mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-12-26 11:30:12 +00:00
ootw: loader: squeeze back down into 3 pages
now prompts you to switch disks, but doesn't have enough room to give you more info (like which disk)
This commit is contained in:
Vince Weaver
parent
615e6cf36b
commit
587495a4d7
@ -80,7 +80,7 @@ Development notes:
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Ootw Memory map:
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00 zero page
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01 stack
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02 ????
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02 disk-filename (30 bytes)
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03 nibble table/disk data
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04-07 GR page0
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08-0b GR page1
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@ -96,7 +96,7 @@ Ootw Memory map:
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Intro Memory map:
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00 zero page
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01 stack
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02 ????
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02 disk filename (30 bytes)
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03 nibble table/disk data
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04-07 GR page0
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08-0b GR page1
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@ -163,13 +163,13 @@ ootw2 memory squeeze:
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LOADER=1400 TITLE=1.75k = 7 pages = load at $D00
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2560 max size allowed
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L2 Memory map:
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00 zero page
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01 stack
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02 ????
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02 disk-filename
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03 nibble table/disk data
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04-07 GR page0
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08-0b GR page1
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@ -177,6 +177,7 @@ L2 Memory map:
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10-13 offscreen data2
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14-16 loader
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17+ game
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c0-cf I/O
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d0-ff ROM
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263
ootw/loader.s
263
ootw/loader.s
@ -42,6 +42,7 @@ filbuf = $3D6 ; filbuf: .res 4 ; = bit2tbl+86
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; process
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FILENAME = $280
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;===================================================
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;===================================================
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@ -110,13 +111,20 @@ load_ending:
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sta OUTH
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; fallthrough
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;===================================================
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;===================================================
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; SET UP DOS3.3 FILENAME
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;===================================================
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;===================================================
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opendir_filename:
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; clear out the filename with $A0 (space)
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lda #<filename
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lda #<FILENAME
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sta namlo
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lda #>filename
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lda #>FILENAME
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sta namhi
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ldy #29
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@ -145,10 +153,10 @@ copy_filename_done:
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jmp which_load_loop
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; filename to open is 30-character Apple text, must be padded with space ($A0)
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filename:
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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;filename:
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; .byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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; .byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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; .byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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intro_filename:
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.byte "INTRO",0
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@ -160,6 +168,13 @@ ootw_filename:
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.byte "OOTW_C",0,0,0
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;===================================================
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;===================================================
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; INIT (build nibble table)
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;===================================================
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;===================================================
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;unhook DOS and build nibble table
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init:
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@ -185,6 +200,7 @@ init:
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clc
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adc #8
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sta mlsmc02+1
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sta mlsmc07+1
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; c0e9
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clc
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@ -230,9 +246,57 @@ L3: inx ; increment x x=4, a=0f
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rts
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;===========================
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; opendir
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;===========================
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;===================================================
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;===================================================
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; file not found
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;===================================================
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;===================================================
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file_not_found:
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mlsmc07:lda $c0e8 ; turn off drive motor?
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jsr HOME
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ldy #0
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lda #<disk_string
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sta OUTL
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lda #>disk_string
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sta OUTH
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quick_print:
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lda (OUTL),Y
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beq quick_print_done
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jsr COUT1
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iny
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jmp quick_print
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quick_print_done:
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; rts
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; jsr quick_print
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fnf_keypress:
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lda KEYPRESS
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bpl fnf_keypress
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bit KEYRESET
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jmp which_load_loop
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disk_string:
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.byte "INSERT OTHER DISK, PRESS RETURN",0
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;===================================================
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;===================================================
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; OPENDIR: actually load the file
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;===================================================
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;===================================================
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; turn on drive and read volume table of contents
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opendir:
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@ -248,7 +312,7 @@ firstent:
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; lock if entry not found
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entry_not_found:
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beq entry_not_found
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beq file_not_found
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; read directory sector
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@ -401,8 +465,6 @@ L6:
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; restore current address
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readdone:
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pla
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; sta adrhi
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; pla
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sta adrlo ; code originally had this backwards
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pla
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sta adrhi
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@ -613,183 +675,6 @@ L26:
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bne copy_cur
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.if 0
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;==============================
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; old code
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; [re-]read sector
