and it will be deleted ; if and error occures (like eof). ; LD A,(CDRIVE) ;select drive 0 if need be. OR A LD A,0 ;always use drive A for submit. CALL NZ,DSKSEL ;select it if required. LD DE,BATCHFCB CALL OPEN ;look for it. JP Z,GETINP1 ;if not there, use normal input. LD A,(BATCHFCB+15) ;get last record number+1. DEC A LD (BATCHFCB+32),A LD DE,BATCHFCB CALL RDREC ;read last record. JP NZ,GETINP1 ;quit on end of file. ; ; Move this record into input buffer. ; LD DE,INBUFF+1 LD HL,TBUFF ;data was read into buffer here. LD B,128 ;all 128 characters may be used. CALL HL2DE ;(HL) to (DE), (B) bytes. LD HL,BATCHFCB+14 LD (HL),0 ;zero out the 's2' byte. INC HL ;and decrement the record count. DEC (HL) LD DE,BATCHFCB ;close the batch file now. CALL CLOSE JP Z,GETINP1 ;quit on an error. LD A,(CDRIVE) ;re-select previous drive if need be. OR A CALL NZ,DSKSEL ;don't do needless selects. ; ; Print line just read on console. ; LD HL,INBUFF+2 CALL PLINE2 CALL CHKCON ;check console, quit on a key. JP Z,GETINP2 ;jump if no key is pressed. ; ; Terminate the submit job on any keyboard input. Delete this ; file such that it is not re-started and jump to normal keyboard ; input section. ; CALL DELBATCH ;delete the batch file. JP CMMND1 ;and restart command input. ; ; Get here for normal keyboard input. Delete the submit file ; incase there was one. ; GETINP1:CALL DELBATCH ;delete file ($$$.sub). CALL SETCDRV ;reset active disk. LD C,10 ;get line from console device. LD DE,INBUFF CALL ENTRY CALL MOVECD ;reset current drive (again). ; ; Convert input line to upper case. ; GETINP2:LD HL,INBUFF+1 LD B,(HL) ;(B)=character counter. GETINP3:INC HL LD A,B ;end of the line? OR A JP Z,GETINP4 LD A,(HL) ;convert to upper case. CALL UPPER LD (HL),A DEC B ;adjust character count. JP GETINP3 GETINP4:LD (HL),A ;add trailing null. LD HL,INBUFF+2 LD (INPOINT),HL ;reset input line pointer. RET ; ; Routine to check the console for a key pressed. The zero ; flag is set is none, else the character is returned in (A). ; CHKCON: LD C,11 ;check console. CALL ENTRY OR A RET Z ;return if nothing. LD C,1 ;else get character. CALL ENTRY OR A ;clear zero flag and return. RET ; ; Routine to get the currently active drive number. ; GETDSK: LD C,25 JP ENTRY ; ; Set the stabdard dma address. ; STDDMA: LD DE,TBUFF ; ; Routine to set the dma address to (DE). ; DMASET: LD C,26 JP ENTRY ; ; Delete the batch file created by SUBMIT. ; DELBATCH: LD HL,BATCH ;is batch active? LD A,(HL) OR A RET Z LD (HL),0 ;yes, de-activate it. XOR A CALL DSKSEL ;select drive 0 for sure. LD DE,BATCHFCB ;and delete this file. CALL DELETE LD A,(CDRIVE) ;reset current drive. JP DSKSEL ; ; Check to two strings at (PATTRN1) and (PATTRN2). They must be ; the same or we halt.... ; VERIFY: LD DE,PATTRN1 ;these are the serial number bytes. LD HL,PATTRN2 ;ditto, but how could they be different? LD B,6 ;6 bytes each. VERIFY1:LD A,(DE) CP (HL) JP NZ,HALT ;jump to halt routine. INC DE INC HL DEC B JP NZ,VERIFY1 RET ; ; Print back file name with a '?' to indicate a syntax error. ; SYNERR: CALL CRLF ;end current line. LD HL,(NAMEPNT) ;this points to name in error. SYNERR1:LD A,(HL) ;print it until a space or null is found. CP ' ' JP Z,SYNERR2 OR A JP Z,SYNERR2 PUSH HL CALL PRINT POP HL INC HL JP SYNERR1 SYNERR2:LD A,'?' ;add trailing '?'. CALL PRINT CALL CRLF CALL DELBATCH ;delete any batch file. JP CMMND1 ;and restart from console input. ; ; Check character at (DE) for legal command input. Note that the ; zero flag is set if the character is a delimiter. ; CHECK: LD A,(DE) OR A RET Z CP ' ' ;control characters are not legal here. JP C,SYNERR RET Z ;check for valid delimiter. CP '=' RET Z CP '_' RET Z CP '.' RET Z CP ':' RET Z CP ";" RET Z CP '<' RET Z CP '>' RET Z RET ; ; Get the next non-blank character from (DE). ; NONBLANK: LD A,(DE) OR A ;string ends with a null. RET Z CP ' ' RET NZ INC DE JP NONBLANK ; ; Add (HL)=(HL)+(A) ; ADDHL: ADD A,L LD L,A RET NC ;take care of any carry. INC H RET ; ; Convert the first name in (FCB). ; CONVFST:LD A,0 ; ; Format a file name (convert * to '?', etc.). On return, ; (A)=0 is an unambigeous name was specified. Enter with (A) equal to ; the position within the fcb for the name (either 0 or 16). ; CONVERT:LD HL,FCB CALL ADDHL PUSH HL PUSH HL XOR A LD (CHGDRV),A ;initialize drive change flag. LD HL,(INPOINT) ;set (HL) as pointer into input line. EX DE,HL CALL NONBLANK ;get next non-blank character. EX DE,HL LD (NAMEPNT),HL ;save pointer here for any error message. EX DE,HL POP HL LD A,(DE) ;get first character. OR A JP Z,CONVRT1 SBC A,'A'-1 ;might be a drive name, convert to binary. LD B,A ;and save. INC DE ;check next character for a ':'. LD A,(DE) CP ':' JP Z,CONVRT2 DEC DE ;nope, move pointer back to the start of the line. CONVRT1:LD A,(CDRIVE) LD (HL),A JP CONVRT3 CONVRT2:LD A,B LD (CHGDRV),A ;set change in drives flag. LD (HL),B INC DE ; ; Convert the basic file name. ; CONVRT3:LD B,08H CONVRT4:CALL CHECK JP Z,CONVRT8 INC HL CP '*' ;note that an '*' will fill the remaining JP NZ,CONVRT5 ;field with '?'. LD (HL),'?' JP CONVRT6 CONVRT5:LD (HL),A INC DE CONVRT6:DEC B JP NZ,CONVRT4 CONVRT7:CALL CHECK ;get next delimiter. JP Z,GETEXT INC DE JP CONVRT7 CONVRT8:INC HL ;blank fill the file name. LD (HL),' ' DEC B JP NZ,CONVRT8 ; ; Get the extension and convert it. ; GETEXT: LD B,03H CP '.' JP NZ,GETEXT5 INC DE GETEXT1:CALL CHECK JP Z,GETEXT5 INC HL CP '*' JP NZ,GETEXT2 LD (HL),'?' JP GETEXT3 GETEXT2:LD (HL),A INC DE GETEXT3:DEC B JP NZ,GETEXT1 GETEXT4:CALL CHECK JP Z,GETEXT6 INC DE JP GETEXT4 GETEXT5:INC HL LD (HL),' ' DEC B JP NZ,GETEXT5 GETEXT6:LD B,3 GETEXT7:INC HL LD (HL),0 DEC B JP NZ,GETEXT7 EX DE,HL LD (INPOINT),HL ;save input line pointer. POP HL ; ; Check to see if this is an ambigeous file name specification. ; Set the (A) register to non zero if it is. ; LD BC,11 ;set name length. GETEXT8:INC HL LD A,(HL) CP '?' ;any question marks? JP NZ,GETEXT9 INC B ;count them. GETEXT9:DEC C JP NZ,GETEXT8 LD A,B OR A RET ; ; CP/M command table. Note commands can be either 3 or 4 characters long. ; NUMCMDS EQU 6 ;number of commands CMDTBL: DEFB 'DIR ' DEFB 'ERA ' DEFB 'TYPE' DEFB 'SAVE' DEFB 'REN ' DEFB 'USER' ; ; The following six bytes must agree with those at (PATTRN2) ; or cp/m will HALT. Why? ; PATTRN1:DEFB 0,22,0,0,0,0 ;(* serial number bytes *). ; ; Search the command table for a match with what has just ; been entered. If a match is found, then we jump to the ; proper section. Else jump to (UNKNOWN). ; On return, the (C) register is set to the command number ; that matched (or NUMCMDS+1 if no match). ; SEARCH: LD HL,CMDTBL LD C,0 SEARCH1:LD A,C CP NUMCMDS ;this commands exists. RET NC LD DE,FCB+1 ;check this one. LD B,4 ;max command length. SEARCH2:LD A,(DE) CP (HL) JP NZ,SEARCH3 ;not a match. INC DE INC HL DEC B JP NZ,SEARCH2 LD A,(DE) ;allow a 3 character command to match. CP ' ' JP NZ,SEARCH4 LD A,C ;set return register for this command. RET SEARCH3:INC HL DEC B JP NZ,SEARCH3 SEARCH4:INC C JP SEARCH1 ; ; Set the input buffer to empty and then start the command ; processor (ccp). ; CLEARBUF: XOR A LD (INBUFF+1),A ;second byte is actual length. ; ;************************************************************** ;* ;* ;* C C P - C o n s o l e C o m m a n d P r o c e s s o r ;* ;************************************************************** ;* COMMAND:LD SP,CCPSTACK ;setup stack area. PUSH BC ;note that (C) should be equal to: LD A,C ;(uuuudddd) where 'uuuu' is the user number RRA ;and 'dddd' is the drive number. RRA RRA RRA AND 0FH ;isolate the user number. LD E,A CALL GETSETUC ;and set it. CALL RESDSK ;reset the disk system. LD (BATCH),A ;clear batch mode flag. POP BC LD A,C AND 0FH ;isolate the drive number. LD (CDRIVE),A ;and save. CALL DSKSEL ;...and select. LD A,(INBUFF+1) OR A ;anything in input buffer already? JP NZ,CMMND2 ;yes, we just process it. ; ; Entry point to get a command line from the console. ; CMMND1: LD SP,CCPSTACK ;set stack straight. CALL CRLF ;start a new line on the screen. CALL GETDSK ;get current drive. ADD A,'a' CALL PRINT ;print current drive. LD A,'>' CALL PRINT ;and add prompt. CALL GETINP ;get line from user. ; ; Process command line here. ; CMMND2: LD DE,TBUFF CALL DMASET ;set standard dma address. CALL GETDSK LD (CDRIVE),A ;set current drive. CALL CONVFST ;convert name typed in. CALL NZ,SYNERR ;wild cards are not allowed. LD A,(CHGDRV) ;if a change in drives was indicated, OR A ;then treat this as an unknown command JP NZ,UNKNOWN ;which gets executed. CALL SEARCH ;else search command table for a match. ; ; Note that an unknown command returns ; with (A) pointing to the last address ; in our table which is (UNKNOWN). ; LD HL,CMDADR ;now, look thru our address table for command (A). LD E,A ;set (DE) to command number. LD D,0 ADD HL,DE ADD HL,DE ;(HL)=(CMDADR)+2*(command number). LD A,(HL) ;now pick out this address. INC HL LD H,(HL) LD L,A JP (HL) ;now execute it. ; ; CP/M command address table. ; CMDADR: DEFW DIRECT,ERASE,TYPE,SAVE DEFW RENAME,USER,UNKNOWN ; ; Halt the system. Reason for this is unknown at present. ; HALT: LD HL,76F3H ;'DI HLT' instructions. LD (CBASE),HL LD HL,CBASE JP (HL) ; ; Read error while TYPEing a file. ; RDERROR:LD BC,RDERR JP PLINE RDERR: DEFB 'Read error',0 ; ; Required file was not located. ; NONE: LD BC,NOFILE JP PLINE NOFILE: DEFB 'No file',0 ; ; Decode a command of the form 'A>filename number{ filename}. ; Note that a drive specifier is not allowed on the first file ; name. On return, the number is in register (A). Any error ; causes 'filename?' to be printed and the command is aborted. ; DECODE: CALL CONVFST ;convert filename. LD A,(CHGDRV) ;do not allow a drive to be specified. OR A JP NZ,SYNERR LD HL,FCB+1 ;convert number now. LD BC,11 ;(B)=sum register, (C)=max digit count. DECODE1:LD A,(HL) CP ' ' ;a space terminates the numeral. JP Z,DECODE3 INC HL SUB '0' ;make binary from ascii. CP 10 ;legal digit? JP NC,SYNERR LD D,A ;yes, save it in (D). LD A,B ;compute (B)=(B)*10 and check for overflow. AND 0E0H JP NZ,SYNERR LD A,B RLCA RLCA RLCA ;(A)=(B)*8 ADD A,B ;.......*9 JP C,SYNERR ADD A,B ;.......