; ______ _ _ _____ ______
; | ____(_) | |_ _| / / __ \
; | |__ _| | ___ | | / / | | |
; | __| | | |/ _ \ | | / /| | | |
; | | | | | __/ _| |_ / / | |__| |
; |_| |_|_|\___| |_____/_/ \____/
; File IO implementation
; FILE ( s-addr s-len buf-addr -- )
; Builds a PAB in the buffer whose address is passed as buf_addr using the data
; in the string represented by s_addr and s_len.
; For example:
; FBUF: PRINTER
; S" PIO.CR DV80O" PRINTER FILE
; The above builds a PAB in the buffer called PRINTER which references the PIO
; device. Subsequent file IO words that wish to send data to the PIO shall use
; the buffer name to reference it:
; e.g.
; PRINTER #OPEN DROP ( open PIO and drop success/fail flag)
; S" HELLO WORLD" PRINTER #PUT DROP
; ( write HELLO WORLD to the PIO and drop success/fail flag)
;
; Internally, FILE builds a PAB in the buffer which will be used by #OPEN and
; all file IO words.
; Word 0 of the reserved memory is used to point to the actual PAB in VDP
; memory. Enough space should be reserved (with ALLOT) in the buffer to hold the
; PAB and the filename.
;
; The string which specifies the file name and file characteristics is defined
; as below.
; The filename *must* come first followed by a space character. After that, the
; file options can be specified in any order.
;
; File Options:
; F=Fixed - Fixed record type
; V=Variable - Variable record type
;
; D=Display - Display data type
; L=InternaL - Internal data type
;
; U=Update - Update file mode
; O=Output - Output file mode
; I=Input - Inoput file mode
; A=Append - Append file mode
;
; S=Sequential - Sequential file type
; R=Relative - Relative file type
;
; Note that Internal type files require L
; this is because I is used to specify INPUT
_file clr r8 ; zero the record length accumulator
mov *stack+,r10 ; pop buffer address from stack
; zero the first 10 bytes of the alloted buffer
; (holds the PAB data - no need to zero the filename length byte or the
; file, as they'll be populated later)
mov r10,r13 ; copy buffer address
li r1,10 ; number of bytes to clear
_ficll clr *r13+ ; clear two bytes in buffer
dect r1 ; decrement counter
jne _ficll ; repeat if not finished
; transfer filename to PAB...
clr r6 ; byte ops
mov @2(stack),r0 ; address of string in pad
mov r10,r1 ; copy buffer address
ai r1,12 ; point to 1st filename byte
clr r2 ; filename length
tfnl movb *r0+,r6 ; get a character
dec *stack ; decrement string length
ci r6,' '*256 ; space?
jeq wfnlb ; jump if yes
movb r6,*r1+ ; otherwise copy the byte
inc r2 ; increment length count
jmp tfnl ; and repeat
; write filename length byte...
wfnlb swpb r2 ; get length in high byte
movb r2,@11(r10) ; move length byte into length byte position
; process file options...
fdochr movb *r0+,r6 ; get a character
dec *stack ; end of string?
jlt fdone ; jump if yes
ci r6,' '*256 ; is it a space?
jeq fdochr ; if yes then ignore it
ci r6,'9'*256 ; found a digit?
jle fdodig ; if so then do digit
; the option is a character.
; process it against the allowed list of characters
li r7,foopts ; pointer to options list
li r13,10 ; 10 options in the list
fnxtop cb r6,*r7 ; compare a character
jeq ffopt ; jump if match detected
inc r7 ; move to next charater in list
dec r13 ; decrement count
jne fnxtop ; check next option
jmp fdochr ; check next character
; process numeric digit
fdodig mov r8,r9 ; copy accumulator
sla r8,3 ; multiply accumulator by 8
sla r9,1 ; multiply copy by 2
a r9,r8 ; add them - we just did a multiply by 10
; (MPY needs consecutive registers, and sometimes its just too much
; like hard work, know what I mean?)
srl r6,8 ; shift byte into low byte
ai r6,-48 ; remove ascii offset
a r6,r8 ; add to accumulator
clr r6 ; byte ops
jmp fdochr ; process next character
; set file option...