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re_read_addr:
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jsr readadr
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repeat_until_right_sector:
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cmp reqsec
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bne re_read_addr
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;==========================
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; read sector data
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;==========================
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;
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readdata:
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mlsmc07:
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ldy $c0ec ; read data until valid
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bpl readdata
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find_D5:
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cpy #$d5 ; if not D5, repeat
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bne readdata
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find_AA:
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mlsmc08:
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ldy $c0ec ; read data until valid, should be AA
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bpl find_AA
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cpy #$aa ; we need Y=#$AA later
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bne find_D5
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find_AD:
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mlsmc09:lda $c0ec ; read data until high bit set (valid)
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bpl find_AD
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eor #$ad ; should match $ad
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bne * ; lock if didn't find $ad (failure)
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L12:
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mlsmc0A:ldx $c0ec ; read data until high bit set (valid)
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bpl L12
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eor nibtbl-$80, x
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sta bit2tbl-$aa, y
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iny
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bne L12
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L13:
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mlsmc0B:ldx $c0ec ; read data until high bit set (valid)
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bpl L13
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eor nibtbl-$80, x
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sta (adrlo), y ; the real address
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iny
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cpy secsize
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bne L13
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ldy #0
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L14:
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ldx #$a9
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L15:
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inx
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beq L14
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lda (adrlo), y
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lsr bit2tbl-$aa, x
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rol
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lsr bit2tbl-$aa, x
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rol
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sta (adrlo), y
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iny
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cpy secsize
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bne L15
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rts
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; no tricks here, just the regular stuff
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;=================
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; readadr -- read address field
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;=================
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; Find address field, put track in cutrk, sector in tmpsec
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readadr:
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mlsmc0C:lda $c0ec ; read data until we find a $D5
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bpl readadr
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adr_d5:
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cmp #$d5
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bne readadr
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adr_aa:
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mlsmc0D:lda $c0ec ; read data until we find a $AA
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bpl adr_aa
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cmp #$aa
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bne adr_d5
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adr_96:
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mlsmc0E:lda $c0ec ; read data until we find a $96
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bpl adr_96
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cmp #$96
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bne adr_d5
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ldy #3 ; three?
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; first read volume/volume
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; then track/track
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; then sector/sector?
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adr_read_two_bytes:
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sta curtrk ; store out current track
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tax
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L20:
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mlsmc0F:lda $c0ec ; read until full value
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bpl L20
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rol
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sta tmpsec
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L21:
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mlsmc10:lda $c0ec ; read until full value
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bpl L21 ; sector value is (v1<<1)&v2????
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and tmpsec
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dey ; loop 3 times
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bne adr_read_two_bytes
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seekret:
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rts ; return
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;================
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; SEEK
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;================
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; current track in curtrk
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; desired track in phase
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seek:
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asl curtrk ; multiply by 2
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asl phase ; multiply by 2
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lda #0
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sta step
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copy_cur:
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lda curtrk ; load current track
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sta tmptrk ; store as temptrk
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sec ; calc current-desired
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sbc phase
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beq seekret ; if they match, we are done!
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bcs seek_neg ; if negative, skip ahead
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eor #$ff ; ones-complement the distance
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inc curtrk ; increment current (make it 2s comp?)
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bcc L114 ; skip ahead
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seek_neg:
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adc #$fe
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dec curtrk
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L114:
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cmp step
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bcc L115
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lda step
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L115:
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cmp #8
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bcs L116
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tay
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sec
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L116:
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lda curtrk
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ldx step1, y
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bne L118
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L117:
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clc
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lda tmptrk
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ldx step2, y
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L118:
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stx tmpsec
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and #3
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rol
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tax
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mlsmc11:sta $c0e0, x
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L119:
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ldx #$13
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L120:
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dex
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bne L120
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dec tmpsec
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bne L119
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lsr
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bcs L117
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inc step
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bne copy_cur
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.endif
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step1: .byte $01, $30, $28, $24, $20, $1e, $1d, $1c
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step2: .byte $70, $2c, $26, $22, $1f, $1e, $1d, $1c
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847
ootw/loader2.s
847
ootw/loader2.s
@ -1,847 +0,0 @@
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; Loader for OOTW
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; the BASIC program sets $05 with which thing to load
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nibtbl = $300 ; nothing uses the bottom 128 bytes of $300, do they?