*10 JP C,SYNERR ADD A,D ;add in new digit now. DECODE2:JP C,SYNERR LD B,A ;and save result. DEC C ;only look at 11 digits. JP NZ,DECODE1 RET DECODE3:LD A,(HL) ;spaces must follow (why?). CP ' ' JP NZ,SYNERR INC HL DECODE4:DEC C JP NZ,DECODE3 LD A,B ;set (A)=the numeric value entered. RET ; ; Move 3 bytes from (HL) to (DE). Note that there is only ; one reference to this at (A2D5h). ; MOVE3: LD B,3 ; ; Move (B) bytes from (HL) to (DE). ; HL2DE: LD A,(HL) LD (DE),A INC HL INC DE DEC B JP NZ,HL2DE RET ; ; Compute (HL)=(TBUFF)+(A)+(C) and get the byte that's here. ; EXTRACT:LD HL,TBUFF ADD A,C CALL ADDHL LD A,(HL) RET ; ; Check drive specified. If it means a change, then the new ; drive will be selected. In any case, the drive byte of the ; fcb will be set to null (means use current drive). ; DSELECT:XOR A ;null out first byte of fcb. LD (FCB),A LD A,(CHGDRV) ;a drive change indicated? OR A RET Z DEC A ;yes, is it the same as the current drive? LD HL,CDRIVE CP (HL) RET Z JP DSKSEL ;no. Select it then. ; ; Check the drive selection and reset it to the previous ; drive if it was changed for the preceeding command. ; RESETDR:LD A,(CHGDRV) ;drive change indicated? OR A RET Z DEC A ;yes, was it a different drive? LD HL,CDRIVE CP (HL) RET Z LD A,(CDRIVE) ;yes, re-select our old drive. JP DSKSEL ; ;************************************************************** ;* ;* D I R E C T O R Y C O M M A N D ;* ;************************************************************** ; DIRECT: CALL CONVFST ;convert file name. CALL DSELECT ;select indicated drive. LD HL,FCB+1 ;was any file indicated? LD A,(HL) CP ' ' JP NZ,DIRECT2 LD B,11 ;no. Fill field with '?' - same as *.*. DIRECT1:LD (HL),'?' INC HL DEC B JP NZ,DIRECT1 DIRECT2:LD E,0 ;set initial cursor position. PUSH DE CALL SRCHFCB ;get first file name. CALL Z,NONE ;none found at all? DIRECT3:JP Z,DIRECT9 ;terminate if no more names. LD A,(RTNCODE) ;get file's position in segment (0-3). RRCA RRCA RRCA AND 60H ;(A)=position*32 LD C,A LD A,10 CALL EXTRACT ;extract the tenth entry in fcb. RLA ;check system file status bit. JP C,DIRECT8 ;we don't list them. POP DE LD A,E ;bump name count. INC E PUSH DE AND 03H ;at end of line? PUSH AF JP NZ,DIRECT4 CALL CRLF ;yes, end this line and start another. PUSH BC CALL GETDSK ;start line with ('A:'). POP BC ADD A,'A' CALL PRINTB LD A,':' CALL PRINTB JP DIRECT5 DIRECT4:CALL SPACE ;add seperator between file names. LD A,':' CALL PRINTB DIRECT5:CALL SPACE LD B,1 ;'extract' each file name character at a time. DIRECT6:LD A,B CALL EXTRACT AND 7FH ;strip bit 7 (status bit). CP ' ' ;are we at the end of the name? JP NZ,DRECT65 POP AF ;yes, don't print spaces at the end of a line. PUSH AF CP 3 JP NZ,DRECT63 LD A,9 ;first check for no extension. CALL EXTRACT AND 7FH CP ' ' JP Z,DIRECT7 ;don't print spaces. DRECT63:LD A,' ' ;else print them. DRECT65:CALL PRINTB INC B ;bump to next character psoition. LD A,B CP 12 ;end of the name? JP NC,DIRECT7 CP 9 ;nope, starting extension? JP NZ,DIRECT6 CALL SPACE ;yes, add seperating space. JP DIRECT6 DIRECT7:POP AF ;get the next file name. DIRECT8:CALL CHKCON ;first check console, quit on anything. JP NZ,DIRECT9 CALL SRCHNXT ;get next name. JP DIRECT3 ;and continue with our list. DIRECT9:POP DE ;restore the stack and return to command level. JP GETBACK ; ;************************************************************** ;* ;* E R A S E C O M M A N D ;* ;************************************************************** ; ERASE: CALL CONVFST ;convert file name. CP 11 ;was '*.*' entered? JP NZ,ERASE1 LD BC,YESNO ;yes, ask for confirmation. CALL PLINE CALL GETINP LD HL,INBUFF+1 DEC (HL) ;must be exactly 'y'. JP NZ,CMMND1 INC HL LD A,(HL) CP 'Y' JP NZ,CMMND1 INC HL LD (INPOINT),HL ;save input line pointer. ERASE1: CALL DSELECT ;select desired disk. LD DE,FCB CALL DELETE ;delete the file. INC A CALL Z,NONE ;not there? JP GETBACK ;return to command level now. YESNO: DEFB 'All (y/n)?',0 ; ;************************************************************** ;* ;* T Y P E C O M M A N D ;* ;************************************************************** ; TYPE: CALL CONVFST ;convert file name. JP NZ,SYNERR ;wild cards not allowed. CALL DSELECT ;select indicated drive. CALL OPENFCB ;open the file. JP Z,TYPE5 ;not there? CALL CRLF ;ok, start a new line on the screen. LD HL,NBYTES ;initialize byte counter. LD (HL),0FFH ;set to read first sector. TYPE1: LD HL,NBYTES TYPE2: LD A,(HL) ;have we written the entire sector? CP 128 JP C,TYPE3 PUSH HL ;yes, read in the next one. CALL READFCB POP HL JP NZ,TYPE4 ;end or error? XOR A ;ok, clear byte counter. LD (HL),A TYPE3: INC (HL) ;count this byte. LD HL,TBUFF ;and get the (A)th one from the buffer (TBUFF). CALL ADDHL LD A,(HL) CP CNTRLZ ;end of file mark? JP Z,GETBACK CALL PRINT ;no, print it. CALL CHKCON ;check console, quit if anything ready. JP NZ,GETBACK JP TYPE1 ; ; Get here on an end of file or read error. ; TYPE4: DEC A ;read error? JP Z,GETBACK CALL RDERROR ;yes, print message. TYPE5: CALL RESETDR ;and reset proper drive JP SYNERR ;now print file name with problem. ; ;************************************************************** ;* ;* S A V E C O M M A N D ;* ;************************************************************** ; SAVE: CALL DECODE ;get numeric number that follows SAVE. PUSH AF ;save number of pages to write. CALL CONVFST ;convert file name. JP NZ,SYNERR ;wild cards not allowed. CALL DSELECT ;select specified drive. LD DE,FCB ;now delete this file. PUSH DE CALL DELETE POP DE CALL CREATE ;and create it again. JP Z,SAVE3 ;can't create? XOR A ;clear record number byte. LD (FCB+32),A POP AF ;convert pages to sectors. LD L,A LD H,0 ADD HL,HL ;(HL)=number of sectors to write. LD DE,TBASE ;and we start from here. SAVE1: LD A,H ;done yet? OR L JP Z,SAVE2 DEC HL ;nope, count this and compute the start PUSH HL ;of the next 128 byte sector. LD HL,128 ADD HL,DE PUSH HL ;save it and set the transfer address. CALL DMASET LD DE,FCB ;write out this sector now. CALL WRTREC POP DE ;reset (DE) to the start of the last sector. POP HL ;restore sector count. JP NZ,SAVE3 ;write error? JP SAVE1 ; ; Get here after writing all of the file. ; SAVE2: LD DE,FCB ;now close the file. CALL CLOSE INC A ;did it close ok? JP NZ,SAVE4 ; ; Print out error message (no space). ; SAVE3: LD BC,NOSPACE CALL PLINE SAVE4: CALL STDDMA ;reset the standard dma address. JP GETBACK NOSPACE:DEFB 'No space',0 ; ;************************************************************** ;* ;* R E N A M E C O M M A N D ;* ;************************************************************** ; RENAME: CALL CONVFST ;convert first file name. JP NZ,SYNERR ;wild cards not allowed. LD A,(CHGDRV) ;remember any change in drives specified. PUSH AF CALL DSELECT ;and select this drive. CALL SRCHFCB ;is this file present? JP NZ,RENAME6 ;yes, print error message. LD HL,FCB ;yes, move this name into second slot. LD DE,FCB+16 LD B,16 CALL HL2DE LD HL,(INPOINT) ;get input pointer. EX DE,HL CALL NONBLANK ;get next non blank character. CP '=' ;only allow an '=' or '_' seperator. JP Z,RENAME1 CP '_' JP NZ,RENAME5 RENAME1:EX DE,HL INC HL ;ok, skip seperator. LD (INPOINT),HL ;save input line pointer. CALL CONVFST ;convert this second file name now. JP NZ,RENAME5 ;again, no wild cards. POP AF ;if a drive was specified, then it LD B,A ;must be the same as before. LD HL,CHGDRV LD A,(HL) OR A JP Z,RENAME2 CP B LD (HL),B JP NZ,RENAME5 ;they were different, error. RENAME2:LD (HL),B ; reset as per the first file specification. XOR A LD (FCB),A ;clear the drive byte of the fcb. RENAME3:CALL SRCHFCB ;and go look for second file. JP Z,RENAME4 ;doesn't exist? LD DE,FCB CALL RENAM ;ok, rename the file. JP GETBACK ; ; Process rename errors here. ; RENAME4:CALL NONE ;file not there. JP GETBACK RENAME5:CALL RESETDR ;bad command format. JP SYNERR RENAME6:LD BC,EXISTS ;destination file already exists. CALL PLINE JP GETBACK EXISTS: DEFB 'File exists',0 ; ;************************************************************** ;* ;* U S E R C O M M A N D ;* ;************************************************************** ; USER: CALL DECODE ;get numeric value following command. CP 16 ;legal user number? JP NC,SYNERR LD E,A ;yes but is there anything else? LD A,(FCB+1) CP ' ' JP Z,SYNERR ;yes, that is not allowed. CALL GETSETUC ;ok, set user code. JP GETBACK1 ; ;************************************************************** ;* ;* T R A N S I A N T P R O G R A M C O M M A N D ;* ;************************************************************** ; UNKNOWN:CALL VERIFY ;check for valid system (why?). LD A,(FCB+1) ;anything to execute? CP ' ' JP NZ,UNKWN1 LD A,(CHGDRV) ;nope, only a drive change? OR A JP Z,GETBACK1 ;neither??? DEC A LD (CDRIVE),A ;ok, store new drive. CALL MOVECD ;set (TDRIVE) also. CALL DSKSEL ;and select this drive. JP GETBACK1 ;then return. ; ; Here a file name was typed. Prepare to execute it. ; UNKWN1: LD DE,FCB+9 ;an extension specified? LD A,(DE) CP ' ' JP NZ,SYNERR ;yes, not allowed. UNKWN2: PUSH DE CALL DSELECT ;select specified drive. POP DE LD HL,COMFILE ;set the extension to 'COM'. CALL MOVE3 CALL OPENFCB ;and open this file. JP Z,UNKWN9 ;not present? ; ; Load in the program. ; LD HL,TBASE ;store the program starting here. UNKWN3: PUSH HL EX DE,HL CALL DMASET ;set transfer address. LD DE,FCB ;and read the next record. CALL RDREC JP NZ,UNKWN4 ;end of file or read error? POP HL ;nope, bump pointer for next sector. LD DE,128 ADD HL,DE LD DE,CBASE ;enough room for the whole file? LD A,L SUB E LD A,H SBC A,D JP NC,UNKWN0 ;no, it can't fit. JP UNKWN3 ; ; Get here after finished reading. ; UNKWN4: POP HL DEC A ;normal end of file? JP NZ,UNKWN0 CALL RESETDR ;yes, reset previous drive. CALL CONVFST ;convert the first file name that follows LD HL,CHGDRV ;command name. PUSH HL LD A,(HL) ;set drive code in default fcb. LD (FCB),A LD A,16 ;put second name 16 bytes later. CALL CONVERT ;convert second file name. POP HL LD A,(HL) ;and set the drive for this second file. LD (FCB+16),A XOR A ;clear record byte in fcb. LD (FCB+32),A LD DE,TFCB ;move it into place at(005Ch). LD HL,FCB LD B,33 CALL HL2DE LD HL,INBUFF+2 ;now move the remainder of the input UNKWN5: LD A,(HL) ;line down to (0080h). Look for a non blank. OR A ;or a null. JP Z,UNKWN6 CP ' ' JP Z,UNKWN6 INC HL JP UNKWN5 ; ; Do the line move now. It ends in a null byte. ; UNKWN6: LD B,0 ;keep a character count. LD DE,TBUFF+1 ;data gets put here. UNKWN7: LD A,(HL) ;move it now. LD (DE),A OR A JP Z,UNKWN8 INC B INC HL INC DE JP UNKWN7 UNKWN8: LD A,B ;now store the character count. LD (TBUFF),A CALL CRLF ;clean up the screen. CALL STDDMA ;set standard transfer address. CALL SETCDRV ;reset current drive. CALL TBASE ;and execute the program. ; ; Transiant programs return here (or reboot). ; LD SP,BATCH ;set stack first off. CALL MOVECD ;move current drive into place (TDRIVE). CALL DSKSEL ;and reselect it. JP CMMND1 ;back to comand mode. ; ; Get here if some error occured. ; UNKWN9: CALL RESETDR ;inproper format. JP SYNERR UNKWN0: LD BC,BADLOAD ;read error or won't fit. CALL PLINE JP GETBACK BADLOAD:DEFB 'Bad load',0 COMFILE:DEFB 'COM' ;command file extension. ; ; Get here to return to command level. We will reset the ; previous active drive and then either return to command ; level directly or print error message and then return. ; GETBACK:CALL RESETDR ;reset previous drive. GETBACK1: CALL CONVFST ;convert first name in (FCB). LD A,(FCB+1) ;if this was just a drive change request, SUB ' ' ;make sure it was valid. LD HL,CHGDRV OR (HL) JP NZ,SYNERR JP CMMND1 ;ok, return to command level. ; ; ccp stack area. ; DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 CCPSTACK EQU $ ;end of ccp stack