ffopt ai r7,-20 ; point to appropriate mask byte (the bits
; to reset)
movb @3(r10),r1 ; get flag byte from PAB
szcb *r7,r1 ; reset appropriate bit(s)
ai r7,10 ; point to bits table (the bits to set)
socb *r7,r1 ; set appropriate bit(s)
movb r1,@3(r10) ; write it back
ai r7,10 ; restore pointer
jmp fdochr ; process next character in the string
fdone swpb r8 ; get record length in msb
movb r8,@6(r10) ; move it into the pab
; dect stack ; pop length
; dect stack ; pop address
c *stack+,*stack+ ; pop length & address
jmp fexit
fomask byte >10,>10 ; F & V mask
byte >08,>08 ; D & I mask
byte >06,>06,>06,>06 ; U O I & A masks
byte >01,>01 ; S & R masks
bitmsk byte >00,>10 ; F & V bits
byte >00,>08 ; D & I bits
byte >00,>02,>04,>06 ; U O I & A bits
byte >00,>01 ; S & R bits
foopts text 'FVDLUOIASR' ; file options (L=internaL)
; #OPEN ( file_addr -- t|f )
; Opens a file with the file name and attributes specified in the buffer
; starting at file_addr.
; The buffer (actually a PAB) is set-up with FILE.
; E.g. FBUF: SERIAL
; S" RS232.BA=9600 DV80SO" SERIAL FILE
; SERIAL #OPEN
; The above shall attempt to open the serial port for output as a Display
; Variable 80 type file.
;
; #OPEN leaves a FALSE on the stack if the file was opened sucessfully.
; If the file could not be opened then it leaves a TRUE on the stack.
; This allows easy trapping with ABORT" as shown below:
; SERIAL #OPEN ABORT" Could not open serial port"
;
; In the event of a file error, IOERR can be read to get the DSR error code.
; If IOERR returns -1 (>FFFF) then this means that no free file IO slots were
; found. A maximum of 3 open files is supported (2 if block files are also to
; be used). Note that block files are immediately closed after they are accessed
; for either reading or writing, so 3 generic file io streams are available
; when no blocks files are being used.
; find a free file slot...
_fopen li r0,falloc ; address of file allocation table
li r2,3 ; three slots
nxtslt mov *r0,r1 ; first slot address
jgt foend ; if msb is not set then the slot is empty
inct r0 ; otherwise move to next slot address
dec r2 ; and try it
jne nxtslt
; no free slots... sorry, no can do...
seto @errnum ; set ioerr to -1 (no available files)
seto *stack ; leave a TRUE on the stack
b @retB0
; ok, the slot is free...
foend mov *stack,r10 ; cpu pab address
mov r1,*r10 ; store vdp address of the free PAB in word
; 0 of CPU RAM PAB
mov r1,r2 ; copy the vdp address
ori r2,>8000 ; set its most-sig bit to indicate this slot
; is in use
mov r2,*r0 ; write it back falloc table
ai r1,40 ; record buffer in vdp is 40 bytes after PAB
mov r1,@4(r10) ; store it in bytes 2 & 3 of the PAB
ai r1,-40 ; restore r1 to point to PAB address in VDP
; transfer the PAB in CPU RAM to the appropriate place in VDP
mov r1,r0 ; get in r0 for VMBW
mov r0,r8 ; keep a copy
mov r10,r1 ; source address
inct r1 ; move past word 0 in CPU PAB (vdp address
; pointer)
li r2,40 ; byte count
bl @_vmbw0 ; write it to VDP
ai r8,9 ; adjust vdp address copy to point to
; filename length byte
mov r8,@namptr ; store in >8356 as per DSR requirements
blwp @dsrlnk ; call dos
data 8 ; disk op parameter, level 3 command
jeq _foerr ; jump if an error
clr *stack ; set top of stack to FALSE (success)
clr @errnum ; clear io error
jmp fexit
; the file could not be opened
_foerr srl r0,8 ; move error code to lower byte
mov r0,@errnum ; set disk io error number
seto *stack ; set true flag (failure)
jmp fexit
; #CLOSE ( fid -- )
; closes a file
; Where a file is opened thus: S" DSK1.README DV80IS" #OPEN MYFILE
; the following will close the same file: MYFILE #CLOSE
_fclos bl @dodcmd
data close*256
; now reset the pab pointer in the file allocation table...
; r13 holds the vdp address of the start of the pab
li r1,falloc ; address of file allocation table
li r2,3 ; 3 entries in the table
_fclop mov *r1,r6 ; get an entry
andi r6,>7fff ; remove msb
c r6,r13 ; found the entry?
jeq _fcfnd ; jump if yes
inct r1 ; try next word
dec r2 ; decrement counter
jne _fclop ; repeat if not finished
_fcxit jmp fexit
_fcfnd mov r13,*r1 ; move address (with msb reset) back into
; file allocation table