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bit2tbl = $380 ; bit2tbl: .res 86 ; = nibtbl+128
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filbuf = $3D6 ; filbuf: .res 4 ; = bit2tbl+86
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; read any file slot 6 version
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; based on FASTLD6 and RTS copyright (c) Peter Ferrie 2011-2013,2018
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; modified to assembled with ca64 -- vmw
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; added code to patch it to run from current disk slot -- vmw
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WHICH_LOAD = $05 ; thing to load
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adrlo = $26 ; constant from boot prom
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adrhi = $27 ; constant from boot prom
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tmpsec = $3c ; constant from boot prom
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reqsec = $3d ; constant from boot prom
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sizelo = $44
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sizehi = $45
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secsize = $46
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TEMPY = $fa
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namlo = $fb
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namhi = $fc
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step = $fd ; state for stepper motor
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tmptrk = $fe ; temporary copy of current track
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phase = $ff ; current phase for /seek
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OUTL = $fe ; for picking filename
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OUTH = $ff
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dirbuf = $c00
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; note, don't put this immediately below
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; the value being read as destaddr-4
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; is temporarily overwritten during read
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; process
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; note also, can't load file bigger than $8000 (32k) in size?
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; seems to break things?
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start:
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jsr init ; unhook DOS, init nibble table
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;======================
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which_load_loop:
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ldy WHICH_LOAD
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lda filenames_low,Y
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sta OUTL
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lda filenames_high,Y
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sta OUTH
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opendir_filename:
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; clear out the filename with $A0 (space)
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lda #<filename
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sta namlo
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lda #>filename
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sta namhi
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ldy #29
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wipe_filename_loop:
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lda #$A0
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sta (namlo),Y
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dey
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bpl wipe_filename_loop
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ldy #0
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copy_filename_loop:
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lda (OUTL),Y
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beq copy_filename_done
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ora #$80
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sta (namlo),Y
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iny
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bne copy_filename_loop
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copy_filename_done:
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jsr opendir ; open and read entire file into memory
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jsr $1700 ; jump to common entry point
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; hope they updated the WHICH_LOAD value
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jmp which_load_loop
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; filename to open is 30-character Apple text, must be padded with space ($A0)
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filename:
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
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filenames_low:
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.byte <intro_filename
