; ZIP.Z80
;
; Create ZIP archives for CPM
; J.G.Harston 06-Nov-2000
;
; Vers 100 -- 31-Aug-2023 -- J.G.Harston
; Rewritten for ZMac. Can be assembled with ZMAC with:
;
; ZMAC -o ZIP.COM ZIP100.Z80
;
; Vers 101 -- 08-Dec-2023 -- Lars Nelson
; Fixed a problem where the computed CRC for some but
; not all files was not being written into the Local
; File Header especially on CP/M 2.2 and compatible
; systems. This caused a problem for CP/M unzip
; programs because they use the information in the
; Local File Header to extract files. Lack of a valid
; CRC causes the unzip programs to skip the file.
; Note, central directory was correct so on PCs or
; Macs all files could be extracted. nAdded
; ability to get file modification date from CP/M Plus
; and CP/M 2.2 using routines from DSLIB and ZSLIB. This
; necessitated making the code relocatable.
;
; To do: add DU: support. Add ability to add file to a zip
; file.
;
; Production:
; File is now best assembled and linked with Alex Hawley's ZMAC
; & ZML as opposed to some other assembler named ZMAC. Set SLR
; true below. Libraries DSLIB.REL, ZSLIB.REL & SYSLIB.REL are
; required to be in the default directory
;
; zmac zip101
; zml zip101
;
; Z80ASM & SLRNK can also be used. If want to use SLR .REL
; files instead of Microsoft .REL files, add an 'S' to the end
; of the library names, i.e. use DSLIBS.REL, ZSLIBSREL &
; SYSLIBS.REL.
;
Vers equ 101
VersDD equ 08
VersMM equ 12
VersYY equ 2023
;
false equ 0
true equ not false
;
SLR equ true ; set true if using SLR assembler
;
bdos equ 0005h
FCB1 equ 005Ch
FCB2 equ 006Ch
FCB1PTR equ FCB1+32 ; Output pointer bytes
DMA equ 0080h
CCPSIZE equ 0800h
NAMELEN equ 12 ; "DFILENAMEEXT" in FCB
@FT EQU 9 ; File type
;
bd_conout equ 2
bd_string equ 9
bd_open equ 15
bd_close equ 16
bd_sfirst equ 17
bd_snext equ 18
bd_delete equ 19
bd_read equ 20
bd_write equ 21
bd_make equ 22
bd_setdma equ 26
bd_rndrd equ 33
bd_rndwr equ 34
bd_getsize equ 35
bd_setptr equ 36
;
; These appear to be high memory ROM routines on Mr. Harston's
; CP/M machine so they should be avoided.
;PR1HEX equ 0FFAAh
;PR2HEX equ 0FFADh
;OSNEWL equ 0FFE7h
;
global ENVPTR,$MEMRY
;
.request dslib
extrn timini,DOSTYP,DOSVER,TIMTYP,@BDOS,GSTAMP
extrn U2MTIM
;
; .request zslib
; extrn getstp,gstpcp
;
.request syslib ; sylib usually last
;
cseg ; to read in .rel library routines
jp Start
db 'Z3ENV',1 ; Z3 signiture
ENVPTR: dw 0
;
; Code run once, could be overwritten
Start: ld (OldStack),sp ; save old stack
ld hl,(bdos+1) ; start of BDOS
ld de,-CCPSIZE ; allow for CCP
add hl,de
ld sp,hl ; put stack at top of memory
ld de,(ENVPTR) ; check for z-system
ld a,d
or e
jr nz,strt
xor a ; not running zsystem
strt: ld (zflag),a ; clear flag
call timini ; check for datestamping support
; Global variables returned:
; DOSTYP ='S'=>ZSDOS, 'D'=>Datestamper & '3'=>CP/M Plus.