area. ; ; Batch (or SUBMIT) processing information storage. ; BATCH: DEFB 0 ;batch mode flag (0=not active). BATCHFCB: DEFB 0,'$$$ SUB',0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ; ; File control block setup by the CCP. ; FCB: DEFB 0,' ',0,0,0,0,0,' ',0,0,0,0,0 RTNCODE:DEFB 0 ;status returned from bdos call. CDRIVE: DEFB 0 ;currently active drive. CHGDRV: DEFB 0 ;change in drives flag (0=no change). NBYTES: DEFW 0 ;byte counter used by TYPE. ; ; Room for expansion? ; DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0 ; ; Note that the following six bytes must match those at ; (PATTRN1) or cp/m will HALT. Why? ; PATTRN2:DEFB 0,22,0,0,0,0 ;(* serial number bytes *). ; ;************************************************************** ;* ;* B D O S E N T R Y ;* ;************************************************************** ; FBASE: JP FBASE1 ; ; Bdos error table. ; BADSCTR:DEFW ERROR1 ;bad sector on read or write. BADSLCT:DEFW ERROR2 ;bad disk select. RODISK: DEFW ERROR3 ;disk is read only. ROFILE: DEFW ERROR4 ;file is read only. ; ; Entry into bdos. (DE) or (E) are the parameters passed. The ; function number desired is in register (C). ; FBASE1: EX DE,HL ;save the (DE) parameters. LD (PARAMS),HL EX DE,HL LD A,E ;and save register (E) in particular. LD (EPARAM),A LD HL,0 LD (STATUS),HL ;clear return status. ADD HL,SP LD (USRSTACK),HL ;save users stack pointer. LD SP,STKAREA ;and set our own. XOR A ;clear auto select storage space. LD (AUTOFLAG),A LD (AUTO),A LD HL,GOBACK ;set return address. PUSH HL LD A,C ;get function number. CP NFUNCTS ;valid function number? RET NC LD C,E ;keep single register function here. LD HL,FUNCTNS ;now look thru the function table. LD E,A LD D,0 ;(DE)=function number. ADD HL,DE ADD HL,DE ;(HL)=(start of table)+2*(function number). LD E,(HL) INC HL LD D,(HL) ;now (DE)=address for this function. LD HL,(PARAMS) ;retrieve parameters. EX DE,HL ;now (DE) has the original parameters. JP (HL) ;execute desired function. ; ; BDOS function jump table. ; NFUNCTS EQU 41 ;number of functions in followin table. ; FUNCTNS:DEFW WBOOT,GETCON,OUTCON,GETRDR,PUNCH,LIST,DIRCIO,GETIOB DEFW SETIOB,PRTSTR,RDBUFF,GETCSTS,GETVER,RSTDSK,SETDSK,OPENFIL DEFW CLOSEFIL,GETFST,GETNXT,DELFILE,READSEQ,WRTSEQ,FCREATE DEFW RENFILE,GETLOG,GETCRNT,PUTDMA,GETALOC,WRTPRTD,GETROV,SETATTR DEFW GETPARM,GETUSER,RDRANDOM,WTRANDOM,FILESIZE,SETRAN,LOGOFF,RTN DEFW RTN,WTSPECL ; ; Bdos error message section. ; ERROR1: LD HL,BADSEC ;bad sector message. CALL PRTERR ;print it and get a 1 char responce. CP CNTRLC ;re-boot request (control-c)? JP Z,0 ;yes. RET ;no, return to retry i/o function. ; ERROR2: LD HL,BADSEL ;bad drive selected. JP ERROR5 ; ERROR3: LD HL,DISKRO ;disk is read only. JP ERROR5 ; ERROR4: LD HL,FILERO ;file is read only. ; ERROR5: CALL PRTERR JP 0 ;always reboot on these errors. ; BDOSERR:DEFB 'Bdos Err On ' BDOSDRV:DEFB ' : $' BADSEC: DEFB 'Bad Sector$' BADSEL: DEFB 'Select$' FILERO: DEFB 'File ' DISKRO: DEFB 'R/O$' ; ; Print bdos error message. ; PRTERR: PUSH HL ;save second message pointer. CALL OUTCRLF ;send (cr)(lf). LD A,(ACTIVE) ;get active drive. ADD A,'A' ;make ascii. LD (BDOSDRV),A ;and put in message. LD BC,BDOSERR ;and print it. CALL PRTMESG POP BC ;print second message line now. CALL PRTMESG ; ; Get an input character. We will check our 1 character ; buffer first. This may be set by the console status routine. ; GETCHAR:LD HL,CHARBUF ;check character buffer. LD A,(HL) ;anything present already? LD (HL),0 ;...either case clear it. OR A RET NZ ;yes, use it. JP CONIN ;nope, go get a character responce. ; ; Input and echo a character. ; GETECHO:CALL GETCHAR ;input a character. CALL CHKCHAR ;carriage control? RET C ;no, a regular control char so don't echo. PUSH AF ;ok, save character now. LD C,A CALL OUTCON ;and echo it. POP AF ;get character and return. RET ; ; Check character in (A). Set the zero flag on a carriage ; control character and the carry flag on any other control ; character. ; CHKCHAR:CP CR ;check for carriage return, line feed, backspace, RET Z ;or a tab. CP LF RET Z CP TAB RET Z CP BS RET Z CP ' ' ;other control char? Set carry flag. RET ; ; Check the console during output. Halt on a control-s, then ; reboot on a control-c. If anything else is ready, clear the ; zero flag and return (the calling routine may want to do ; something). ; CKCONSOL: LD A,(CHARBUF) ;check buffer. OR A ;if anything, just return without checking. JP NZ,CKCON2 CALL CONST ;nothing in buffer. Check console. AND 01H ;look at bit 0. RET Z ;return if nothing. CALL CONIN ;ok, get it. CP CNTRLS ;if not control-s, return with zero cleared. JP NZ,CKCON1 CALL CONIN ;halt processing until another char CP CNTRLC ;is typed. Control-c? JP Z,0 ;yes, reboot now. XOR A ;no, just pretend nothing was ever ready. RET CKCON1: LD (CHARBUF),A ;save character in buffer for later processing. CKCON2: LD A,1 ;set (A) to non zero to mean something is ready. RET ; ; Output (C) to the screen. If the printer flip-flop flag ; is set, we will send character to printer also. The console ; will be checked in the process. ; OUTCHAR:LD A,(OUTFLAG) ;check output flag. OR A ;anything and we won't generate output. JP NZ,OUTCHR1 PUSH BC CALL CKCONSOL ;check console (we don't care whats there). POP BC PUSH BC CALL CONOUT ;output (C) to the screen. POP BC PUSH BC LD A,(PRTFLAG) ;check printer flip-flop flag. OR A CALL NZ,LIST ;print it also if non-zero. POP BC OUTCHR1:LD A,C ;update cursors position. LD HL,CURPOS CP DEL ;rubouts don't do anything here. RET Z INC (HL) ;bump line pointer. CP ' ' ;and return if a normal character. RET NC DEC (HL) ;restore and check for the start of the line. LD A,(HL) OR A RET Z ;ingnore control characters at the start of the line. LD A,C CP BS ;is it a backspace? JP NZ,OUTCHR2 DEC (HL) ;yes, backup pointer. RET OUTCHR2:CP LF ;is it a line feed? RET NZ ;ignore anything else. LD (HL),0 ;reset pointer to start of line. RET ; ; Output (A) to the screen. If it is a control character ; (other than carriage control), use ^x format. ; SHOWIT: LD A,C CALL CHKCHAR ;check character. JP NC,OUTCON ;not a control, use normal output. PUSH AF LD C,'^' ;for a control character, preceed it with '^'. CALL OUTCHAR POP AF OR '@' ;and then use the letter equivelant. LD C,A ; ; Function to output (C) to the console device and expand tabs ; if necessary. ; OUTCON: LD A,C CP TAB ;is it a tab? JP NZ,OUTCHAR ;use regular output. OUTCON1:LD C,' ' ;yes it is, use spaces instead. CALL OUTCHAR LD A,(CURPOS) ;go until the cursor is at a multiple of 8 AND 07H ;position. JP NZ,OUTCON1 RET ; ; Echo a backspace character. Erase the prevoius character ; on the screen. ; BACKUP: CALL BACKUP1 ;backup the screen 1 place. LD C,' ' ;then blank that character. CALL CONOUT BACKUP1:LD C,BS ;then back space once more. JP CONOUT ; ; Signal a deleted line. Print a '#' at the end and start ; over. ; NEWLINE:LD C,'#' CALL OUTCHAR ;print this. CALL OUTCRLF ;start new line. NEWLN1: LD A,(CURPOS) ;move the cursor to the starting position. LD HL,STARTING CP (HL) RET NC ;there yet? LD C,' ' CALL OUTCHAR ;nope, keep going. JP NEWLN1 ; ; Output a (cr) (lf) to the console device (screen). ; OUTCRLF:LD C,CR CALL OUTCHAR LD C,LF JP OUTCHAR ; ; Print message pointed to by (BC). It will end with a '$'. ; PRTMESG:LD A,(BC) ;check for terminating character. CP '$' RET Z INC BC PUSH BC ;otherwise, bump pointer and print it. LD C,A CALL OUTCON POP BC JP PRTMESG ; ; Function to execute a buffered read. ; RDBUFF: LD A,(CURPOS) ;use present location as starting one. LD (STARTING),A LD HL,(PARAMS) ;get the maximum buffer space. LD C,(HL) INC HL ;point to first available space. PUSH HL ;and save. LD B,0 ;keep a character count. RDBUF1: PUSH BC PUSH HL RDBUF2: CALL GETCHAR ;get the next input character. AND 7FH ;strip bit 7. POP HL ;reset registers. POP BC CP CR ;en of the line? JP Z,RDBUF17 CP LF JP Z,RDBUF17 CP BS ;how about a backspace? JP NZ,RDBUF3 LD A,B ;yes, but ignore at the beginning of the line. OR A JP Z,RDBUF1 DEC B ;ok, update counter. LD A,(CURPOS) ;if we backspace to the start of the line, LD (OUTFLAG),A ;treat as a cancel (control-x). JP RDBUF10 RDBUF3: CP DEL ;user typed a rubout? JP NZ,RDBUF4 LD A,B ;ignore at the start of the line. OR A JP Z,RDBUF1 LD A,(HL) ;ok, echo the prevoius character. DEC B ;and reset pointers (counters). DEC HL JP RDBUF15 RDBUF4: CP CNTRLE ;physical end of line? JP NZ,RDBUF5 PUSH BC ;yes, do it. PUSH HL CALL OUTCRLF XOR A ;and update starting position. LD (STARTING),A JP RDBUF2 RDBUF5: CP CNTRLP ;control-p? JP NZ,RDBUF6 PUSH HL ;yes, flip the print flag filp-flop byte. LD HL,PRTFLAG LD A,1 ;PRTFLAG=1-PRTFLAG SUB (HL) LD (HL),A POP HL JP RDBUF1 RDBUF6: CP CNTRLX ;control-x (cancel)? JP NZ,RDBUF8 POP HL RDBUF7: LD A,(STARTING) ;yes, backup the cursor to here. LD HL,CURPOS CP (HL) JP NC,RDBUFF ;done yet? DEC (HL) ;no, decrement pointer and output back up one space. CALL BACKUP JP RDBUF7 RDBUF8: CP CNTRLU ;cntrol-u (cancel line)? JP NZ,RDBUF9 CALL NEWLINE ;start a new line. POP HL JP RDBUFF RDBUF9: CP CNTRLR ;control-r? JP NZ,RDBUF14 RDBUF10:PUSH BC ;yes, start a new line and retype the old one. CALL NEWLINE POP BC POP HL PUSH HL PUSH BC RDBUF11:LD A,B ;done whole line yet? OR A JP Z,RDBUF12 INC HL ;nope, get next character. LD C,(HL) DEC B ;count it. PUSH BC PUSH HL CALL SHOWIT ;and display it. POP HL POP BC JP RDBUF11 RDBUF12:PUSH HL ;done with line. If we were displaying LD A,(OUTFLAG) ;then update cursor position. OR A JP Z,RDBUF2 LD HL,CURPOS ;because this line is shorter, we must SUB (HL) ;back up the cursor (not the screen however) LD (OUTFLAG),A ;some number of positions. RDBUF13:CALL BACKUP ;note that as long as (OUTFLAG) is non LD HL,OUTFLAG ;zero, the screen will not be changed. DEC (HL) JP NZ,RDBUF13 JP RDBUF2 ;now just get the next character. ; ; Just a normal character, put this in our buffer and echo. ; RDBUF14:INC HL LD (HL),A ;store character. INC B ;and count it. RDBUF15:PUSH BC PUSH HL LD C,A ;echo it now. CALL SHOWIT POP HL POP BC LD A,(HL) ;was it an abort request? CP CNTRLC ;control-c abort? LD A,B JP NZ,RDBUF16 CP 1 ;only if at start of line. JP Z,0 RDBUF16:CP C ;nope, have we filled the buffer? JP C,RDBUF1 RDBUF17:POP HL ;yes end the line and return. LD (HL),B LD C,CR JP OUTCHAR ;output (cr) and return. ; ; Function to get a character from the console device. ; GETCON: CALL GETECHO ;get and echo. JP SETSTAT ;save status and return. ; ; Function to get a character from the tape reader device. ; GETRDR: CALL READER ;get a character from reader, set status and return. JP SETSTAT ; ; Function to perform direct console i/o. If (C) contains (FF) ; then this is an input request. If (C) contains (FE) then ; this is a status request. Otherwise we are to output (C). ; DIRCIO: LD A,C ;test for (FF). INC A JP Z,DIRC1 INC A ;test for (FE). JP Z,CONST JP CONOUT ;just output (C). DIRC1: CALL CONST ;this is an input