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.byte <ootw_c1_filename
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.byte <ootw_c2_filename
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.byte <ootw_c3_filename
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.byte <ootw_c4_filename
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.byte <ootw_c5_filename
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.byte <ootw_c6_filename
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.byte <ootw_c7_filename
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.byte <ootw_c8_filename
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.byte <ootw_c9_filename
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.byte <ootw_c10_filename
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.byte <ootw_c11_filename
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.byte <ootw_c12_filename
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.byte <ootw_c13_filename
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.byte <ootw_c14_filename
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.byte <ootw_c15_filename
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.byte <ending_filename
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filenames_high:
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.byte >intro_filename
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.byte >ootw_c1_filename
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.byte >ootw_c2_filename
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.byte >ootw_c3_filename
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.byte >ootw_c4_filename
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.byte >ootw_c5_filename
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.byte >ootw_c6_filename
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.byte >ootw_c7_filename
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.byte >ootw_c8_filename
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.byte >ootw_c9_filename
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.byte >ootw_c10_filename
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.byte >ootw_c11_filename
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.byte >ootw_c12_filename
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.byte >ootw_c13_filename
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.byte >ootw_c14_filename
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.byte >ootw_c15_filename
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.byte >ending_filename
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intro_filename:
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.byte 0
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ootw_c1_filename:
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.byte 0
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ootw_c2_filename:
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.byte 0
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ootw_c3_filename:
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.byte 0
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ootw_c4_filename:
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.byte 0
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ootw_c5_filename:
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.byte 0
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ootw_c6_filename:
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.byte "OOTW_C6",0
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ootw_c7_filename:
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.byte "OOTW_C7",0
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ootw_c8_filename:
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.byte "OOTW_C8",0
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ootw_c9_filename:
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.byte "OOTW_9",0
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ootw_c10_filename:
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.byte "OOTW_C10",0
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ootw_c11_filename:
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.byte "OOTW_C11",0
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ootw_c12_filename:
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.byte "OOTW_C12",0
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ootw_c13_filename:
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.byte "OOTW_C13",0
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ootw_c14_filename:
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.byte "OOTW_C14",0
|
||||
|
||||
ootw_c15_filename:
|
||||
.byte "OOTW_C15",0
|
||||
|
||||
ending_filename:
|
||||
.byte "ENDING",0
|
||||
|
||||
|
||||
|
||||
;unhook DOS and build nibble table
|
||||
|
||||
init:
|
||||
; patch to use current drive
|
||||
|
||||
; locate input paramater list
|
||||
jsr $3E3
|
||||
; result is in A:Y
|
||||
sta $FF
|
||||
sty $FE
|
||||
ldy #1
|
||||
lda ($FE),y
|
||||
|
||||
; list+1 should have slot<<8
|
||||
|
||||
|
||||
ora #$80 ; add in $80
|
||||
|
||||
; c0e0
|
||||
sta mlsmc06+1
|
||||
|
||||
; c0e8
|
||||
clc
|
||||
adc #8
|
||||
sta mlsmc02+1
|
||||
|
||||
; c0e9
|
||||
clc
|
||||
adc #1
