<pre>
;; Dissassembled and commented from MCPEN.BIN
org 09c40h
call 0bd19h ;; mc wait flyback
di
ld bc,0f40eh;; we want to select AY register 14
out (c),c
ld b,0f6h
and 030h
ld c,a
or 0c0h out (c),a ;; AY control select register.
out (c),a
out (c),a ;; BUG. Should be out (c),c to be compatible with Plus.
inc b
ld a,092h
out (c),a
push bc
ld bc,0f649h ;; AY control read from register and select keyboard line 9 (joystick) out (c),c
out (c),c
out (c),c ;; BUG? No need to do this twice.
ld b,0f4h
;; loop reading joystick until input seen or timeout
ld hl,0fa66h ;; timeoutis 0-FA66 because it counts up from this starting point. ;; timeout is 59A loops.
l9c68:
in a,(c)
inc h
jr nz,l9c68
;; timeout. not detected
ld hl,0ffffh
jr l9cbdh
l9c79:
;; detected.
ld de,00420h
add hl,de
l9cbd:
ld (0a410hdata_0a410h),hl ;; detected 'position'or 'ffff' for not detected
pop bc
ld a,082h
out (c),a
dec b
out (c),c;; Set AY control inactive.
ei
ret
ret
;; HL = HL/DE
sub_9c94:
ld a,h
ld c,l
ld b,010h;; 16 bits.
ld hl,00000h
l9cdbh:
ret
;; HL = HL * DE
sub_9caeh:
ld a,l
ld c,h
ld b,010h;; 16 bits
ld hl,00000h
l9cf5h:
;; detected.
ld de,00002h
call sub_9c94h;; HL = HL/DE
ld de,00064h
call sub_9caeh;; HL = HL*DE
ld de,00084h
call sub_9c94h;; HL = HL/DE
ex de,hl
ld hl,0018fh
sbc hl,de
ld (0a410hdata_0a410),hl
ret
sub_9ce4sub_9ce4h:
ld a,000h
ld bc,01a1ah
and a
sbc hl,de
;; BUG? This is jumping just after 0x021 of LD HL and then executing two nops before LD DE,0000h ;;jr nc,$+32 jr nc,l9d06
ld hl,00000h
l9d06:
ld de,00000h
call 0bbc0h ;; gra move absolute
call 0bc32h ;; scr set ink
ld b,00ah
l9d1e:
call 0bd19h ;; mc wait flyback
;; BUG? this is jumping back to the 0x0a in LD B,0ah ;; djnz $-4 djnz l9d1e ld b,020h;; number of lines
l9d65h:
push bc
call sub_9d35h;; draw lines
call sub_9c40h ;;detect
pop bc
sub_9d35h:
ld bc,(0a418hdata_0a418)
l9d79h:
push bc
ld hl,00014h
call 0bbf9h ;; gra line relative
ld de,(0a416hdata_0a416)
ld hl,0ffech
call 0bbc3h ;; gra move relative
ret
l9d91h:
ld de,0ffech;; -20
ld hl,00000h
call 0bbc3h ;; gra move relative
ld a,000h
call 0bbdeh ;; gra set pen
call sub_09d35h;; lines
ld a,001h
call 0bbdeh ;; gra set pen
ld de,0ffech;; -20
ld hl,00000h
call 0bbc3h ;; gra move relative
ld bc,(0a420hdata_0a420)
l9db4h:
push bc
ld a,0ffh
cp h
jr nz,l9ddahsub_9d9ah
ld de,00000h
ld hl,00014h
call 0bbf9h ;; gra line relative
ld de,(0a416hdata_0a416) ld hl,0ffech;; -20
call 0bbc3h ;; gra move relative
pop bc
djnz l9db4h
ld hl,0ffffh
ld (0a410hdata_0a410),hl
ret
l9ddahsub_9d9ah:
pop bc
ld (0a410hdata_0a410),hl
call 0bbc6h ;; gra ask cursor
ld (0a412hdata_0a412),de
ret
push hl
push de
call 09e08hsub_09e08h ld (0a414hdata_0a414),hl
ld de,05398h
ld b,004h
l9e0bh:
push bc
ld hl,(0a414hdata_0a414)
ld c,b
ld b,000h
l9e2dh:
push bc
ld hl,(0a414hdata_0a414)
ld c,b
ld b,000h
push de
ld de,00002h
call sub_9c94h;; HL = HL/DE
pop de
push hl
ex de,hl
ld de,(0a416hdata_0a416) call sub_9c94h;; HL = HL/DE
ex de,hl
pop hl