request. OR A JP Z,GOBACK1 ;not ready? Just return (directly). CALL CONIN ;yes, get character. JP SETSTAT ;set status and return. ; ; Function to return the i/o byte. ; GETIOB: LD A,(IOBYTE) JP SETSTAT ; ; Function to set the i/o byte. ; SETIOB: LD HL,IOBYTE LD (HL),C RET ; ; Function to print the character string pointed to by (DE) ; on the console device. The string ends with a '$'. ; PRTSTR: EX DE,HL LD C,L LD B,H ;now (BC) points to it. JP PRTMESG ; ; Function to interigate the console device. ; GETCSTS:CALL CKCONSOL ; ; Get here to set the status and return to the cleanup ; section. Then back to the user. ; SETSTAT:LD (STATUS),A RTN: RET ; ; Set the status to 1 (read or write error code). ; IOERR1: LD A,1 JP SETSTAT ; OUTFLAG:DEFB 0 ;output flag (non zero means no output). STARTING: DEFB 2 ;starting position for cursor. CURPOS: DEFB 0 ;cursor position (0=start of line). PRTFLAG:DEFB 0 ;printer flag (control-p toggle). List if non zero. CHARBUF:DEFB 0 ;single input character buffer. ; ; Stack area for BDOS calls. ; USRSTACK: DEFW 0 ;save users stack pointer here. ; DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 STKAREA EQU $ ;end of stack area. ; USERNO: DEFB 0 ;current user number. ACTIVE: DEFB 0 ;currently active drive. PARAMS: DEFW 0 ;save (DE) parameters here on entry. STATUS: DEFW 0 ;status returned from bdos function. ; ; Select error occured, jump to error routine. ; SLCTERR:LD HL,BADSLCT ; ; Jump to (HL) indirectly. ; JUMPHL: LD E,(HL) INC HL LD D,(HL) ;now (DE) contain the desired address. EX DE,HL JP (HL) ; ; Block move. (DE) to (HL), (C) bytes total. ; DE2HL: INC C ;is count down to zero? DE2HL1: DEC C RET Z ;yes, we are done. LD A,(DE) ;no, move one more byte. LD (HL),A INC DE INC HL JP DE2HL1 ;and repeat. ; ; Select the desired drive. ; SELECT: LD A,(ACTIVE) ;get active disk. and 3 LD C,A CALL SELDSK ;select it. LD A,H ;valid drive? OR L ;valid drive? RET Z ;return if not. ; ; Here, the BIOS returned the address of the parameter block ; in (HL). We will extract the necessary pointers and save them. ; LD E,(HL) ;yes, get address of translation table into (DE). INC HL LD D,(HL) INC HL LD (SCRATCH1),HL ;save pointers to scratch areas. INC HL INC HL LD (SCRATCH2),HL ;ditto. INC HL INC HL LD (SCRATCH3),HL ;ditto. INC HL INC HL EX DE,HL ;now save the translation table address. LD (XLATE),HL LD HL,DIRBUF ;put the next 8 bytes here. LD C,8 ;they consist of the directory buffer CALL DE2HL ;pointer, parameter block pointer, LD HL,(DISKPB) ;check and allocation vectors. EX DE,HL LD HL,SECTORS ;move parameter block into our ram. LD C,15 ;it is 15 bytes long. CALL DE2HL LD HL,(DSKSIZE) ;check disk size. LD A,H ;more than 256 blocks on this? LD HL,BIGDISK LD (HL),0FFH ;set to samll. OR A JP Z,SELECT1 LD (HL),0 ;wrong, set to large. SELECT1:LD A,0FFH ;clear the zero flag. OR A RET ; ; Routine to home the disk track head and clear pointers. ; HOMEDRV:CALL HOME ;home the head. XOR A LD HL,(SCRATCH2) ;set our track pointer also. LD (HL),A INC HL LD (HL),A LD HL,(SCRATCH3) ;and our sector pointer. LD (HL),A INC HL LD (HL),A RET ; ; Do the actual disk read and check the error return status. ; DOREAD: CALL READ JP IORET ; ; Do the actual disk write and handle any bios error. ; DOWRITE:CALL WRITE IORET: OR A RET Z ;return unless an error occured. LD HL,BADSCTR ;bad read/write on this sector. JP JUMPHL ; ; Routine to select the track and sector that the desired ; block number falls in. ; TRKSEC: LD HL,(FILEPOS) ;get position of last accessed file LD C,2 ;in directory and compute sector #. CALL SHIFTR ;sector #=file-position/4. LD (BLKNMBR),HL ;save this as the block number of interest. LD (CKSUMTBL),HL ;what's it doing here too? ; ; if the sector number has already been set (BLKNMBR), enter ; at this point. ; TRKSEC1:LD HL,BLKNMBR LD C,(HL) ;move sector number into (BC). INC HL LD B,(HL) LD HL,(SCRATCH3) ;get current sector number and LD E,(HL) ;move this into (DE). INC HL LD D,(HL) LD HL,(SCRATCH2) ;get current track number. LD A,(HL) ;and this into (HL). INC HL LD H,(HL) LD L,A TRKSEC2:LD A,C ;is desired sector before current one? SUB E LD A,B SBC A,D JP NC,TRKSEC3 PUSH HL ;yes, decrement sectors by one track. LD HL,(SECTORS) ;get sectors per track. LD A,E SUB L LD E,A LD A,D SBC A,H LD D,A ;now we have backed up one full track. POP HL DEC HL ;adjust track counter. JP TRKSEC2 TRKSEC3:PUSH HL ;desired sector is after current one. LD HL,(SECTORS) ;get sectors per track. ADD HL,DE ;bump sector pointer to next track. JP C,TRKSEC4 LD A,C ;is desired sector now before current one? SUB L LD A,B SBC A,H JP C,TRKSEC4 EX DE,HL ;not yes, increment track counter POP HL ;and continue until it is. INC HL JP TRKSEC3 ; ; here we have determined the track number that contains the ; desired sector. ; TRKSEC4:POP HL ;get track number (HL). PUSH BC PUSH DE PUSH HL EX DE,HL LD HL,(OFFSET) ;adjust for first track offset. ADD HL,DE LD B,H LD C,L CALL SETTRK ;select this track. POP DE ;reset current track pointer. LD HL,(SCRATCH2) LD (HL),E INC HL LD (HL),D POP DE LD HL,(SCRATCH3) ;reset the first sector on this track. LD (HL),E INC HL LD (HL),D POP BC LD A,C ;now subtract the desired one. SUB E ;to make it relative (1-# sectors/track). LD C,A LD A,B SBC A,D LD B,A LD HL,(XLATE) ;translate this sector according to this table. EX DE,HL CALL SECTRN ;let the bios translate it. LD C,L LD B,H JP SETSEC ;and select it. ; ; Compute block number from record number (SAVNREC) and ; extent number (SAVEXT). ; GETBLOCK: LD HL,BLKSHFT ;get logical to physical conversion. LD C,(HL) ;note that this is base 2 log of ratio. LD A,(SAVNREC) ;get record number. GETBLK1:OR A ;compute (A)=(A)/2^BLKSHFT. RRA DEC C JP NZ,GETBLK1 LD B,A ;save result in (B). LD A,8 SUB (HL) LD C,A ;compute (C)=8-BLKSHFT. LD A,(SAVEXT) GETBLK2:DEC C ;compute (A)=SAVEXT*2^(8-BLKSHFT). JP Z,GETBLK3 OR A RLA JP GETBLK2 GETBLK3:ADD A,B RET ; ; Routine to extract the (BC) block byte from the fcb pointed ; to by (PARAMS). If this is a big-disk, then these are 16 bit ; block numbers, else they are 8 bit numbers. ; Number is returned in (HL). ; EXTBLK: LD HL,(PARAMS) ;get fcb address. LD DE,16 ;block numbers start 16 bytes into fcb. ADD HL,DE ADD HL,BC LD A,(BIGDISK) ;are we using a big-disk? OR A JP Z,EXTBLK1 LD L,(HL) ;no, extract an 8 bit number from the fcb. LD H,0 RET EXTBLK1:ADD HL,BC ;yes, extract a 16 bit number. LD E,(HL) INC HL LD D,(HL) EX DE,HL ;return in (HL). RET ; ; Compute block number. ; COMBLK: CALL GETBLOCK LD C,A LD B,0 CALL EXTBLK LD (BLKNMBR),HL RET ; ; Check for a zero block number (unused). ; CHKBLK: LD HL,(BLKNMBR) LD A,L ;is it zero? OR H RET ; ; Adjust physical block (BLKNMBR) and convert to logical ; sector (LOGSECT). This is the starting sector of this block. ; The actual sector of interest is then added to this and the ; resulting sector number is stored back in (BLKNMBR). This ; will still have to be adjusted for the track number. ; LOGICAL:LD A,(BLKSHFT) ;get log2(physical/logical sectors). LD HL,(BLKNMBR) ;get physical sector desired. LOGICL1:ADD HL,HL ;compute logical sector number. DEC A ;note logical sectors are 128 bytes long. JP NZ,LOGICL1 LD (LOGSECT),HL ;save logical sector. LD A,(BLKMASK) ;get block mask. LD C,A LD A,(SAVNREC) ;get next sector to access. AND C ;extract the relative position within physical block. OR L ;and add it too logical sector. LD L,A LD (BLKNMBR),HL ;and store. RET ; ; Set (HL) to point to extent byte in fcb. ; SETEXT: LD HL,(PARAMS) LD DE,12 ;it is the twelth byte. ADD HL,DE RET ; ; Set (HL) to point to record count byte in fcb and (DE) to ; next record number byte. ; SETHLDE:LD HL,(PARAMS) LD DE,15 ;record count byte (#15). ADD HL,DE EX DE,HL LD HL,17 ;next record number (#32). ADD HL,DE RET ; ; Save current file data from fcb. ; STRDATA:CALL SETHLDE LD A,(HL) ;get and store record count byte. LD (SAVNREC),A EX DE,HL LD A,(HL) ;get and store next record number byte. LD (SAVNXT),A CALL SETEXT ;point to extent byte. LD A,(EXTMASK) ;get extent mask. AND (HL) LD (SAVEXT),A ;and save extent here. RET ; ; Set the next record to access. If (MODE) is set to 2, then ; the last record byte (SAVNREC) has the correct number to access. ; For sequential access, (MODE) will be equal to 1. ; SETNREC:CALL SETHLDE LD A,(MODE) ;get sequential flag (=1). CP 2 ;a 2 indicates that no adder is needed. JP NZ,STNREC1 XOR A ;clear adder (random access?). STNREC1:LD C,A LD A,(SAVNREC) ;get last record number. ADD A,C ;increment record count. LD (HL),A ;and set fcb's next record byte. EX DE,HL LD A,(SAVNXT) ;get next record byte from storage. LD (HL),A ;and put this into fcb as number of records used. RET ; ; Shift (HL) right (C) bits. ; SHIFTR: INC C SHIFTR1:DEC C RET Z LD A,H OR A RRA LD H,A LD A,L RRA LD L,A JP SHIFTR1 ; ; Compute the check-sum for the directory buffer. Return ; integer sum in (A). ; CHECKSUM: LD C,128 ;length of buffer. LD HL,(DIRBUF) ;get its location. XOR A ;clear summation byte. CHKSUM1:ADD A,(HL) ;and compute sum ignoring carries. INC HL DEC C JP NZ,CHKSUM1 RET ; ; Shift (HL) left (C) bits. ; SHIFTL: INC C SHIFTL1:DEC C RET Z ADD HL,HL ;shift left 1 bit. JP SHIFTL1 ; ; Routine to set a bit in a 16 bit value contained in (BC). ; The bit set depends on the current drive selection. ; SETBIT: PUSH BC ;save 16 bit word. LD A,(ACTIVE) ;get active drive. LD C,A LD HL,1 CALL SHIFTL ;shift bit 0 into place. POP BC ;now 'or' this with the original word. LD A,C OR L LD L,A ;low byte done, do high byte. LD A,B OR H LD H,A RET ; ; Extract the write protect status bit for the current drive. ; The result is returned in (A), bit 0. ; GETWPRT:LD HL,(WRTPRT) ;get status bytes. LD A,(ACTIVE) ;which drive is current? LD C,A CALL SHIFTR ;shift status such that bit 0 is the LD A,L ;one of interest for this drive. AND 01H ;and isolate it. RET ; ; Function to write protect the current disk. ; WRTPRTD:LD HL,WRTPRT ;point to status word. LD C,(HL) ;set (BC) equal to the status. INC HL LD B,(HL) CALL SETBIT ;and set this bit according to current drive. LD (WRTPRT),HL ;then save. LD HL,(DIRSIZE) ;now save directory size limit. INC HL ;remember the last one. EX DE,HL LD HL,(SCRATCH1) ;and store it here. LD (HL),E ;put low byte. INC HL LD (HL),D ;then high byte. RET ; ; Check for a read only file. ; CHKROFL:CALL FCB2HL ;set (HL) to file entry in directory buffer. CKROF1: LD DE,9 ;look at bit 7 of the ninth byte. ADD HL,DE LD A,(HL) RLA RET NC ;return if ok. LD HL,ROFILE ;else, print error message and terminate. JP JUMPHL ; ; Check the write protect status of the active disk. ; CHKWPRT:CALL GETWPRT RET Z ;return if ok. LD HL,RODISK ;else print message and terminate. JP JUMPHL ; ; Routine to set (HL) pointing to the proper entry in the ; directory buffer. ; FCB2HL: LD HL,(DIRBUF) ;get address of buffer. LD A,(FCBPOS) ;relative position of file. ; ; Routine to add (A) to (HL). ; ADDA2HL:ADD A,L LD L,A RET NC INC H ;take