|
||||
sta mlsmc01+1
|
||||
|
||||
; c0ec
|
||||
clc
|
||||
adc #3
|
||||
sta mlsmc03+1
|
||||
sta mlsmc04+1
|
||||
sta mlsmc05+1
|
||||
|
||||
jsr $fe93 ; clear COUT
|
||||
jsr $fe89 ; clear KEYIN
|
||||
|
||||
;========================
|
||||
; Create nibble table
|
||||
; Note: the table starts 16 bytes in, and is sparse
|
||||
; so it doesn't entirely look like the DOS33 table at
|
||||
|
||||
ldy #0
|
||||
ldx #3
|
||||
L1: stx $3c ; store tempx (3?)
|
||||
txa ; a=x (a=3)
|
||||
asl ; a*=2 (a=6)
|
||||
bit $3c ; a&tempx, set N/V (a=6)
|
||||
beq L3 ; if 0, skip to L3
|
||||
ora $3c ; a|=tempx (a=7)
|
||||
eor #$ff ; a=~a (a=f8)
|
||||
and #$7e ; a&=0x7e 0111 1110 (a=78)
|
||||
L2: bcs L3 ; this set way back at asl??
|
||||
lsr ; a>>1 a=3c c=0
|
||||
; a=1e c=0
|
||||
; a=0f c=0
|
||||
; a=07 c=1
|
||||
bne L2 ; if a!=0 goto l2
|
||||
tya ; if a==0, a=y
|
||||
sta nibtbl, x ; write out to table
|
||||
iny ; increment y
|
||||
L3: inx ; increment x x=4, a=0f
|
||||
bpl L1 ; loop while high bit not set
|
||||
|
||||
rts
|
||||
|
||||
;===========================
|
||||
; opendir
|
||||
;===========================
|
||||
|
||||
; turn on drive and read volume table of contents
|
||||
opendir:
|
||||
mlsmc01:lda $c0e9 ; turn slot#6 drive on
|
||||
ldx #0
|
||||
stx adrlo ; zero out adrlo
|
||||
stx secsize ; zero out secsize
|
||||
lda #$11 ; a=$11 (VTOC)
|
||||
jsr readdirsec
|
||||
firstent:
|
||||
|
||||
lda dirbuf+1
|
||||
|
||||
; lock if entry not found
|
||||
entry_not_found:
|
||||
beq entry_not_found
|
||||
|
||||
; read directory sector
|
||||
|
||||
ldx dirbuf+2
|
||||
jsr seekread1
|
||||
ldy #7 ;number of directory entries in a sector
|
||||
ldx #$2b ;offset of filename in directory entry
|
||||
nextent:
|
||||
tya
|
||||
pha ; was **phy**
|
||||
txa
|
||||
pha ; was **phx**
|
||||
ldy #$1d
|
||||
|
||||
; match name backwards (slower but smaller)
|
||||
|
||||
L4:
|
||||
lda (namlo), y
|
||||
cmp dirbuf, x
|
||||
beq foundname
|
||||
pla
|
||||
|
||||
; move to next directory in this block, if possible
|
||||
|
||||
clc
|
||||
adc #$23
|
||||
tax
|
||||
pla
|
||||
tay ; was **ply**
|
||||
dey
|
||||
bne nextent
|
||||
beq firstent ; was **bra**
|
||||
|
||||
foundname:
|
||||
dex
|
||||
dey
|
||||
bpl L4
|
||||
pla
|
||||
tay ; was **ply**
|
||||
pla
|
||||
|
||||
; read track/sector list
|
||||
|
||||
lda dirbuf-32, y
|
||||
ldx dirbuf-31, y
|
||||
jsr seekread1
|
||||
|
||||
; read load offset and length info only, initially
|
||||
|
||||
lda #<filbuf
|
||||
sta adrlo
|
||||
lda #4
|
||||
sta secsize
|
||||
lda dirbuf+12
|
||||
ldx dirbuf+13
|
||||
ldy #>filbuf
|
||||
jsr seekread
|
||||
|
||||
; reduce load offset by 4, to account for offset and length
|
||||
|
||||
sec
|
||||
lda filbuf
|
||||
sbc #4
|
||||
sta adrlo
|
||||
|
||||
lda filbuf+1
|
||||
sbc #0
|
||||
sta adrhi
|
||||
|
||||
; save on stack bytes that will be overwritten by extra read
|
||||
|
||||
ldy #3
|
||||
L5:
|
||||
lda (adrlo), y
|
||||
pha
|
||||
dey
|
||||
bpl L5
|
||||
|
||||
lda adrhi
|
||||
pha
|
||||
lda adrlo
|
||||
pha
|
||||
|
||||
; increase load size by 4, to account for offst and length
|
||||
|
||||
lda filbuf+2
|
||||
adc #3
|
||||
sta sizelo
|
||||
sta secsize
|
||||
|
||||
lda filbuf+3
|
||||
adc #0
|
||||
sta sizehi
|
||||
beq readfirst
|
||||
lda #0 ; was **stz secsize**
|
||||
sta secsize
|
||||
|
||||
readfirst:
|
||||
ldy #$0c
|
||||
|
||||
; read a file sector
|
||||
|
||||
readnext:
|
||||
tya
|
||||
pha
|
||||
lda dirbuf, y ; A = track
|
||||
ldx dirbuf+1, y ; x = sector
|
||||
jsr seekread1
|
||||
pla
|
||||
tay
|
||||
|
||||
; if low count is non-zero then we are done
|
||||
; (can happen only for partial last block)
|
||||
|
||||
lda secsize
|
||||
bne readdone
|
||||
|
||||
; continue if more than $100 bytes left
|
||||
|
||||
dec sizehi
|
||||
bne L6
|
||||
|
||||
; set read size to min(length, $100)
|
||||
|
||||
lda sizelo
|
||||
beq readdone
|
||||
sta secsize
|
||||
L6:
|
||||
inc adrhi
|
||||
iny
|
||||
iny
|
||||
bne readnext
|
||||
|
||||
; save current address for after t/s read
|
||||
|
||||
lda adrhi
|
||||
pha
|
||||
lda adrlo
|
||||
pha
|
||||
lda #0
|
||||
sta adrlo ; was **stz adrlo**
|
||||
|
||||
; read next track/sector sector
|
||||
|
||||
lda dirbuf+1
|
||||
ldx dirbuf+2
|
||||
jsr readdirsec
|
||||
clc
|
||||
|
||||
; restore current address
|
||||
readdone:
|
||||
pla
|
||||
; sta adrhi
|
||||
; pla
|
||||
sta adrlo ; code originally had this backwards
|
||||
pla
|
||||
sta adrhi
|
||||
bcc readfirst
|
||||
|
||||
mlsmc02:lda $c0e8
|
||||
|
||||
; restore from stack bytes that were overwritten by extra read
|
||||
|
||||
ldx #3
|
||||
ldy #0
|
||||
L7:
|
||||
pla
|
||||
sta (adrlo), y
|
||||
iny
|
||||
dex
|
||||
bpl L7
|
||||
rts
|
||||
|
||||
|
||||
;======================
|
||||
; readdirsec
|
||||
;======================
|
||||
; a = track?
|
||||
; x = sector?
|
||||
readdirsec:
|
||||
ldy #>dirbuf
|
||||
seekread:
|
||||
sty adrhi
|
||||
seekread1:
|
||||
sta phase
|
||||
lda sectbl, x
|
||||
sta reqsec
|
||||
jsr readadr
|
||||
|
||||
; if track does not match, then seek
|
||||
|
||||
cpx phase
|
||||
beq checksec
|
||||
jsr seek
|
||||
|
||||
|
||||
;=========================================
|
||||
; re merge in with qkumba's recent changes
|
||||
; to fix seek problem?