sub_9e1fh:
call 09c8ahsub_9c8ah ld hl,(0a418hdata_0a418) ld (0a420hdata_0a420h),hl ld hl,(0a410hdata_0a410)
ld a,0ffh
cp h
ret z
ld (0a41chdata_a41c),hl ld de,(0a412hdata_0a412) ld (0a41ahdata_a41a),de
l9e7ah:
ld de,0000ah
l9e85h:
push hl
ld hl,(0a412hdata_a412)
add hl,de
ex de,hl
call sub_09dbeh
call 0bbc0h ;; gra move absolute
sub_9e52h:
call sub_09ed2h
call sub_09de6h
ld hl,(0a410hdata_a410)
ld a,0ffh
cp h
call 0bb1eh ;; km test key
ret z
jp l9e52hsub_9e52h
l9ea9h:
call 0bb1eh ;; km test key
ret z
ld hl,(0a41chdata_a41c) ld de,(0a41ahdata_a41a)
call 0bbc0h ;; gra move absolute
ld hl,(0a410hdata_a410) ld de,(0a412hdata_a412) ld a,(0a41ehdata_a41e)
call 0bbdeh ;; gra set pen
ld (0a41chdata_a41c),hl ld (0a41ahdata_a41a),de
call 0bbf6h ;; gra line absolute
ld hl,(0a410h)
cp h
ret nz
l9ef5h:
pop de
ret
sub_9eb7h: ld hl,(0a41ahdata_a41a) ld de,(0a412hdata_a412)l9efeh:
and a
sbc hl,de
ret z
jp p,09ecbhl9ecbh
ld hl,l9f15h
jp 09ecehl09eceh l9ecbh: ld hl,09ed2hsub_9ed2hl9f0ehl9eceh:
ld (l9e52h+1),hl
ret
sub_9ed2h:
call sub_9e98h
l9f15h:
ld de,0ffech
ld hl,00000h
call 0bbc3h ;; gra move relative
ld bc,(0a420hdata_a420)l9f22h:
push bc
ld de,00000h
ld a,0ffh
cp h
jp nz,l9efehsub_9efehsub_9ef5h: ld hl,(0a422hdata_a422) ld (0a410hdata_a410),hl jp l9d9ahsub_9d9ah sub_9efeh: ld (0a422hdata_a422),hl ld de,(0a416hdata_a416)
ld hl,0ffech
call 0bbc3h ;; gra move relative
djnz l9f22h
ld hl,0ffffh
ld (0a410hdata_a410),hl
ret
sub_9f82h:
call sub_9e98h
ld bc,(0a420hdata_a420)
l9f5ch:
push bc
ld a,0ffh
cp h
jp z,l9ef5hsub_9ef5h ld (0a422hdata_0a422),hl ld de,(0a416hdata_a416)
ld hl,00000h
and a
call 0bbc3h ;; gra move relative
jp l9f0eh
nop nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nop nop;; screen dump to printer. nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nopla050hsub_0a028h: nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop ld a,013h;; INC instruction ld (la124hla124),a
ld a,00eh
ld (0a0e2hla0e1+1),a ld a,(la133hdata_a133)
bit 1,a
jr z,la083h
ld a,000h ;; NOP instruction ld (la124hla124),a
ld a,007h
ld (0a0e2hla0e1+1),a
la083h:
call 0bd28h ;; mc reset printer
ld de,00000h
ld hl,00000h
ld (0a12dhdata_a12d),desub_a050h:
ld a,000h
ld (0a12chdata_a12c),a;; accumulated pixels. ld de,(0a12dhdata_a12d) call sub_a10dh;; store current graphics position
call 0bbf0h ;; gra test absolute
ld de,00001h
call sub_a11dh;; get pixel
ld de,00002h
call sub_a11dh;; get pixel
ld de,00004h
call sub_a11dh;; get pixel
ld de,00008h
call sub_a11dh;; get pixel
ld de,00010h
call sub_a11dh;; get pixel
ld de,00020h
call sub_a11dh;; get pixel
ld de,00040h
call sub_a0ffh;; get pixel
la0c9h:
call 0bd2eh ;; mc busy printer
jr c,la0c9h
call 0bd28h ;; mc reset printer
ld a,01bh ;; ESC
call 0bd2bh ;; mc print char
ld a,04bh ;; K
call 0bd2bh ;; mc print char
ld a,000h ;; number of columns low byte
call 0bd2bh ;; mc print char
ld a,(la133hdata_a133)
bit 0,a
jr z,la0f4hla0b4h ld a,002h ;; number of columns high byte?