; 0=>no datestamping
; DOSVER has version number, 22=>CP/M 2.2 and
; compatiblle. 11 for ZSDOS
;
; force zip extention if no extension given on command line
LD A,(FCB1+@FT) ; See if any filetype was specified
CP ' ' ;
JR NZ,SKPZIP ; If so, leave it as is
LD HL,'PI' ; Else inject a ".ZIP" extension
LD (FCB1+@FT+1),HL ;
LD A,'Z' ;
LD (FCB1+@FT+0),A ;
SKPZIP:
call Start0 ; call main program
Exit: ld sp,(OldStack) ; recover stack
ret
Start0: ld hl,ZeroStart
ld de,ZeroStart+1
ld bc,ZeroEnd-ZeroStart-1
ld (hl),0
ldir ; Zero workspace
ld a,(FCB2+1)
cp 32
jp z,ZipSyntax ; No filenames
; ld hl,0081h ; hl=>start of line, zero terminated
; note: documentation claims the command line at &0080 is unterminated, but
; DRCCP terminates the line with &00, as do other CCPs that follow the same
; practice.
ld hl,0080h ; command buffer
ld l,(hl) ; get length
set 7,l ; point after end of line
inc hl
ld (hl),0 ; put terminator in
ld l,81h ; hl=>start of line
OptLp1: ld bc,0 ; b=0, options
ld a,(hl) ; get character
inc hl
cp ' '
jr z,OptLp1 ; skip spaces
jr c,OptDone ; end of command line
cp '['
jr z,Opts ; start of options string
Optlp3: ld a,(hl)
inc hl
cp ' '
jr z,OptLp1
jr nc,OptLp3 ; skip filename
jr OptDone ; end of command line
Opts: ld a,(hl)
inc hl
cp ' '
jr z,OptLp1 ; another filename
cp '?'
jp z,ZipSyntax ; ZIP [?] - display usage
and 05Fh ; upper case
jr z,OptDone ; end of command line
cp ']'
jr nc,OptDone ; end of options
or b
ld b,a
jr Opts
OptDone:
ld (Options-1),bc ; note options, also zero Pass
; bit 1 = [O]verwrite
; bit 4 = [Q]uiet
;
; Check for output file
BIT 1,B
JR Z,DeleteOk ; [O]verwrite off
LD DE,FCB1
LD C,bd_delete ; Delete any existing file
CALL bdos
DeleteOk:
; GRRRRR Any call to bd_make kills FindFirst and FindNext
; So, have to build up a list of source files first, and then
; do the copying.
; ARAGH!G!HG!I^%!&^$!^%#!!
;
LD DE,($MEMRY) ; DE=>heap to make list of names
LD C,bd_sfirst
ScanLoop:
PUSH BC
PUSH DE
LD DE,FCB2
CALL bdos ; Search directory
POP DE
POP BC
INC A
JR Z,ScanDone ; No more files
ADD A,A
ADD A,A
ADD A,A
ADD A,A
ADD A,A ; Multiply by 32 to point to entry
ADD A,DMA-32 ; Point to start of filename
LD L,A
LD H,DMA/256 ; HL=>entry
LD A,(FCB2+0) ; Source drive
LD (HL),A ; Put into file list
LD BC,NAMELEN ; DRIVE+FILENAME+EXT
LDIR ; Copy name to heap
LD HL,-0180h ; 128buffer+128buffer+128stack
ADD HL,SP ; HL=SP-&180
SBC HL,DE ; HL=SP-&180-heaptop
JP C,ErrOutOfMem
LD C,bd_snext
JR ScanLoop
ScanDone:
DEC A
LD (DE),A ; &FF terminator
INC DE
LD (OutputBuffer),DE
LD HL,128
ADD HL,DE
LD (InputBuffer),HL
;
; Open output file
ld hl,FCB2
ld de,FCB2+1
ld bc,19
ld (hl),0
ldir ; clear out FCB!