|
||||
;=========================================
|
||||
|
||||
; [re-]read sector
|
||||
|
||||
re_read_addr:
|
||||
jsr readadr
|
||||
checksec:
|
||||
cmp reqsec
|
||||
bne re_read_addr
|
||||
|
||||
;=========================
|
||||
; read sector data
|
||||
;=========================
|
||||
|
||||
readdata:
|
||||
jsr readd5aa
|
||||
eor #$ad ; zero A if match
|
||||
bne re_read_addr
|
||||
|
||||
L12:
|
||||
mlsmc03:ldx $c0ec ; read until valid data (high bit set)
|
||||
bpl L12
|
||||
eor nibtbl-$80, x
|
||||
sta bit2tbl-$aa, y
|
||||
iny
|
||||
bne L12
|
||||
L13:
|
||||
mlsmc04:ldx $c0ec ; read until valid data (high bit set)
|
||||
bpl L13
|
||||
eor nibtbl-$80, x
|
||||
sta (adrlo), y ; the real address
|
||||
iny
|
||||
cpy secsize
|
||||
bne L13
|
||||
ldy #0
|
||||
L14:
|
||||
ldx #$a9
|
||||
L15:
|
||||
inx
|
||||
beq L14
|
||||
lda (adrlo), y
|
||||
lsr bit2tbl-$aa, x
|
||||
rol
|
||||
lsr bit2tbl-$aa, x
|
||||
rol
|
||||
sta (adrlo), y
|
||||
iny
|
||||
cpy secsize
|
||||
bne L15
|
||||
rts
|
||||
|
||||
; no tricks here, just the regular stuff
|
||||
|
||||
;=======================
|
||||
; readaddr -- read the address field
|
||||
;=======================
|
||||
; Find address field, put track in cutrk, sector in tmpsec
|
||||
|
||||
readadr:
|
||||
jsr readd5aa
|
||||
cmp #$96
|
||||
bne readadr
|
||||
ldy #3 ; three?
|
||||
; first read volume/volume
|
||||
; then track/track
|
||||
; then sector/sector?
|
||||
adr_read_two_bytes:
|
||||
tax
|
||||
jsr readnib
|
||||
rol
|
||||
sta tmpsec
|
||||
jsr readnib
|
||||
and tmpsec
|
||||
dey
|
||||
bne adr_read_two_bytes
|
||||
rts
|
||||
|
||||
;========================
|
||||
; make sure we see the $D5 $AA pattern
|
||||
|
||||
readd5aa:
|
||||
L16:
|
||||
jsr readnib
|
||||
L17:
|
||||
cmp #$d5
|
||||
bne L16
|
||||
jsr readnib
|
||||
cmp #$aa
|
||||
bne L17
|
||||
tay ; we need Y=#$AA later
|
||||
|
||||
readnib:
|
||||
mlsmc05:lda $c0ec ; read until valid (high bit set)
|
||||
bpl readnib
|
||||
|
||||
seekret:
|
||||
rts
|
||||
|
||||
;=====================
|
||||
; SEEK
|
||||
;=====================
|
||||
; current track in X?
|
||||
; desired track in phase
|
||||
|
||||
seek:
|
||||
ldy #0
|
||||
sty step
|
||||
asl phase ; multiply by two
|
||||
txa ; current track?