care of any carry. RET ; ; Routine to get the 's2' byte from the fcb supplied in ; the initial parameter specification. ; GETS2: LD HL,(PARAMS) ;get address of fcb. LD DE,14 ;relative position of 's2'. ADD HL,DE LD A,(HL) ;extract this byte. RET ; ; Clear the 's2' byte in the fcb. ; CLEARS2:CALL GETS2 ;this sets (HL) pointing to it. LD (HL),0 ;now clear it. RET ; ; Set bit 7 in the 's2' byte of the fcb. ; SETS2B7:CALL GETS2 ;get the byte. OR 80H ;and set bit 7. LD (HL),A ;then store. RET ; ; Compare (FILEPOS) with (SCRATCH1) and set flags based on ; the difference. This checks to see if there are more file ; names in the directory. We are at (FILEPOS) and there are ; (SCRATCH1) of them to check. ; MOREFLS:LD HL,(FILEPOS) ;we are here. EX DE,HL LD HL,(SCRATCH1) ;and don't go past here. LD A,E ;compute difference but don't keep. SUB (HL) INC HL LD A,D SBC A,(HL) ;set carry if no more names. RET ; ; Call this routine to prevent (SCRATCH1) from being greater ; than (FILEPOS). ; CHKNMBR:CALL MOREFLS ;SCRATCH1 too big? RET C INC DE ;yes, reset it to (FILEPOS). LD (HL),D DEC HL LD (HL),E RET ; ; Compute (HL)=(DE)-(HL) ; SUBHL: LD A,E ;compute difference. SUB L LD L,A ;store low byte. LD A,D SBC A,H LD H,A ;and then high byte. RET ; ; Set the directory checksum byte. ; SETDIR: LD C,0FFH ; ; Routine to set or compare the directory checksum byte. If ; (C)=0ffh, then this will set the checksum byte. Else the byte ; will be checked. If the check fails (the disk has been changed), ; then this disk will be write protected. ; CHECKDIR: LD HL,(CKSUMTBL) EX DE,HL LD HL,(ALLOC1) CALL SUBHL RET NC ;ok if (CKSUMTBL) > (ALLOC1), so return. PUSH BC CALL CHECKSUM ;else compute checksum. LD HL,(CHKVECT) ;get address of checksum table. EX DE,HL LD HL,(CKSUMTBL) ADD HL,DE ;set (HL) to point to byte for this drive. POP BC INC C ;set or check ? JP Z,CHKDIR1 CP (HL) ;check them. RET Z ;return if they are the same. CALL MOREFLS ;not the same, do we care? RET NC CALL WRTPRTD ;yes, mark this as write protected. RET CHKDIR1:LD (HL),A ;just set the byte. RET ; ; Do a write to the directory of the current disk. ; DIRWRITE: CALL SETDIR ;set checksum byte. CALL DIRDMA ;set directory dma address. LD C,1 ;tell the bios to actually write. CALL DOWRITE ;then do the write. JP DEFDMA ; ; Read from the directory. ; DIRREAD:CALL DIRDMA ;set the directory dma address. CALL DOREAD ;and read it. ; ; Routine to set the dma address to the users choice. ; DEFDMA: LD HL,USERDMA ;reset the default dma address and return. JP DIRDMA1 ; ; Routine to set the dma address for directory work. ; DIRDMA: LD HL,DIRBUF ; ; Set the dma address. On entry, (HL) points to ; word containing the desired dma address. ; DIRDMA1:LD C,(HL) INC HL LD B,(HL) ;setup (BC) and go to the bios to set it. JP SETDMA ; ; Move the directory buffer into user's dma space. ; MOVEDIR:LD HL,(DIRBUF) ;buffer is located here, and EX DE,HL LD HL,(USERDMA) ; put it here. LD C,128 ;this is its length. JP DE2HL ;move it now and return. ; ; Check (FILEPOS) and set the zero flag if it equals 0ffffh. ; CKFILPOS: LD HL,FILEPOS LD A,(HL) INC HL CP (HL) ;are both bytes the same? RET NZ INC A ;yes, but are they each 0ffh? RET ; ; Set location (FILEPOS) to 0ffffh. ; STFILPOS: LD HL,0FFFFH LD (FILEPOS),HL RET ; ; Move on to the next file position within the current ; directory buffer. If no more exist, set pointer to 0ffffh ; and the calling routine will check for this. Enter with (C) ; equal to 0ffh to cause the checksum byte to be set, else we ; will check this disk and set write protect if checksums are ; not the same (applies only if another directory sector must ; be read). ; NXENTRY:LD HL,(DIRSIZE) ;get directory entry size limit. EX DE,HL LD HL,(FILEPOS) ;get current count. INC HL ;go on to the next one. LD (FILEPOS),HL CALL SUBHL ;(HL)=(DIRSIZE)-(FILEPOS) JP NC,NXENT1 ;is there more room left? JP STFILPOS ;no. Set this flag and return. NXENT1: LD A,(FILEPOS) ;get file position within directory. AND 03H ;only look within this sector (only 4 entries fit). LD B,5 ;convert to relative position (32 bytes each). NXENT2: ADD A,A ;note that this is not efficient code. DEC B ;5 'ADD A's would be better. JP NZ,NXENT2 LD (FCBPOS),A ;save it as position of fcb. OR A RET NZ ;return if we are within buffer. PUSH BC CALL TRKSEC ;we need the next directory sector. CALL DIRREAD POP BC JP CHECKDIR ; ; Routine to to get a bit from the disk space allocation ; map. It is returned in (A), bit position 0. On entry to here, ; set (BC) to the block number on the disk to check. ; On return, (D) will contain the original bit position for ; this block number and (HL) will point to the address for it. ; CKBITMAP: LD A,C ;determine bit number of interest. AND 07H ;compute (D)=(E)=(C and 7)+1. INC A LD E,A ;save particular bit number. LD D,A ; ; compute (BC)=(BC)/8. ; LD A,C RRCA ;now shift right 3 bits. RRCA RRCA AND 1FH ;and clear bits 7,6,5. LD C,A LD A,B ADD A,A ;now shift (B) into bits 7,6,5. ADD A,A ADD A,A ADD A,A ADD A,A OR C ;and add in (C). LD C,A ;ok, (C) ha been completed. LD A,B ;is there a better way of doing this? RRCA RRCA RRCA AND 1FH LD B,A ;and now (B) is completed. ; ; use this as an offset into the disk space allocation ; table. ; LD HL,(ALOCVECT) ADD HL,BC LD A,(HL) ;now get correct byte. CKBMAP1:RLCA ;get correct bit into position 0. DEC E JP NZ,CKBMAP1 RET ; ; Set or clear the bit map such that block number (BC) will be marked ; as used. On entry, if (E)=0 then this bit will be cleared, if it equals ; 1 then it will be set (don't use anyother values). ; STBITMAP: PUSH DE CALL CKBITMAP ;get the byte of interest. AND 0FEH ;clear the affected bit. POP BC OR C ;and now set it acording to (C). ; ; entry to restore the original bit position and then store ; in table. (A) contains the value, (D) contains the bit ; position (1-8), and (HL) points to the address within the ; space allocation table for this byte. ; STBMAP1:RRCA ;restore original bit position. DEC D JP NZ,STBMAP1 LD (HL),A ;and stor byte in table. RET ; ; Set/clear space used bits in allocation map for this file. ; On entry, (C)=1 to set the map and (C)=0 to clear it. ; SETFILE:CALL FCB2HL ;get address of fcb LD DE,16 ADD HL,DE ;get to block number bytes. PUSH BC LD C,17 ;check all 17 bytes (max) of table. SETFL1: POP DE DEC C ;done all bytes yet? RET Z PUSH DE LD A,(BIGDISK) ;check disk size for 16 bit block numbers. OR A JP Z,SETFL2 PUSH BC ;only 8 bit numbers. set (BC) to this one. PUSH HL LD C,(HL) ;get low byte from table, always LD B,0 ;set high byte to zero. JP SETFL3 SETFL2: DEC C ;for 16 bit block numbers, adjust counter. PUSH BC LD C,(HL) ;now get both the low and high bytes. INC HL LD B,(HL) PUSH HL SETFL3: LD A,C ;block used? OR B JP Z,SETFL4 LD HL,(DSKSIZE) ;is this block number within the LD A,L ;space on the disk? SUB C LD A,H SBC A,B CALL NC,STBITMAP ;yes, set the proper bit. SETFL4: POP HL ;point to next block number in fcb. INC HL POP BC JP SETFL1 ; ; Construct the space used allocation bit map for the active ; drive. If a file name starts with '$' and it is under the ; current user number, then (STATUS) is set to minus 1. Otherwise ; it is not set at all. ; BITMAP: LD HL,(DSKSIZE) ;compute size of allocation table. LD C,3 CALL SHIFTR ;(HL)=(HL)/8. INC HL ;at lease 1 byte. LD B,H LD C,L ;set (BC) to the allocation table length. ; ; Initialize the bitmap for this drive. Right now, the first ; two bytes are specified by the disk parameter block. However ; a patch could be entered here if it were necessary to setup ; this table in a special mannor. For example, the bios could ; determine locations of 'bad blocks' and set them as already ; 'used' in the map. ; LD HL,(ALOCVECT) ;now zero out the table now. BITMAP1:LD (HL),0 INC HL DEC BC LD A,B OR C JP NZ,BITMAP1 LD HL,(ALLOC0) ;get initial space used by directory. EX DE,HL LD HL,(ALOCVECT) ;and put this into map. LD (HL),E INC HL LD (HL),D ; ; End of initialization portion. ; CALL HOMEDRV ;now home the drive. LD HL,(SCRATCH1) LD (HL),3 ;force next directory request to read INC HL ;in a sector. LD (HL),0 CALL STFILPOS ;clear initial file position also. BITMAP2:LD C,0FFH ;read next file name in directory CALL NXENTRY ;and set checksum byte. CALL CKFILPOS ;is there another file? RET Z CALL FCB2HL ;yes, get its address. LD A,0E5H CP (HL) ;empty file entry? JP Z,BITMAP2 LD A,(USERNO) ;no, correct user number? CP (HL) JP NZ,BITMAP3 INC HL LD A,(HL) ;yes, does name start with a '$'? SUB '$' JP NZ,BITMAP3 DEC A ;yes, set atatus to minus one. LD (STATUS),A BITMAP3:LD C,1 ;now set this file's space as used in bit map. CALL SETFILE CALL CHKNMBR ;keep (SCRATCH1) in bounds. JP BITMAP2 ; ; Set the status (STATUS) and return. ; STSTATUS: LD A,(FNDSTAT) JP SETSTAT ; ; Check extents in (A) and (C). Set the zero flag if they ; are the same. The number of 16k chunks of disk space that ; the directory extent covers is expressad is (EXTMASK+1). ; No registers are modified. ; SAMEXT: PUSH BC PUSH AF LD A,(EXTMASK) ;get extent mask and use it to CPL ;to compare both extent numbers. LD B,A ;save resulting mask here. LD A,C ;mask first extent and save in (C). AND B LD C,A POP AF ;now mask second extent and compare AND B ;with the first one. SUB C AND 1FH ;(* only check buts 0-4 *) POP BC ;the zero flag is set if they are the same. RET ;restore (BC) and return. ; ; Search for the first occurence of a file name. On entry, ; register (C) should contain the number of bytes of the fcb ; that must match. ; FINDFST:LD A,0FFH LD (FNDSTAT),A LD HL,COUNTER ;save character count. LD (HL),C LD HL,(PARAMS) ;get filename to match. LD (SAVEFCB),HL ;and save. CALL STFILPOS ;clear initial file position (set to 0ffffh). CALL HOMEDRV ;home the drive. ; ; Entry to locate the next occurence of a filename within the ; directory. The disk is not expected to have been changed. If ; it was, then it will be write protected. ; FINDNXT:LD C,0 ;write protect the disk if changed. CALL NXENTRY ;get next filename entry in directory. CALL CKFILPOS ;is file position = 0ffffh? JP Z,FNDNXT6 ;yes, exit now then. LD HL,(SAVEFCB) ;set (DE) pointing to filename to match. EX DE,HL LD A,(DE) CP 0E5H ;empty directory entry? JP Z,FNDNXT1 ;(* are we trying to reserect erased entries? *) PUSH DE CALL MOREFLS ;more files in directory? POP DE JP NC,FNDNXT6 ;no more. Exit now. FNDNXT1:CALL FCB2HL ;get address of this fcb in directory. LD A,(COUNTER) ;get number of bytes (characters) to check. LD C,A LD B,0 ;initialize byte position counter. FNDNXT2:LD A,C ;are we done with the compare? OR A JP Z,FNDNXT5 LD A,(DE) ;no, check next byte. CP '?' ;don't care about this character? JP Z,FNDNXT4 LD A,B ;get bytes position in fcb. CP 13 ;don't care about the thirteenth byte either. JP Z,FNDNXT4 CP 12 ;extent byte? LD A,(DE) JP Z,FNDNXT3 SUB (HL) ;otherwise compare characters. AND 7FH JP NZ,FINDNXT ;not the same, check next entry. JP FNDNXT4 ;so