LD DE,FCB1
LD C,bd_sfirst ; Test for output file
CALL bdos
INC A
JP NZ,ErrFileExists
LD DE,FCB1
LD C,bd_make ; Create output file
CALL bdos
INC A
JP Z,ErrDirFull
ld de,FCB1
ld c,bd_open ; open output file
call bdos
ld de,DMA
ld c,bd_setdma
call bdos
ld de,FCB1
ld c,bd_rndwr ; write anything don't inc CR
; Can no longer use FCB2 as it is now the metadata for FCB1
;
; Now go through list of names
FileStart:
LD HL,($MEMRY) ; HL=>heap to make list of names
FileLoop:
LD A,(HL) ; HL=>filename
INC A
JP Z,FilesDone ; No more files
LD DE,FCB3
LD BC,NAMELEN
LDIR ; Copy name to FCB3
PUSH HL
LD HL,Header+0 ; Clear header workspace
LD DE,Header+1
LD BC,HeaderEnd-Header-1
LD (HL),0
LDIR
if SLR
ld hl,'KP' ; PK little endian
else
LD HL,'PK'
endif
LD A,(Pass)
AND A
JR Z,FileData ; Pass=0, data segment
LD (DirSig+0),HL ; Directory signiture
LD HL,0201h
LD (DirSig+2),HL
LD HL,DirName ; HL=>name store in header
JR FileDataGo
FileData:
LD (HdrSig+0),HL
LD HL,0403h ; Put data signiture in
LD (HdrSig+2),HL
LD HL,NumFiles
INC (HL)
JP Z,ShutTooManyFiles
LD HL,HdrName ; HL=>name store in header
FileDataGo:
; Move filename in FCB3 to Local Header, print it and get
; length for Local Header in BC. Note original code needed
; FCB3 to be far enough away from record boundry and
; could not be made relocatable. Thus, it has been
; rewritten so that absolute addresses not needed at
; assembly time.
LD DE,FCB3+1 ; DE=>name in FCB3
; LD BC,0 ; BC= Filename length
ld b,11 ; up to 11 chars to process
ld c,0 ; filename length
NameLoop:
; LD A,E
ld a,b ; characters output so far
; SUB FCB3 AND 255 ; doesn't work in CSEG since
; ; FCB3 is in DSEG
; CP 12
cp 3 ; finished with name?
; JR Z,NameDone ; All 12 chars done
; CP 9
CALL Z,NameDot ; If yes, Insert dot & start on ext.
LD A,(DE)
INC DE
; CP ' '
; JR Z,NameLoop ; Truncate spaces
CALL NamePut
djnz NameLoop
jr NameDone
NameDot:
LD A,(DE)
CP '!'
LD A,'.'
RET C ; Don't output dot if no extension
NamePut:
cp ' '
ret z ; remove whitespace
LD (HL),A ; Store it in header
CALL PRCHAR ; Print character
INC HL
; INC BC
inc c
RET
NameDone:
LD (HdrNameSz),BC ; Store name size
LD DE,FCB3
LD C,bd_getsize ; get file size
CALL bdos
LD DE,(FCB3PTR+0)
LD HL,(FCB3PTR+2)
LD E,0
SRL H
RR L
RR D
RR E ; HLDE=records*128
LD (HdrFSize+0),DE
LD (HdrSize+0),DE
LD (HdrFSize+2),HL
LD (HdrSize+2),HL
; CALL PR2HEX
; EX DE,HL
; CALL PR2HEX
CALL SavePTR ; save output PTR
CALL SaveHeader ; save header, also set CRC=&FFFFFFFF
;
XOR A
LD (FCB3+12),A ; ex=0 for open
LD DE,FCB3
LD C,bd_open ; open input file
CALL bdos
INC A
JP Z,ShutInputFailed
;
; Now that input file is open, get the modify date/time stamp.
; For CP/M Plus, the date stamp is 4 bytes. 2 bytes for days
; since 1978 and 2 bytes of bcd Hours and minutes. For CP/M
; 2.2 /w Datestamper or ZSDOS, the stamp is 5 bytes of
; bcd year, month, day, hour, & minutes. ZIP files
; use the MS-DOS 32 bit packed binary format. Time is 16-bits
; with Bits [15:11] = hour, Bits [10:5] = minutes and
; Bits [4:0] = seconds/2 (not displayed). Date is 16-bits
; with Bits [15:9] = year - 1980, Bits [8:5] = month and
; Bits [4:0] = day. Datestamp is stored little endian so time
; comes first then date. The DSLIB routine GSTAMP will return
; either CP/M Plus or Datestamper stamps in Datestamp format,
; while U2MTIM will convert Datestamper to MS-DOS format .
; (Note ZSDOS can use CP/M style date stamping but returns
; stamp in Datestamper format).
; QPM, DOSPlus or Z80DOS stamping are not supported at this
; time.