|
||||
asl ; mul by two
|
||||
copy_cur:
|
||||
tax
|
||||
sta tmptrk
|
||||
sec
|
||||
sbc phase
|
||||
beq L22
|
||||
bcs L18
|
||||
eor #$ff
|
||||
inx
|
||||
bcc L19
|
||||
L18:
|
||||
sbc #1
|
||||
dex
|
||||
L19:
|
||||
cmp step
|
||||
bcc L20
|
||||
lda step
|
||||
L20:
|
||||
cmp #8
|
||||
bcs L21
|
||||
tay
|
||||
sec
|
||||
L21:
|
||||
txa
|
||||
pha
|
||||
ldx step1, y
|
||||
L22:
|
||||
php
|
||||
bne L24
|
||||
L23:
|
||||
clc
|
||||
lda tmptrk
|
||||
ldx step2, y
|
||||
L24:
|
||||
stx tmpsec
|
||||
and #3
|
||||
rol
|
||||
tax
|
||||
lsr
|
||||
mlsmc06:lda $c0e0, x
|
||||
L25:
|
||||
ldx #$12
|
||||
L26:
|
||||
dex
|
||||
bpl L26
|
||||
dec tmpsec
|
||||
bne L25
|
||||
bcs L23
|
||||
plp
|
||||
beq seekret
|
||||
pla
|
||||
inc step
|
||||
bne copy_cur
|
||||
|
||||
|
||||
.if 0
|
||||
;==============================
|
||||
; old code
|
||||
|
||||
|
||||
; [re-]read sector
|
||||
|
||||
re_read_addr:
|
||||
jsr readadr
|
||||
|
||||
repeat_until_right_sector:
|
||||
cmp reqsec
|
||||
bne re_read_addr
|
||||
|
||||
;==========================
|
||||
; read sector data
|
||||
;==========================
|
||||
;
|
||||
|
||||
readdata:
|
||||
mlsmc07:
|
||||
ldy $c0ec ; read data until valid
|
||||
bpl readdata
|
||||
find_D5:
|
||||
cpy #$d5 ; if not D5, repeat
|
||||
bne readdata
|
||||
find_AA:
|
||||
mlsmc08:
|
||||
ldy $c0ec ; read data until valid, should be AA
|
||||
bpl find_AA
|
||||
cpy #$aa ; we need Y=#$AA later
|
||||
bne find_D5
|
||||
find_AD:
|
||||
mlsmc09:lda $c0ec ; read data until high bit set (valid)
|
||||
bpl find_AD
|
||||
eor #$ad ; should match $ad
|
||||
bne * ; lock if didn't find $ad (failure)
|
||||
L12:
|
||||
mlsmc0A:ldx $c0ec ; read data until high bit set (valid)
|
||||
bpl L12
|
||||
eor nibtbl-$80, x
|
||||
sta bit2tbl-$aa, y
|
||||
iny
|
||||
bne L12
|
||||
L13:
|
||||
mlsmc0B:ldx $c0ec ; read data until high bit set (valid)
|
||||
bpl L13
|
||||
eor nibtbl-$80, x
|
||||
sta (adrlo), y ; the real address
|
||||
iny
|
||||
cpy secsize
|
||||
bne L13
|
||||
ldy #0
|
||||
L14:
|
||||
ldx #$a9
|
||||
L15:
|
||||
inx
|
||||
beq L14
|
||||
lda (adrlo), y
|
||||
lsr bit2tbl-$aa, x
|
||||
rol
|
||||
lsr bit2tbl-$aa, x
|
||||
rol
|
||||
sta (adrlo), y
|
||||
iny
|
||||
cpy secsize
|
||||
bne L15
|
||||
rts
|
||||
|
||||
; no tricks here, just the regular stuff
|
||||
|
||||
;=================
|
||||
; readadr -- read address field
|
||||
;=================
|
||||
; Find address field, put track in cutrk, sector in tmpsec
|
||||
readadr:
|
||||
mlsmc0C:lda $c0ec ; read data until we find a $D5
|
||||
bpl readadr
|
||||
adr_d5:
|
||||
cmp #$d5
|
||||
bne readadr
|
||||
|
||||
adr_aa:
|
||||
mlsmc0D:lda $c0ec ; read data until we find a $AA
|
||||
bpl adr_aa
|
||||
cmp #$aa
|
||||
bne adr_d5
|
||||
|
||||
adr_96:
|
||||
mlsmc0E:lda $c0ec ; read data until we find a $96
|
||||
bpl adr_96
|
||||
cmp #$96
|
||||
bne adr_d5
|
||||
|
||||
ldy #3 ; three?
|
||||
; first read volume/volume
|
||||
; then track/track
|
||||
; then sector/sector?
|
||||
adr_read_two_bytes:
|
||||
sta curtrk ; store out current track
|
||||
tax
|
||||
L20:
|
||||
mlsmc0F:lda $c0ec ; read until full value
|
||||
bpl L20
|
||||
rol
|
||||
sta tmpsec
|
||||
L21:
|
||||
mlsmc10:lda $c0ec ; read until full value
|
||||
bpl L21 ; sector value is (v1<<1)&v2????