far so good, keep checking. FNDNXT3:PUSH BC ;check the extent byte here. LD C,(HL) CALL SAMEXT POP BC JP NZ,FINDNXT ;not the same, look some more. ; ; So far the names compare. Bump pointers to the next byte ; and continue until all (C) characters have been checked. ; FNDNXT4:INC DE ;bump pointers. INC HL INC B DEC C ;adjust character counter. JP FNDNXT2 FNDNXT5:LD A,(FILEPOS) ;return the position of this entry. AND 03H LD (STATUS),A LD HL,FNDSTAT LD A,(HL) RLA RET NC XOR A LD (HL),A RET ; ; Filename was not found. Set appropriate status. ; FNDNXT6:CALL STFILPOS ;set (FILEPOS) to 0ffffh. LD A,0FFH ;say not located. JP SETSTAT ; ; Erase files from the directory. Only the first byte of the ; fcb will be affected. It is set to (E5). ; ERAFILE:CALL CHKWPRT ;is disk write protected? LD C,12 ;only compare file names. CALL FINDFST ;get first file name. ERAFIL1:CALL CKFILPOS ;any found? RET Z ;nope, we must be done. CALL CHKROFL ;is file read only? CALL FCB2HL ;nope, get address of fcb and LD (HL),0E5H ;set first byte to 'empty'. LD C,0 ;clear the space from the bit map. CALL SETFILE CALL DIRWRITE ;now write the directory sector back out. CALL FINDNXT ;find the next file name. JP ERAFIL1 ;and repeat process. ; ; Look through the space allocation map (bit map) for the ; next available block. Start searching at block number (BC-1). ; The search procedure is to look for an empty block that is ; before the starting block. If not empty, look at a later ; block number. In this way, we return the closest empty block ; on either side of the 'target' block number. This will speed ; access on random devices. For serial devices, this should be ; changed to look in the forward direction first and then start ; at the front and search some more. ; ; On return, (DE)= block number that is empty and (HL) =0 ; if no empry block was found. ; FNDSPACE: LD D,B ;set (DE) as the block that is checked. LD E,C ; ; Look before target block. Registers (BC) are used as the lower ; pointer and (DE) as the upper pointer. ; FNDSPA1:LD A,C ;is block 0 specified? OR B JP Z,FNDSPA2 DEC BC ;nope, check previous block. PUSH DE PUSH BC CALL CKBITMAP RRA ;is this block empty? JP NC,FNDSPA3 ;yes. use this. ; ; Note that the above logic gets the first block that it finds ; that is empty. Thus a file could be written 'backward' making ; it very slow to access. This could be changed to look for the ; first empty block and then continue until the start of this ; empty space is located and then used that starting block. ; This should help speed up access to some files especially on ; a well used disk with lots of fairly small 'holes'. ; POP BC ;nope, check some more. POP DE ; ; Now look after target block. ; FNDSPA2:LD HL,(DSKSIZE) ;is block (DE) within disk limits? LD A,E SUB L LD A,D SBC A,H JP NC,FNDSPA4 INC DE ;yes, move on to next one. PUSH BC PUSH DE LD B,D LD C,E CALL CKBITMAP ;check it. RRA ;empty? JP NC,FNDSPA3 POP DE ;nope, continue searching. POP BC JP FNDSPA1 ; ; Empty block found. Set it as used and return with (HL) ; pointing to it (true?). ; FNDSPA3:RLA ;reset byte. INC A ;and set bit 0. CALL STBMAP1 ;update bit map. POP HL ;set return registers. POP DE RET ; ; Free block was not found. If (BC) is not zero, then we have ; not checked all of the disk space. ; FNDSPA4:LD A,C OR B JP NZ,FNDSPA1 LD HL,0 ;set 'not found' status. RET ; ; Move a complete fcb entry into the directory and write it. ; FCBSET: LD C,0 LD E,32 ;length of each entry. ; ; Move (E) bytes from the fcb pointed to by (PARAMS) into ; fcb in directory starting at relative byte (C). This updated ; directory buffer is then written to the disk. ; UPDATE: PUSH DE LD B,0 ;set (BC) to relative byte position. LD HL,(PARAMS) ;get address of fcb. ADD HL,BC ;compute starting byte. EX DE,HL CALL FCB2HL ;get address of fcb to update in directory. POP BC ;set (C) to number of bytes to change. CALL DE2HL UPDATE1:CALL TRKSEC ;determine the track and sector affected. JP DIRWRITE ;then write this sector out. ; ; Routine to change the name of all files on the disk with a ; specified name. The fcb contains the current name as the ; first 12 characters and the new name 16 bytes into the fcb. ; CHGNAMES: CALL CHKWPRT ;check for a write protected disk. LD C,12 ;match first 12 bytes of fcb only. CALL FINDFST ;get first name. LD HL,(PARAMS) ;get address of fcb. LD A,(HL) ;get user number. LD DE,16 ;move over to desired name. ADD HL,DE LD (HL),A ;keep same user number. CHGNAM1:CALL CKFILPOS ;any matching file found? RET Z ;no, we must be done. CALL CHKROFL ;check for read only file. LD C,16 ;start 16 bytes into fcb. LD E,12 ;and update the first 12 bytes of directory. CALL UPDATE CALL FINDNXT ;get te next file name. JP CHGNAM1 ;and continue. ; ; Update a files attributes. The procedure is to search for ; every file with the same name as shown in fcb (ignoring bit 7) ; and then to update it (which includes bit 7). No other changes ; are made. ; SAVEATTR: LD C,12 ;match first 12 bytes. CALL FINDFST ;look for first filename. SAVATR1:CALL CKFILPOS ;was one found? RET Z ;nope, we must be done. LD C,0 ;yes, update the first 12 bytes now. LD E,12 CALL UPDATE ;update filename and write directory. CALL FINDNXT ;and get the next file. JP SAVATR1 ;then continue until done. ; ; Open a file (name specified in fcb). ; OPENIT: LD C,15 ;compare the first 15 bytes. CALL FINDFST ;get the first one in directory. CALL CKFILPOS ;any at all? RET Z OPENIT1:CALL SETEXT ;point to extent byte within users fcb. LD A,(HL) ;and get it. PUSH AF ;save it and address. PUSH HL CALL FCB2HL ;point to fcb in directory. EX DE,HL LD HL,(PARAMS) ;this is the users copy. LD C,32 ;move it into users space. PUSH DE CALL DE2HL CALL SETS2B7 ;set bit 7 in 's2' byte (unmodified). POP DE ;now get the extent byte from this fcb. LD HL,12 ADD HL,DE LD C,(HL) ;into (C). LD HL,15 ;now get the record count byte into (B). ADD HL,DE LD B,(HL) POP HL ;keep the same extent as the user had originally. POP AF LD (HL),A LD A,C ;is it the same as in the directory fcb? CP (HL) LD A,B ;if yes, then use the same record count. JP Z,OPENIT2 LD A,0 ;if the user specified an extent greater than JP C,OPENIT2 ;the one in the directory, then set record count to 0. LD A,128 ;otherwise set to maximum. OPENIT2:LD HL,(PARAMS) ;set record count in users fcb to (A). LD DE,15 ADD HL,DE ;compute relative position. LD (HL),A ;and set the record count. RET ; ; Move two bytes from (DE) to (HL) if (and only if) (HL) ; point to a zero value (16 bit). ; Return with zero flag set it (DE) was moved. Registers (DE) ; and (HL) are not changed. However (A) is. ; MOVEWORD: LD A,(HL) ;check for a zero word. INC HL OR (HL) ;both bytes zero? DEC HL RET NZ ;nope, just return. LD A,(DE) ;yes, move two bytes from (DE) into LD (HL),A ;this zero space. INC DE INC HL LD A,(DE) LD (HL),A DEC DE ;don't disturb these registers. DEC HL RET ; ; Get here to close a file specified by (fcb). ; CLOSEIT:XOR A ;clear status and file position bytes. LD (STATUS),A LD (FILEPOS),A LD (FILEPOS+1),A CALL GETWPRT ;get write protect bit for this drive. RET NZ ;just return if it is set. CALL GETS2 ;else get the 's2' byte. AND 80H ;and look at bit 7 (file unmodified?). RET NZ ;just return if set. LD C,15 ;else look up this file in directory. CALL FINDFST CALL CKFILPOS ;was it found? RET Z ;just return if not. LD BC,16 ;set (HL) pointing to records used section. CALL FCB2HL ADD HL,BC EX DE,HL LD HL,(PARAMS) ;do the same for users specified fcb. ADD HL,BC LD C,16 ;this many bytes are present in this extent. CLOSEIT1: LD A,(BIGDISK) ;8 or 16 bit record numbers? OR A JP Z,CLOSEIT4 LD A,(HL) ;just 8 bit. Get one from users fcb. OR A LD A,(DE) ;now get one from directory fcb. JP NZ,CLOSEIT2 LD (HL),A ;users byte was zero. Update from directory. CLOSEIT2: OR A JP NZ,CLOSEIT3 LD A,(HL) ;directories byte was zero, update from users fcb. LD (DE),A CLOSEIT3: CP (HL) ;if neither one of these bytes were zero, JP NZ,CLOSEIT7 ;then close error if they are not the same. JP CLOSEIT5 ;ok so far, get to next byte in fcbs. CLOSEIT4: CALL MOVEWORD ;update users fcb if it is zero. EX DE,HL CALL MOVEWORD ;update directories fcb if it is zero. EX DE,HL LD A,(DE) ;if these two values are no different, CP (HL) ;then a close error occured. JP NZ,CLOSEIT7 INC DE ;check second byte. INC HL LD A,(DE) CP (HL) JP NZ,CLOSEIT7 DEC C ;remember 16 bit values. CLOSEIT5: INC DE ;bump to next item in table. INC HL DEC C ;there are 16 entries only. JP NZ,CLOSEIT1 ;continue if more to do. LD BC,0FFECH ;backup 20 places (extent byte). ADD HL,BC EX DE,HL ADD HL,BC LD A,(DE) CP (HL) ;directory's extent already greater than the JP C,CLOSEIT6 ;users extent? LD (HL),A ;no, update directory extent. LD BC,3 ;and update the record count byte in ADD HL,BC ;directories fcb. EX DE,HL ADD HL,BC LD A,(HL) ;get from user. LD (DE),A ;and put in directory. CLOSEIT6: LD A,0FFH ;set 'was open and is now closed' byte. LD (CLOSEFLG),A JP UPDATE1 ;update the directory now. CLOSEIT7: LD HL,STATUS ;set return status and then return. DEC (HL) RET ; ; Routine to get the next empty space in the directory. It ; will then be cleared for use. ; GETEMPTY: CALL CHKWPRT ;make sure disk is not write protected. LD HL,(PARAMS) ;save current parameters (fcb). PUSH HL LD HL,EMPTYFCB ;use special one for empty space. LD (PARAMS),HL LD C,1 ;search for first empty spot in directory. CALL FINDFST ;(* only check first byte *) CALL CKFILPOS ;none? POP HL LD (PARAMS),HL ;restore original fcb address. RET Z ;return if no more space. EX DE,HL LD HL,15 ;point to number of records for this file. ADD HL,DE LD C,17 ;and clear all of this space. XOR A GETMT1: LD (HL),A INC HL DEC C JP NZ,GETMT1 LD HL,13 ;clear the 's1' byte also. ADD HL,DE LD (HL),A CALL CHKNMBR ;keep (SCRATCH1) within bounds. CALL FCBSET ;write out this fcb entry to directory. JP SETS2B7 ;set 's2' byte bit 7 (unmodified at present). ; ; Routine to close the current extent and open the next one ; for reading. ; GETNEXT:XOR A LD (CLOSEFLG),A ;clear close flag. CALL CLOSEIT ;close this extent. CALL CKFILPOS RET Z ;not there??? LD HL,(PARAMS) ;get extent byte. LD BC,12 ADD HL,BC LD A,(HL) ;and increment it. INC A AND 1FH ;keep within range 0-31. LD (HL),A JP Z,GTNEXT1 ;overflow? LD B,A ;mask extent byte. LD A,(EXTMASK) AND B LD HL,CLOSEFLG ;check close flag (0ffh is ok). AND (HL) JP Z,GTNEXT2 ;if zero, we must read in next extent. JP GTNEXT3 ;else, it is already in memory. GTNEXT1:LD BC,2 ;Point to the 's2' byte. ADD HL,BC INC (HL) ;and bump it. LD A,(HL) ;too many extents? AND 0FH JP Z,GTNEXT5 ;yes, set error code. ; ; Get here to open the next extent. ; GTNEXT2:LD C,15 ;set to check first 15 bytes of fcb. CALL FINDFST ;find the first one. CALL CKFILPOS ;none available? JP NZ,GTNEXT3 LD A,(RDWRTFLG) ;no extent present. Can we open an empty one? INC A ;0ffh means reading (so not possible). JP Z,GTNEXT5 ;or an error. CALL GETEMPTY ;we are writing, get an empty entry. CALL CKFILPOS ;none? JP Z,GTNEXT5 ;error if true. JP GTNEXT4 ;else we are almost done. GTNEXT3:CALL OPENIT1 ;open this extent. GTNEXT4:CALL STRDATA ;move in updated data (rec #, extent #, etc.) XOR A ;clear status and return. JP SETSTAT ; ; Error in extending the file. Too many extents were needed ; or not enough space on the disk. ; GTNEXT5:CALL IOERR1 ;set error code, clear bit 7 of 's2' JP SETS2B7 ;so this is not written on a close. ; ; Read a sequential file. ; RDSEQ: LD A,1 ;set sequential access mode. LD (MODE),A RDSEQ1: LD A,0FFH ;don't allow reading unwritten space. LD (RDWRTFLG),A CALL STRDATA ;put rec# and ext# into fcb. LD A,(SAVNREC) ;get next record to read. LD HL,SAVNXT ;get number of records in extent. CP (HL) ;within this extent? JP C,RDSEQ2 CP 128 ;no. Is this extent fully used? JP NZ,RDSEQ3 ;no. End-of-file. CALL GETNEXT ;yes, open the next one. XOR A ;reset next record to read. LD (SAVNREC),A LD A,(STATUS) ;check on open, successful? OR A JP NZ,RDSEQ3 ;no, error. RDSEQ2: CALL COMBLK ;ok. compute block number to read. CALL CHKBLK ;check it. Within bounds? JP Z,RDSEQ3 ;no, error. CALL LOGICAL ;convert (BLKNMBR) to logical sector (128 byte). CALL TRKSEC1 ;set the track and sector for this block #. CALL DOREAD ;and read it. JP SETNREC ;and set the next record to be accessed. ; ; Read error occured. Set status and return. ; RDSEQ3: JP IOERR1 ; ; Write the next sequential record. ; WTSEQ: LD A,1 ;set sequential access mode. LD (MODE),A WTSEQ1: LD A,0 ;allow an addition empty extent to be opened. LD (RDWRTFLG),A CALL CHKWPRT ;check write protect status. LD HL,(PARAMS) CALL CKROF1 ;check for read only file, (HL) already set to fcb. CALL STRDATA ;put updated data into fcb. LD A,(SAVNREC) ;get record number to write. CP 128 ;within range? JP NC,IOERR1 ;no, error(?). CALL COMBLK ;compute block number. CALL CHKBLK ;check number. LD C,0 ;is there one to write to? JP NZ,WTSEQ6 ;yes, go do it. CALL GETBLOCK ;get next block number within fcb to use. LD (RELBLOCK),A ;and save. LD BC,0 ;start looking for space from the start OR A ;if none allocated as yet. JP Z,WTSEQ2 LD C,A ;extract previous block number from fcb DEC BC ;so we can be closest to it. CALL EXTBLK LD B,H LD C,L WTSEQ2: CALL FNDSPACE ;find the next empty block nearest number (BC). LD A,L ;check for a zero number. OR H JP NZ,WTSEQ3 LD A,2 ;no more space? JP SETSTAT WTSEQ3: LD (BLKNMBR),HL ;save block number to access. EX DE,HL ;put block number into (DE). LD HL,(PARAMS) ;now we must update the fcb for this LD BC,16 ;newly allocated block. ADD HL,BC LD A,(BIGDISK) ;8 or 16 bit block numbers? OR A LD A,(RELBLOCK) ;(* update this entry *) JP Z,WTSEQ4 ;zero means 16 bit ones. CALL ADDA2HL ;(HL)=(HL)+(A) LD (HL),E ;store new block number. JP WTSEQ5 WTSEQ4: LD C,A ;compute spot in this 16 bit table. LD B,0 ADD HL,BC ADD HL,BC LD (HL),E ;stuff block number (DE) there. INC HL LD (HL),D WTSEQ5: LD C,2 ;set (C) to indicate writing to un-used disk space. WTSEQ6: LD A,(STATUS) ;are we ok so far? OR A RET NZ PUSH BC ;yes, save write flag for bios (register C). CALL LOGICAL ;convert (BLKNMBR) over to loical sectors. LD A,(MODE) ;get access mode flag (1=sequential, DEC A ;0=random, 2=special?). DEC A JP NZ,WTSEQ9 ; ; Special random i/o from function #40. Maybe for M/PM, but the ; current block, if it has not been written to, will be zeroed ; out and then written (reason?). ; POP BC PUSH BC LD A,C ;get write status flag (2=writing unused space). DEC A DEC A JP NZ,WTSEQ9 PUSH HL LD HL,(DIRBUF) ;zero out the directory buffer. LD D,A ;note that (A) is zero here. WTSEQ7: LD (HL),A INC HL INC D ;do 128 bytes. JP P,WTSEQ7 CALL DIRDMA ;tell the bios the dma address for directory access. LD HL,(LOGSECT) ;get sector that starts current block. LD C,2 ;set 'writing to unused space' flag. WTSEQ8: LD (BLKNMBR),HL ;save sector to write. PUSH BC CALL TRKSEC1 ;determine its track and sector numbers. POP BC CALL DOWRITE ;now write out 128 bytes of zeros. LD HL,(BLKNMBR) ;get sector number. LD C,0 ;set normal write flag. LD A,(BLKMASK) ;determine if we have written the entire LD B,A ;physical block. AND L CP B INC HL ;prepare for the next one. JP NZ,WTSEQ8 ;continue until (BLKMASK+1) sectors written. POP HL ;reset next sector number. LD (BLKNMBR),HL CALL DEFDMA ;and reset dma address. ; ; Normal disk write. Set the desired track and sector then ; do the actual write. ; WTSEQ9: CALL TRKSEC1 ;determine track and sector for this write. POP BC ;get write status flag. PUSH BC CALL DOWRITE ;and write this out. POP BC LD A,(SAVNREC) ;get number of records in file. LD HL,SAVNXT ;get last record written. CP (HL) JP C,WTSEQ10 LD (HL),A ;we have to update record count. INC (HL) LD C,2 ; ;* This area has been patched to correct disk update problem ;* when using blocking and de-blocking in the BIOS. ; WTSEQ10:NOP ;was 'dcr c' NOP ;was 'dcr c' LD HL,0 ;was 'jnz wtseq99' ; ; * End of patch. ; PUSH AF CALL GETS2 ;set 'extent written to' flag. AND 7FH ;(* clear bit 7 *) LD (HL),A POP AF ;get record count for this extent. WTSEQ99:CP 127 ;is it full? JP NZ,WTSEQ12 LD A,(MODE) ;yes, are we in sequential mode? CP 1 JP NZ,WTSEQ12 CALL SETNREC ;yes, set next record number. CALL GETNEXT ;and get next empty space in directory. LD HL,STATUS ;ok? LD A,(HL) OR A JP NZ,WTSEQ11 DEC A ;yes, set record count to -1. LD (SAVNREC),A WTSEQ11:LD (HL),0 ;clear status. WTSEQ12:JP SETNREC ;set next record to access. ; ; For random i/o, set the fcb for the desired record number ; based on the 'r0,r1,r2' bytes. These bytes in the fcb are ; used as follows: ; ; fcb+35 fcb+34 fcb+33 ; | 'r-2' | 'r-1' | 'r-0' | ; |7 0 | 7 0 | 7 0| ; |0 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0 | 0 0 0 0 0 0 0 0| ; | overflow | | extra | extent | record # | ; | ______________| |_extent|__number___|_____________| ; also 's2' ; ; On entry, register (C) contains 0ffh if this is a read ; and thus we can not access unwritten disk space. Otherwise, ; another extent will be opened (for writing) if required. ; POSITION: XOR A ;set random i/o flag. LD (MODE),A ; ; Special entry (function #40). M/PM ? ; POSITN1:PUSH BC ;save read/write flag. LD HL,(PARAMS) ;get address of fcb. EX DE,HL LD HL,33 ;now get byte 'r0'. ADD HL,DE LD A,(HL) AND 7FH ;keep bits 0-6 for the record number to access. PUSH AF LD A,(HL) ;now get bit 7 of 'r0' and bits 0-3 of 'r1'. RLA INC HL LD A,(HL) RLA AND 1FH ;and save this in bits 0-4 of (C). LD C,A ;this is the extent byte. LD A,(HL) ;now get the extra extent byte. RRA RRA RRA RRA AND 0FH LD B,A ;and save it in (B). POP AF ;get record number back to (A). INC HL ;check overflow byte 'r2'. LD L,(HL) INC L DEC L LD L,6 ;prepare for error. JP NZ,POSITN5 ;out of disk space error. LD HL,32 ;store record number into fcb. ADD HL,DE LD (HL),A LD HL,12 ;and now check the extent byte. ADD HL,DE LD A,C SUB (HL) ;same extent as before? JP NZ,POSITN2 LD HL,14 ;yes, check extra extent byte 's2' also. ADD HL,DE LD A,B SUB (HL) AND 7FH JP Z,POSITN3 ;same, we are almost done then. ; ; Get here when another extent is required. ; POSITN2:PUSH BC PUSH DE CALL CLOSEIT ;close current extent. POP DE POP BC LD L,3 ;prepare for error. LD A,(STATUS) INC A JP Z,POSITN4 ;close error. LD HL,12 ;put desired extent into fcb now. ADD HL,DE LD (HL),C LD HL,14 ;and store extra extent byte 's2'. ADD HL,DE LD (HL),B CALL OPENIT ;try and get this extent. LD A,(STATUS) ;was it there? INC A JP NZ,POSITN3 POP BC ;no. can we create a new one (writing?). PUSH BC LD L,4 ;prepare for error. INC C JP Z,POSITN4 ;nope, reading unwritten space error. CALL GETEMPTY ;yes we can, try to find space. LD L,5 ;prepare for error. LD A,(STATUS) INC A JP Z,POSITN4 ;out of space? ; ; Normal return location. Clear error code and return. ; POSITN3:POP BC ;restore stack. XOR A ;and clear error code byte. JP SETSTAT ; ; Error. Set the 's2' byte to indicate this (why?). ; POSITN4:PUSH HL CALL GETS2 LD (HL),0C0H POP HL ; ; Return with error code (presently in L). ; POSITN5:POP BC LD A,L ;get error code. LD (STATUS),A JP SETS2B7 ; ; Read a random record. ; READRAN:LD C,0FFH ;set 'read' status. CALL POSITION ;position the file to proper record. CALL Z,RDSEQ1 ;and read it as usual (if no errors). RET ; ; Write to a random record. ; WRITERAN: LD C,0 ;set 'writing' flag. CALL POSITION ;position the file to proper record. CALL Z,WTSEQ1 ;and write as usual (if no errors). RET ; ; Compute the random record number. Enter with (HL) pointing ; to a fcb an (DE) contains a relative location of a record ; number. On exit, (C) contains the 'r0' byte, (B) the 'r1' ; byte, and (A) the 'r2' byte. ; ; On return, the zero flag is set if the record is within ; bounds. Otherwise, an overflow occured. ; COMPRAND: EX DE,HL ;save fcb pointer in (DE). ADD HL,DE ;compute relative position of record #. LD C,(HL) ;get record number into (BC). LD B,0 LD HL,12 ;now get extent. ADD HL,DE LD A,(HL) ;compute (BC)=(record #)+(extent)*128. RRCA ;move lower bit into bit 7. AND 80H ;and ignore all other bits. ADD A,C ;add to our record number. LD C,A LD A,0 ;take care of any carry. ADC A,B LD B,A LD A,(HL) ;now get the upper bits of extent into RRCA ;bit positions 0-3. AND 0FH ;and ignore all others. ADD A,B ;add this in to 'r1' byte. LD B,A LD HL,14 ;get the 's2' byte (extra extent). ADD HL,DE LD A,(HL) ADD A,A ;and shift it left 4 bits (bits 4-7). ADD A,A ADD A,A ADD A,A PUSH AF ;save carry flag (bit 0 of flag byte). ADD A,B ;now add extra extent into 'r1'. LD B,A PUSH AF ;and save carry (overflow byte 'r2'). POP HL ;bit 0 of (L) is the overflow indicator. LD A,L POP HL ;and same for first carry flag. OR L ;either one of these set? AND 01H ;only check the carry flags. RET ; ; Routine to setup the fcb (bytes 'r0', 'r1', 'r2') to ; reflect the last record used for a random (or other) file. ; This reads the directory and looks at all extents computing ; the largerst record number for each and keeping the maximum ; value only. Then 'r0', 'r1', and 'r2' will reflect this ; maximum record number. This is used to compute the space used ; by a random file. ; RANSIZE:LD C,12 ;look thru directory for first entry with CALL FINDFST ;this name. LD HL,(PARAMS) ;zero out the 'r0, r1, r2' bytes. LD DE,33 ADD HL,DE PUSH HL LD (HL),D ;note that (D)=0. INC HL LD (HL),D INC HL LD (HL),D RANSIZ1:CALL CKFILPOS ;is there an extent to process? JP Z,RANSIZ3 ;no, we are done. CALL FCB2HL ;set (HL) pointing to proper fcb in dir. LD DE,15 ;point to last record in extent. CALL COMPRAND ;and compute random parameters. POP HL PUSH HL ;now check these values against those LD E,A ;already in fcb. LD A,C ;the carry flag will be set if those SUB (HL) ;in the fcb represent a larger size than INC HL ;this extent does. LD A,B SBC A,(HL) INC HL LD A,E SBC A,(HL) JP C,RANSIZ2 LD (HL),E ;we found a larger (in size) extent. DEC HL ;stuff these values into fcb. LD (HL),B DEC HL LD (HL),C