;
; copy FCB because CP/M Plus returns date in the FCB
ld hl,FCB3
ld de,FCB4
ld bc,36
ldir
ld de,FCB4
ld hl,dsbuf
call gstamp
jr z,NoDS ; no dsatestamp found
; convert packed bcd modify time to MS-DOS fornat. Note:
; CP/M date stamps have no seconds.
ld de,dsbuf+10 ; point to modify stamp
ld hl,HdrTime ; put MS-DOS time in header
call U2MTIM ; convert stamp to MS-DOS
NoDS:
LD HL,0
LD (FCB3PTR+0),HL ; Set PTR to zero
LD (FCB3PTR+2),HL
LD A,(Options)
BIT 4,A
JR NZ,CopyLoop ; [Q]uiet
LD DE,MsgAdding
LD C,bd_string
CALL bdos
;
; copy data
CopyLoop:
LD DE,(InputBuffer)
LD C,bd_setdma
CALL bdos
LD DE,FCB3
LD C,bd_read
CALL bdos ; read 128-byte record
AND A
JR NZ,CopyEOF ; end of input file
LD HL,128
LD DE,(InputBuffer)
CALL SaveData ; write 128 bytes to output
JR CopyLoop
CopyEOF:
; CALL PRHEX
LD DE,FCB3
LD C,bd_close ; close input file
CALL bdos
; LD HL,(HdrCRC+2)
; CALL PR2HEX
; LD HL,(HdrCRC+0)
; CALL PR2HEX
; Update header
CALL RestorePTR ; move back to saved header
CALL SaveHeader ; save updated header, also CRC=CRC EOR &FFFFFFFF
CALL RestorePTR ; back to end of file
;
CALL CRLF
POP HL
JP FileLoop
FilesDone:
; At the end of pass zero, all files with local
; headers have been written. In the next pass through
; the file, we need to build the central directory by
; rewinding the output file, adding file location info
; and writing expanded header info to the central
; directory. This again requires hoping back and forth
; from the central directory and the local headers as
; we progrss down the output file.
LD A,16
LD (Options),A ; On second pass, set to [Q]uiet
LD A,(Pass)
AND A ; end of pass zer0?
CALL Z,SavePTR ; Save pointer to end of data/start of directory
CALL Z,ConvertPTR ; Convert saved PTR to absolute offset
; for use in central directory
INC A
LD (Pass),A ; increment pass flag
CP 2
JP C,FileStart ; Do two passes only
; Central directory now written so we need to Create END of
; Central Direcotry Header
if SLR
ld hl,'KP' ; Put signiture in
else
LD HL,'PK' ; Put signiture in
endif
LD (EOFSig+0),HL
LD HL,0605h
LD (EOFSig+2),HL
LD HL,0
LD (EOFDiskThis),HL
LD (EOFDiskStart),HL
LD (EOFCommentSz),HL
LD HL,(NumFiles)
LD H,0
LD (EOFFilesThis),HL
LD (EOFFilesTotal),HL
LD HL,(SavedPTR+0)
LD (EOFDirOffset+0),HL
LD HL,(SavedPTR+2)
LD (EOFDirOffset+2),HL
CALL SavePTR
CALL ConvertPTR
AND A
LD HL,(SavedPTR+0)
LD DE,(EOFDirOffset+0)
SBC HL,DE
LD (EOFDirSize+0),HL
LD HL,(SavedPTR+2)
LD DE,(EOFDirOffset+2)
SBC HL,DE
LD (EOFDirSize+2),HL
LD HL,EOFEnd-Header
CALL SaveEOF ; Save EOF segment
JR CloseOutput
ClosePad:
CALL PutZero
CloseOutput:
LD A,(OutputOffset)
AND A
JR NZ,ClosePad ; Pad to end of sector
ShutOutput:
LD DE,FCB1
LD C,bd_close ; Close output file
JP bdos
SaveHeader:
LD HL,HdrCRC
LD B,4
SaveCRC:
LD A,(HL) ; CRC = CRC EOR &FFFFFFFF
CPL
LD (HL),A
INC HL
DJNZ SaveCRC
