From acb@yoyo.cc.monash.edu.au Tue Dec 7 21:20:22 1993 Path: klaava!news.funet.fi!sunic!EU.net!howland.reston.ans.net!math.ohio-state.edu!uwm.edu!msuinfo!harbinger.cc.monash.edu.au!yoyo.cc.monash.edu.au!acb From: acb@yoyo.cc.monash.edu.au (Andrew Bulhak) Newsgroups: comp.sys.cbm Subject: Source code: copying tape fastloaders to disk Date: 7 Dec 1993 15:49:29 GMT Organization: People in a Position to Know, Inc. Lines: 283 Distribution: world Message-ID: <2e28m9$gc4@harbinger.cc.monash.edu.au> NNTP-Posting-Host: yoyo.cc.monash.edu.au X-Newsreader: TIN [version 1.2 PL1] OK, here's something I hacked up recently. There is no nice interface, but it works (and what's more, the business end has to fit into the tape buffer). This program will read any tape written in the turbo-loader format named ".DSL1.A" (which may or may not be named "DTAPE" as well; I think it's some freezer-cartridge format) and write the contents to a disk file (on device 8, drive 0, named "DCOPY.OUT"); then the program will reset the C64 (the program being copied overwrites part of the copying program). Since the UUEncoded binary is only a few lines, I have included it here as well. -- Andrew Bulhak | acb@yoyo.cc.monash.edu.au | "Parboiled are the lambs, that they may Monash Uni, Clayton, | not be so crunchy and hard to eat." Victoria, Australia | ----- SOURCE CODE FOLLOWS ----- processor 6502 ; dcopy.asm Program for reading/copying ; some fast-saved tape files ; Author: acb ; Commenced: 20-11-1993 ; Platform: Commodore 64 ; Tools used: dasm 2.12, running on Linux ; ; dcopy is a short program for copying tape files in the ; ".DSL1.A" (or "DTAPE"?) fast-loader format to disk. ; This program loads the turbo loader, positioning the tape, ; reads the bulk of the file (using direct tape I/O) and ; writes it to disk, in nice bite-sized chunks. include "kernel.inc" ; global defines lfs_in equ 32 lfs_out equ 33 dev_tape equ 1 dev_disk equ 8 chksum equ $90 ; address of XOR checksum work area org $0801 ; room for a BASIC stub ; BASIC stub goes here dc $0b, $08, $66, $19, $9E, $32, $30, $36, $31, 0, 0, 0 ;jmp start ; jump to the start start: ; set up what is necessary ; load the fastloader code, positioning tape as needed ; and allowing interesting stuff to be extracted lda #lfs_in ldx #dev_tape ldy #$00 ; relocate jsr setlfs lda #0 jsr setnam ; no name requested lda #$00 ; load, not verify ldx #$00 ldy #$80 ; load at $8000 (why not?) jsr load lda #$00 ; make screen black, for debugging purposes sta $d020 sta $d021 ; now copy all the code to where it shall be safe ; assume that it is less than one page in size ldx #relocatable sty $ad ldx #$34 stx $ae ldx #$03 stx $af ldy #$00 copy_loop1: lda ($ac),y sta ($ae),y ldx $ac iny cpy #<[reloc_end-reloc_start] bne copy_loop1 copy_done: jmp resume relocatable: rorg $0334 reloc_start: ; global variables go here outname: dc "@0:DCOPY.OUT" outname_end: dc 0 ; subroutines go here ; Subroutine getbyte, getbits ; ; Reads a byte/several bits from the tape in the fast-loader format ; ; Input: ; X: #$19 (to be put into a register) ; Y: # of bits (getbits only) ; ; Output: ; A: byte/bits retrieved getbyte: ldy #$08 ; byte = 8 bits, dig? getbits: getbit: lda #$10 inloop: bit $dc0d ; tape read IRQ triggered? beq inloop ; no, wait until it is so. lda $dd0d ; this stuff is copied verbatim stx $dd0f ; from ".DSL1.A"; at time of writing lsr ; I do not claim to fully understand it. lsr ; but I think $bd accumulates bits ror $bd inc $d020 ; do cheesy border flashing effect dey ; any more bits left to read bne getbit ; if so, read them lda $bd ; pick up our result ... rts ; ...and leave resume: ; load the fast-saved file and write it to disk ; initialise the hardware; heavy wizardry begins here sei ldx #$df ; cassette motor on stx $01 lda #$80 sta $dd06 ; timer B value = $0180 ldy #$01 sty $dd07 ldx #$00 ; the meaning of these three lines is unknown. ldy #$00 ; It probably has something to do with timing, nop ; though..... ldx #$19 stx $dd0f ; handle the magic values magic1: ldy #$09 ; read 9 bits jsr getbits cmp #$02 ; some magic code, I think..... bne magic1 magic2: jsr getbyte cmp #$02 ; this magic works differently (?) beq magic2 ; (or maybe its some kind of sync code?) cmp #$52 bne magic1 jsr getbyte cmp #$42 bne magic1 ; get file load address, size, etc. ; first, load address is acquired jsr getbyte sta $ac sta $c1 jsr getbyte sta $ad sta $c2 jsr getbyte sta $ae jsr getbyte sta $af ldy #$00 sta $90 ; clear checksum ; read the stuff into memory readloop: jsr getbyte sta ($ac),y ; write byte to memory eor $90 ; update checksum sta $90 ldy $ac iny sty $ac bne foo ldy $ad iny sty $ad foo: ldy $ad cpy $af bne readloop ldy $ac cpy $ae bne readloop ; read complete ; now check the checksum jsr getbyte eor $90 ; beq check_ok ; jmp $fce2 ; error! check_ok: sta $90 ; now write the disk file lda #$fe ; stop motor, switch BASIC ROM out sta $01 ; (Ghod help us if the program extends ; under the kernel ROM...) cli lda #lfs_out ldx #8 ldy #255 jsr setlfs lda #[outname_end-outname] ldx #outname jsr setnam lda #$c1 ; offset of start location ldx $ae ;inx ldy $af ;iny jsr save ; since vectors are munged and we have a fastloader routine ; sitting in memory, we might as well reset jmp $fce2 reloc_end: ----- END OF SOURCE CODE ----- begin 644 dcopy.prg M 0@+"&89GC(P-C$ "I(*(!H @NO^I ""]_ZD H@"@@"#5_ZD C2#0C2'0 MHDR&K* (A*VB-(:NH@.&KZ L:R1KJ:LR,#$T/5,70- ,#I$0T]062Y/550 MH BI$"P-W/#[K0W=C@_=2DIFO>X@T(C0Z:6]8'BBWX8!J8"-!MV@ 8P'W:( MH #JHAF.#]V@"2!# \D"T/<@00/) O#YR5+0["!! \E"T.4@00.%K(7!($$# MA:V%PB!! X6N($$#A:^@ (60($$#D:Q%D(60I*S(A*S0!:2MR(2MI*W$K]#E MI*S$KM#?($$#19"%D*G^A0%8J2&B"*#_(+K_J0RB-* #(+W_J<&FKJ2O(-C_ #3.+\ end