RANSIZ2:CALL FINDNXT ;now get the next extent. JP RANSIZ1 ;continue til all done. RANSIZ3:POP HL ;we are done, restore the stack and RET ;return. ; ; Function to return the random record position of a given ; file which has been read in sequential mode up to now. ; SETRAN: LD HL,(PARAMS) ;point to fcb. LD DE,32 ;and to last used record. CALL COMPRAND ;compute random position. LD HL,33 ;now stuff these values into fcb. ADD HL,DE LD (HL),C ;move 'r0'. INC HL LD (HL),B ;and 'r1'. INC HL LD (HL),A ;and lastly 'r2'. RET ; ; This routine select the drive specified in (ACTIVE) and ; update the login vector and bitmap table if this drive was ; not already active. ; LOGINDRV: LD HL,(LOGIN) ;get the login vector. LD A,(ACTIVE) ;get the default drive. LD C,A CALL SHIFTR ;position active bit for this drive PUSH HL ;into bit 0. EX DE,HL CALL SELECT ;select this drive. POP HL CALL Z,SLCTERR ;valid drive? LD A,L ;is this a newly activated drive? RRA RET C LD HL,(LOGIN) ;yes, update the login vector. LD C,L LD B,H CALL SETBIT LD (LOGIN),HL ;and save. JP BITMAP ;now update the bitmap. ; ; Function to set the active disk number. ; SETDSK: LD A,(EPARAM) ;get parameter passed and see if this LD HL,ACTIVE ;represents a change in drives. CP (HL) RET Z LD (HL),A ;yes it does, log it in. JP LOGINDRV ; ; This is the 'auto disk select' routine. The firsst byte ; of the fcb is examined for a drive specification. If non ; zero then the drive will be selected and loged in. ; AUTOSEL:LD A,0FFH ;say 'auto-select activated'. LD (AUTO),A LD HL,(PARAMS) ;get drive specified. LD A,(HL) AND 1FH ;look at lower 5 bits. DEC A ;adjust for (1=A, 2=B) etc. LD (EPARAM),A ;and save for the select routine. CP 1EH ;check for 'no change' condition. JP NC,AUTOSL1 ;yes, don't change. LD A,(ACTIVE) ;we must change, save currently active LD (OLDDRV),A ;drive. LD A,(HL) ;and save first byte of fcb also. LD (AUTOFLAG),A ;this must be non-zero. AND 0E0H ;whats this for (bits 6,7 are used for LD (HL),A ;something)? CALL SETDSK ;select and log in this drive. AUTOSL1:LD A,(USERNO) ;move user number into fcb. LD HL,(PARAMS) ;(* upper half of first byte *) OR (HL) LD (HL),A RET ;and return (all done). ; ; Function to return the current cp/m version number. ; GETVER: LD A,022H ;version 2.2 JP SETSTAT ; ; Function to reset the disk system. ; RSTDSK: LD HL,0 ;clear write protect status and log LD (WRTPRT),HL ;in vector. LD (LOGIN),HL XOR A ;select drive 'A'. LD (ACTIVE),A LD HL,TBUFF ;setup default dma address. LD (USERDMA),HL CALL DEFDMA JP LOGINDRV ;now log in drive 'A'. ; ; Function to open a specified file. ; OPENFIL:CALL CLEARS2 ;clear 's2' byte. CALL AUTOSEL ;select proper disk. JP OPENIT ;and open the file. ; ; Function to close a specified file. ; CLOSEFIL: CALL AUTOSEL ;select proper disk. JP CLOSEIT ;and close the file. ; ; Function to return the first occurence of a specified file ; name. If the first byte of the fcb is '?' then the name will ; not be checked (get the first entry no matter what). ; GETFST: LD C,0 ;prepare for special search. EX DE,HL LD A,(HL) ;is first byte a '?'? CP '?' JP Z,GETFST1 ;yes, just get very first entry (zero length match). CALL SETEXT ;get the extension byte from fcb. LD A,(HL) ;is it '?'? if yes, then we want CP '?' ;an entry with a specific 's2' byte. CALL NZ,CLEARS2 ;otherwise, look for a zero 's2' byte. CALL AUTOSEL ;select proper drive. LD C,15 ;compare bytes 0-14 in fcb (12&13 excluded). GETFST1:CALL FINDFST ;find an entry and then move it into JP MOVEDIR ;the users dma space. ; ; Function to return the next occurence of a file name. ; GETNXT: LD HL,(SAVEFCB) ;restore pointers. note that no LD (PARAMS),HL ;other dbos calls are allowed. CALL AUTOSEL ;no error will be returned, but the CALL FINDNXT ;results will be wrong. JP MOVEDIR ; ; Function to delete a file by name. ; DELFILE:CALL AUTOSEL ;select proper drive. CALL ERAFILE ;erase the file. JP STSTATUS ;set status and return. ; ; Function to execute a sequential read of the specified ; record number. ; READSEQ:CALL AUTOSEL ;select proper drive then read. JP RDSEQ ; ; Function to write the net sequential record. ; WRTSEQ: CALL AUTOSEL ;select proper drive then write. JP WTSEQ ; ; Create a file function. ; FCREATE:CALL CLEARS2 ;clear the 's2' byte on all creates. CALL AUTOSEL ;select proper drive and get the next JP GETEMPTY ;empty directory space. ; ; Function to rename a file. ; RENFILE:CALL AUTOSEL ;select proper drive and then switch CALL CHGNAMES ;file names. JP STSTATUS ; ; Function to return the login vector. ; GETLOG: LD HL,(LOGIN) JP GETPRM1 ; ; Function to return the current disk assignment. ; GETCRNT:LD A,(ACTIVE) JP SETSTAT ; ; Function to set the dma address. ; PUTDMA: EX DE,HL LD (USERDMA),HL ;save in our space and then get to JP DEFDMA ;the bios with this also. ; ; Function to return the allocation vector. ; GETALOC:LD HL,(ALOCVECT) JP GETPRM1 ; ; Function to return the read-only status vector. ; GETROV: LD HL,(WRTPRT) JP GETPRM1 ; ; Function to set the file attributes (read-only, system). ; SETATTR:CALL AUTOSEL ;select proper drive then save attributes. CALL SAVEATTR JP STSTATUS ; ; Function to return the address of the disk parameter block ; for the current drive. ; GETPARM:LD HL,(DISKPB) GETPRM1:LD (STATUS),HL RET ; ; Function to get or set the user number. If (E) was (FF) ; then this is a request to return the current user number. ; Else set the user number from (E). ; GETUSER:LD A,(EPARAM) ;get parameter. CP 0FFH ;get user number? JP NZ,SETUSER LD A,(USERNO) ;yes, just do it. JP SETSTAT SETUSER:AND 1FH ;no, we should set it instead. keep low LD (USERNO),A ;bits (0-4) only. RET ; ; Function to read a random record from a file. ; RDRANDOM: CALL AUTOSEL ;select proper drive and read. JP READRAN ; ; Function to compute the file size for random files. ; WTRANDOM: CALL AUTOSEL ;select proper drive and write. JP WRITERAN ; ; Function to compute the size of a random file. ; FILESIZE: CALL AUTOSEL ;select proper drive and check file length JP RANSIZE ; ; Function #37. This allows a program to log off any drives. ; On entry, set (DE) to contain a word with bits set for those ; drives that are to be logged off. The log-in vector and the ; write protect vector will be updated. This must be a M/PM ; special function. ; LOGOFF: LD HL,(PARAMS) ;get drives to log off. LD A,L ;for each bit that is set, we want CPL ;to clear that bit in (LOGIN) LD E,A ;and (WRTPRT). LD A,H CPL LD HL,(LOGIN) ;reset the login vector. AND H LD D,A LD A,L AND E LD E,A LD HL,(WRTPRT) EX DE,HL LD (LOGIN),HL ;and save. LD A,L ;now do the write protect vector. AND E LD L,A LD A,H AND D LD H,A LD (WRTPRT),HL ;and save. all done. RET ; ; Get here to return to the user. ; GOBACK: LD A,(AUTO) ;was auto select activated? OR A JP Z,GOBACK1 LD HL,(PARAMS) ;yes, but was a change made? LD (HL),0 ;(* reset first byte of fcb *) LD A,(AUTOFLAG) OR A JP Z,GOBACK1 LD (HL),A ;yes, reset first byte properly. LD A,(OLDDRV) ;and get the old drive and select it. LD (EPARAM),A CALL SETDSK GOBACK1:LD HL,(USRSTACK) ;reset the users stack pointer. LD SP,HL LD HL,(STATUS) ;get return status. LD A,L ;force version 1.4 compatability. LD B,H RET ;and go back to user. ; ; Function #40. This is a special entry to do random i/o. ; For the case where we are writing to unused disk space, this ; space will be zeroed out first. This must be a M/PM special ; purpose function, because why would any normal program even ; care about the previous contents of a sector about to be ; written over. ; WTSPECL:CALL AUTOSEL ;select proper drive. LD A,2 ;use special write mode. LD (MODE),A LD C,0 ;set write indicator. CALL POSITN1 ;position the file. CALL Z,WTSEQ1 ;and write (if no errors). RET ; ;************************************************************** ;* ;* BDOS data storage pool. ;* ;************************************************************** ; EMPTYFCB: DEFB 0E5H ;empty directory segment indicator. WRTPRT: DEFW 0 ;write protect status for all 16 drives. LOGIN: DEFW 0 ;drive active word (1 bit per drive). USERDMA:DEFW 080H ;user's dma address (defaults to 80h). ; ; Scratch areas from parameter block. ; SCRATCH1: DEFW 0 ;relative position within dir segment for file (0-3). SCRATCH2: DEFW 0 ;last selected track number. SCRATCH3: DEFW 0 ;last selected sector number. ; ; Disk storage areas from parameter block. ; DIRBUF: DEFW 0 ;address of directory buffer to use. DISKPB: DEFW 0 ;contains address of disk parameter block. CHKVECT:DEFW 0 ;address of check vector. ALOCVECT: DEFW 0 ;address of allocation vector (bit map). ; ; Parameter block returned from the bios. ; SECTORS:DEFW 0 ;sectors per track from bios. BLKSHFT:DEFB 0 ;block shift. BLKMASK:DEFB 0 ;block mask. EXTMASK:DEFB 0 ;extent mask. DSKSIZE:DEFW 0 ;disk size from bios (number of blocks-1). DIRSIZE:DEFW 0 ;directory size. ALLOC0: DEFW 0 ;storage for first bytes of bit map (dir space used). ALLOC1: DEFW 0 OFFSET: DEFW 0 ;first usable track number. XLATE: DEFW 0 ;sector translation table address. ; ; CLOSEFLG: DEFB 0 ;close flag (=0ffh is extent written ok). RDWRTFLG: DEFB 0 ;read/write flag (0ffh=read, 0=write). FNDSTAT:DEFB 0 ;filename found status (0=found first entry). MODE: DEFB 0 ;I/o mode select (0=random, 1=sequential, 2=special random). EPARAM: DEFB 0 ;storage for register (E) on entry to bdos. RELBLOCK: DEFB 0 ;relative position within fcb of block number written. COUNTER:DEFB 0 ;byte counter for directory name searches. SAVEFCB:DEFW 0,0 ;save space for address of fcb (for directory searches). BIGDISK:DEFB 0 ;if =0 then disk is > 256 blocks long. AUTO: DEFB 0 ;if non-zero, then auto select activated. OLDDRV: DEFB 0 ;on auto select, storage for previous drive. AUTOFLAG: DEFB 0 ;if non-zero, then auto select changed drives. SAVNXT: DEFB 0 ;storage for next record number to access. SAVEXT: DEFB 0 ;storage for extent number of file. SAVNREC:DEFW 0 ;storage for number of records in file. BLKNMBR:DEFW 0 ;block number (physical sector) used within a file or logical sect LOGSECT:DEFW 0 ;starting logical (128 byte) sector of block (physical sector). FCBPOS: DEFB 0 ;relative position within buffer for fcb of file of interest. FILEPOS:DEFW 0 ;files position within directory (0 to max entries -1). ; ; Disk directory buffer checksum bytes. One for each of the ; 16 possible drives. ; CKSUMTBL: DEFB 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ; ; Extra space ? ; DEFB 0,0,0,0 ; ;************************************************************** ;* ;* B I O S J U M P T A B L E ;* ;************************************************************** ; org 0F200H BOOT: JP 0 ;NOTE WE USE FAKE DESTINATIONS WBOOT: JP 0 CONST: JP 0 CONIN: JP 0 CONOUT: JP 0 LIST: JP 0 PUNCH: JP 0 READER: JP 0 HOME: JP 0 SELDSK: JP 0 SETTRK: JP 0 SETSEC: JP 0 SETDMA: JP 0 READ: JP 0 WRITE: JP 0 PRSTAT: JP 0 SECTRN: JP 0 ; ;* ;****************** E N D O F C P / M ***************** ;*