LD BC,(HdrNameSz) ; Length of name field
LD HL,HdrName-Header
ADD HL,BC ; HL=length of header
LD A,(Pass)
AND A
JR Z,SaveEOF ; Pass=0, data header
LD BC,16 ; dir header is 16 bytes longer
ADD HL,BC
LD DE,Directory
SCF ; CS=Header, don't build CRC
JR SaveDataGo
SaveEOF:
LD DE,Header
SCF ; CS=Header, don't build CRC
JR SaveDataGo
;
; HL=count, DE=start of data, FCB1=output file, CC=update CRC
SaveData:
EXX
LD DE,(HdrCRC+0) ; Incoming CRC
LD HL,(HdrCRC+2)
EXX
AND A ; CC=Data, build CRC
SaveDataGo:
PUSH AF
SaveDataLp:
POP AF ; Get Carry flag back
PUSH AF
LD A,(DE)
JR C,SaveData2 ; Don't update CRC
; The following code updates the CRC with the byte in A
PUSH AF ; Save the byte
EXX
XOR E ; XOR byte into CRC bottom byte
LD B,8 ; Prepare to rotate 8 bits
CRClp: SRL H ; Rotate CRC
RR L
RR D
RRA
JR NC,CRCclear ; b0 was zero
LD E,A ; Put CRC low byte back into E
LD A,H
XOR 0EDh ; CRC=CRC XOR &EDB88320, ZIP polynomic
LD H,A
LD A,L
XOR 0B8h
LD L,A
LD A,D
XOR 083h
LD D,A
LD A,E
XOR 020h ; And get CRC low byte back into A
CRCclear:
DJNZ CRClp ; Loop for 8 bits
LD E,A ; Put CRC low byte back into E
EXX
LD A,(Pass)
AND A
JR NZ,SaveData0 ; Not data segment, don't output
POP AF ; Get the byte back
CALL PutByte ; Output data byte
JR SaveData3
SaveData0:
POP AF ; Get the byte back
JR SaveData3
;
SaveData2:
CALL PutByte ; Output header byte
SaveData3:
INC DE
DEC HL
LD A,H
OR L
JR NZ,SaveDataLp
POP AF ; Get Carry back
RET C ; Don't update CRC
EXX
LD (HdrCRC+0),DE ; Outgoing CRC
LD (HdrCRC+2),HL
EXX
RET
;
; ConvertPTR -- convert the saved random record field
; to number of bytes from the beginning of the
; output file. Four byte result saved at SavedPTR.
; Uses A, HL & DE. Preserves CPU Flags
;
ConvertPTR:
PUSH AF ; preserve flag
LD A,(FCB1Saved+4)
LD DE,(FCB1Saved+0)
LD HL,(FCB1Saved+2)
ADD A,A
LD E,A
SRL H ; shift HLDE right
RR L
RR D
RR E ; HLDE=records*128+Offset
LD (SavedPTR+0),DE ; save result
LD (SavedPTR+2),HL
POP AF ; restore flags
RET
; Save PTR - Save the current location in the zip file for later
; return. Location is saved by using the random record field of
; the FCB. BDOS function 36 is used set the field. This three
; byte field is then saved for later use by RestorPTR & ConverPTR.
; Preserves AF & HL.
;
SavePTR:
PUSH AF ; preserve AF & HL
PUSH HL
LD DE,FCB1
LD C,bd_setptr
CALL bdos ; Set randpm record field
LD HL,(FCB1PTR+0) ;save CR & R0
LD (FCB1Saved+0),HL
LD HL,(FCB1PTR+2) ; save R1 & R2
LD (FCB1Saved+2),HL
LD A,(OutputOffset)
LD (FCB1Saved+4),A
POP HL
POP AF
RET
;
; RestorePTR - Move to location in zip file saved by SavePTR.
; Also saves the current location and moves file access to the
; location using a random read. Since random read doesn't
; change the record pointer, subsequent sequential reads or
; writes occur at the same location. Preserves DE & HL.