|
||||
and tmpsec
|
||||
dey ; loop 3 times
|
||||
bne adr_read_two_bytes
|
||||
|
||||
seekret:
|
||||
rts ; return
|
||||
|
||||
;================
|
||||
; SEEK
|
||||
;================
|
||||
; current track in curtrk
|
||||
; desired track in phase
|
||||
|
||||
seek:
|
||||
asl curtrk ; multiply by 2
|
||||
asl phase ; multiply by 2
|
||||
lda #0
|
||||
sta step
|
||||
copy_cur:
|
||||
lda curtrk ; load current track
|
||||
sta tmptrk ; store as temptrk
|
||||
sec ; calc current-desired
|
||||
sbc phase
|
||||
beq seekret ; if they match, we are done!
|
||||
|
||||
bcs seek_neg ; if negative, skip ahead
|
||||
eor #$ff ; ones-complement the distance
|
||||
inc curtrk ; increment current (make it 2s comp?)
|
||||
bcc L114 ; skip ahead
|
||||
seek_neg:
|
||||
adc #$fe
|
||||
dec curtrk
|
||||
L114:
|
||||
cmp step
|
||||
bcc L115
|
||||
lda step
|
||||
L115:
|
||||
cmp #8
|
||||
bcs L116
|
||||
tay
|
||||
sec
|
||||
L116:
|
||||
lda curtrk
|
||||
ldx step1, y
|
||||
bne L118
|
||||
L117:
|
||||
clc
|
||||
lda tmptrk
|
||||
ldx step2, y
|
||||
L118:
|
||||
stx tmpsec
|
||||
and #3
|
||||
rol
|
||||
tax
|
||||
mlsmc11:sta $c0e0, x
|
||||
L119:
|
||||
ldx #$13
|
||||
L120:
|
||||
dex
|
||||
bne L120
|
||||
dec tmpsec
|
||||
bne L119
|
||||
lsr
|
||||
bcs L117
|
||||
inc step
|
||||
bne copy_cur
|
||||
.endif
|
||||
|
||||
|
||||
step1: .byte $01, $30, $28, $24, $20, $1e, $1d, $1c
|
||||
step2: .byte $70, $2c, $26, $22, $1f, $1e, $1d, $1c
|
||||
|
||||
sectbl: .byte $00,$0d,$0b,$09,$07,$05,$03,$01,$0e,$0c,$0a,$08,$06,$04,$02,$0f
|
||||
|
||||
|
||||
; From $BA96 of DOS33
|
||||
;nibtbl: .res 128 ; = *
|
||||
; .byte $00,$01,$98,$99,$02,$03,$9C,$04 ; $BA96 ; 00
|
||||
; .byte $05,$06,$A0,$A1,$A2,$A4,$A4,$A5 ; $BA9E ; 08
|
||||
; .byte $07,$08,$A8,$A9,$AA,$09,$0A,$0B ; $BAA6 ; 10
|
||||
; .byte $0C,$0D,$B0,$B1,$0E,$0F,$10,$11 ; $BAAE ; 18
|
||||
; .byte $12,$13,$B8,$14,$15,$16,$17,$18 ; $BAB6 ; 20
|
||||
; .byte $19,$1A,$C0,$C1,$C2,$C3,$C4,$C5 ; $BABE ; 28
|
||||
; .byte $C6,$C7,$C8,$C9,$CA,$1B,$CC,$1C ; $BAC6 ; 30
|
||||
; .byte $1D,$1E,$D0,$D1,$D2,$1E,$D4,$D5 ; $BACE ; 38
|
||||
; .byte $20,$21,$D8,$22,$23,$24,$25,$26 ; $BAD6 ; 40
|
||||
; .byte $27,$28,$E0,$E1,$E2,$E3,$E4,$29 ; $BADE ; 48
|
||||
; .byte $2A,$2B,$E8,$2C,$2D,$2E,$2F,$30 ; $BAE6 ; 50
|
||||
; .byte $31,$32,$F0,$F1,$33,$34,$35,$36 ; $BAEE ; 58
|
||||
; .byte $37,$38,$F8,$39,$3A,$3B,$3C,$3D ; $BAF6 ; 60
|
||||
; .byte $3E,$3F,$13,$00,$01,$02,$01,$00 ; $BAFE ; 68
|
||||
; .byte $00,$00,$00,$00,$00,$00,$00,$00
|
||||
; .byte $00,$00,$00,$00,$00,$00,$00,$00
|
||||
|
||||
|
||||
;bit2tbl: .res 86 ; = nibtbl+128
|
||||
;filbuf: .res 4 ; = bit2tbl+86
|
||||
;dataend = filbuf+4
|
||||
|
||||
Loading…
Reference in New Issue
Block a user