;
RestorePTR:
PUSH HL
PUSH DE
LD DE,FCB1
LD C,bd_setptr
CALL bdos ; Set randpm record field
LD HL,(FCB1PTR+0) ; push current random record &
PUSH HL ; OutputOffset on stack
LD HL,(FCB1PTR+2)
PUSH HL
LD A,(OutputOffset)
PUSH AF
or a
jr z,RPTR0
ld de,(OutputBuffer) ; random write OutputBuffer
ld c,bd_setdma ; if offset not zero
call bdos
ld de,FCB1
ld c,bd_rndwr
call bdos
RPTR0:
LD HL,(FCB1Saved+0) ; get saved random record field
LD (FCB1PTR+0),HL ; and put it into the FCB
LD HL,(FCB1Saved+2)
LD (FCB1PTR+2),HL
ld de,(OutputBuffer) ; fill buffer
ld c,bd_setdma
call bdos
LD DE,FCB1
LD C,bd_rndrd ; using random read
CALL bdos
LD A,(FCB1Saved+4)
LD (OutputOffset),A ; and set offset within buffer
POP AF
LD (FCB1Saved+4),A
POP HL ; save current location
LD (FCB1Saved+2),HL
POP HL
LD (FCB1Saved+0),HL
POP DE
POP HL
RET
FlushSave:
PUSH HL
PUSH DE
JR PutByteSave
PutZero:
XOR A
PutByte:
PUSH HL
PUSH DE
LD DE,(OutputOffset)
LD D,0
LD HL,(OutputBuffer)
ADD HL,DE
LD (HL),A
LD A,E
INC A
LD (OutputOffset),A
CP 080h
JR C,PutByteDone ; Buffer not full yet
XOR A
LD (OutputOffset),A
PutByteSave:
LD DE,(OutputBuffer)
LD C,bd_setdma
CALL bdos
LD DE,FCB1
LD C,bd_write
CALL bdos
PutByteDone:
POP DE
POP HL
RET
CRLF: LD A,10
CALL PRCHAR
LD A,13
;
; Output A, save all registers
PRCHAR: PUSH BC
PUSH DE
PUSH HL
LD E,A
LD A,(Options)
BIT 4,A
JR NZ,PRDONE ; [Q]uiet
LD C,bd_conout
CALL bdos
PRDONE: POP HL
POP DE
POP BC
RET
ShutInputFailed:
CALL ShutOutput
LD DE,MsgInputFailed
JR MsgAbort
ErrOutOfMem:
LD DE,MsgOutOfMem
JR MsgAbort
ShutTooManyFiles:
CALL ShutOutput
LD DE,MsgTooManyFiles
JR MsgAbort
ErrFileExists:
LD DE,MsgFileExists
JR MsgAbort
ShutDirFull:
CALL ShutOutput
ErrDirFull:
LD DE,MsgDirFull
JR MsgAbort
ShutDiskFull:
CALL ShutOutput
ErrDiskFull:
LD DE,MsgDiskFull
JR MsgAbort
ZipSyntax:
LD DE,MsgSyntax
MsgAbort:
LD C,bd_string
CALL bdos
JP Exit
; dseg
; Initialised data
MsgSyntax:
DEFM "ZIP v"
DEFB '0'+((Vers / 100) MOD 10),'.'
DEFB '0'+((Vers / 10) MOD 10),'0'+(Vers MOD 10)," - JGH "
; convert VersDD, VersMM, VersYY to date string in dd-mmm-yyyy format
defb '0'+(VersDD / 10),'0'+(VersDD mod 10),'-'
if (VersMM lt 1) or (VersMM gt 12)
defb 'xxx'
else
if VersMM eq 1
defb 'Jan'
endif
if VersMM eq 2
defb 'Feb'
endif
if VersMM eq 3
defb 'Mar'
endif
if VersMM eq 4
defb 'Apr'
endif
if VersMM eq 5
defb 'May'
endif
if VersMM eq 6
defb 'Jun'
endif
if VersMM eq 7
defb 'Jul'
endif
if VersMM eq 8
defb 'Aug'
endif
if VersMM eq 9
defb 'Sep'
endif
if VersMM eq 10
defb 'Oct'
endif
if VersMM eq 11
defb 'Nov'
endif
if VersMM eq 12
defb 'Dec'
endif
endif
defb '-','0'+((VersYY / 1000) mod 10),'0'+((VersYY / 100) mod 10)
defb '0'+((VersYY / 10) mod 10),'0'+(VersYY mod 10)
DEFM 10,13
DEFM "Usage: ZIP <zipfile>name[.zip] <afn> [/OQ]",10,13
db 'Options:',13,10
db ' Q - Quiet',13,10
db ' O - Overwrite existing file',13,10
db ' / - Print this helP',13,10
DEFM "Eg: ZIP OUT.ZIP *.COM",10,13
DEFM " ZIP ALLFILES.ZIP *.*",10,13,"$"
MsgAdding:
DEFM " -- adding","$"
MsgFileExists:
DEFM "ZipFile already exists",10,13,"$"
MsgDiskFull:
DEFM "Disk full",10,13,"$"
MsgDirFull:
DEFM "Dir. full",10,13,"$"
MsgOutOfMem:
DEFM "Out of memory",10,13,"$"
MsgTooManyFiles:
DEFM "Too many input files",10,13,"$"
MsgInputFailed:
DEFM 10,13,"Couldn't open input file",10,13,"$"
$MEMRY: DS 2
dseg
; Uninitialised data
OldStack: DEFW 0000h ; Also end of saved data
ZeroStart: ; Start of area to be zeroed
Pass: DEFB 0 ; 0=local list, 1=directory, 2=EOF
Options: DEFB 0 ; command line options i.e. O and/or Q
NumFiles: DEFB 0 ; Number of entries
;FileOffset: DS 4 ; Offset to data segment entry
InputOffset: DEFB 0 ; Index into input buffer
OutputOffset: DEFB 0 ; Index into output buffer
InputBuffer: DEFW 0000h ; Input buffer
OutputBuffer: DEFW 0000h ; Output buffer
ZeroEnd: ; End of area to be zeroed on startup
FCB3: DEFS 36 ; Input file control block
FCB4: ds 36 ; Copy FCB3 here
FCB3PTR EQU FCB3+32 ; Input file pointer bytes
FCB1SaveOffset DEFS 1 ; Saved output offset
FCB1Saved DEFS 5 ; Saved output PTR
SavedPTR DEFS 4 ; Saved absolute PTR to output file
dsbuf ds 128 ; date stamp buffer
zflag ds 1 ; Zsystem Flag
;
; Central directory overlaps local header
Directory:
DirSig: DS 2 ; Header signature PK,&01,&02
DirMadeBy EQU DirSig+4; Version made by (&0000)
;
; Local header
Header:
HdrSig: DS 4 ; Header signature PK,&03,&04
HdrVersion: DS 2 ; Version needed to extract (&0000)
HdrFlags: DS 2 ; General purpose bit flag (&0000)
HdrMethod: DS 2 ; Compression method
HdrTime: DS 2 ; Modification time (&0000)
HdrDate: DS 2 ; Modification date (&0000)
HdrCRC: DS 4 ; 32-bit CRC
HdrSize: DS 4 ; Compressed size
HdrFSize: DS 4 ; Uncompressed size
HdrNameSz: DS 2 ; Filename length
HdrExtraSz: DS 2 ; Extra field length (&0000)
HdrName: DS 0 ; Filename, overlapping next data
;
; Central directory also has:
DirCommentSz: DS 2 ; Comment length (&0000)
DirDisk: DS 2 ; Starting disk number (&0000)
DirAttrsIn: DS 2 ; Internal file attributes (&0000)
DirAttrsEx: DS 4 ; External file attributes (&0000)
DirOffset: DS 4 ; Relative offset of local header
DirName: DS 12 ; Filename, CP/M are max "12345678.123"
HeaderEnd:
;
; EOF header:
EOFSig EQU Header+0 ; Header signiture 4 bytes PK,&05,&06
EOFDiskThis EQU Header+4 ; Number of this disk 2 bytes (&0000)
EOFDiskStart EQU Header+6 ; Number of start disk 2 bytes (&0000)
EOFFilesThis EQU Header+8 ; Number of entries 2 bytes (NumFiles)
EOFFilesTotal EQU Header+10 ; Total num. entries 2 bytes (NumFiles)
EOFDirSize EQU Header+12 ; Size of central dir 4 bytes (OffsetEOF-OffsetDir)
EOFDirOffset EQU Header+16 ; Offset to central dir 4 bytes (OffsetDir)
EOFCommentSz EQU Header+20 ; Comment length 2 bytes (&0000)
EOFEnd EQU Header+22
;
; This is a heap of all data used
; List of filenames read from source in 12-byte FCB format
; &FF terminator
; 128-byte output buffer
; 128-byte input buffer
; ...
; stack
; Top of memory at BDOS-&800