call 0bd2bh ;; mc print char
ld a,(0a12chdata_a12c);; pixel data
call 0bd2bh ;; mc print char
jr la0f9h
la0f4hla0b4h: ld a,001h ;; number of columns high byte?
call 0bd2bh ;; mc print char
la0f9h:
ld a,(0a12chdata_a12c);; pixel data
call 0bd2bh ;; mc print char
sub_a0ffh:
call sub_a115h
inc hl
ld a,h
cp 001h
jp nz,la050hsub_a10dh:sub_a050h
ld a,l
cp 090h
jp nz,la050hsub_a050h ld a,00ahsub_a115h: ;; next line call 0bd2bh;; mc print char ld a,02fh ;; 47 - space
call 0bb1eh ;; km test key
sub_a11dh:
ret nz
ld hl,(0a12dhdata_a12d)la0e1:
ld de,0000eh
la124h:
add hl,de
ld (0a12dhdata_a12d),hl
ld hl,00000h
call sub_a10dh
ld de,(0a12dhdata_a12d)
ld a,d
la133h:
cp 002h
jp nz,la050hsub_a050h
ld a,e
cp 084h
jp nz,la050hsub_a050h
ret
;; accumulate pixels
sub_a0ffh:
ld b,a
call 0bb99h ;; txt get paper
cp b ;; was the colour read the same as the paper?
ret z
;; any pixel which is not the same as the paper will be considered foreground ;; and the printer will draw a dot. Any pixel the same as the paper will ;; be considered background and no dot is drawn by the printer. ;; pixel is set to foreground. accumulate it into the pixel data so far ld hl,(0a12chdata_a12c)
add hl,de
ld (0a12chdata_a12c),hl
ret
sub_a10dh: ld (0a12fhdata_a12f),hl ld (0a131hdata_a131),de
ret
sub_a115h: ld hl,(0a12fhdata_a12f) ld de,(0a131hdata_a131)
ret
sub_a11dh: call sub_a0ffh;; accumulate a pixel for printing. call sub_a115h;; get current X/Y graphics position inc de ;; increment X to next pixel accross screen.la124:
inc de
inc de call sub_a10dh;; set current X/Y graphics position
call 0bbf0h ;; gra test absolute
ret
nopdata_a12c: add a,hdb 00hdata_a12d: ld (bc)db 84h,a02h nopdata_a12f: nop ld cdb 00h,000h00h nopdata_a131: nopdw 000eh nopdata_a133: nopdb 00h nopdata_a134: nopdb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nop nopla18bhsub_a154h: nop nop nop nop nop nop nop nop nop
call 0bc11h ;; scr get mode
cp 000h
ld a,b
la1aah:
ld (0a254hdata_a254),a
call 0bbc6h ;; gra ask cursor
ld (la250hdata_a250),hl ld (la250hdata_a250+2),de
la1b7h:
call 0bb99h ;; txt get paper
ld (la1f9hpen_cmp+1),a
ld bc,00000h
ld (0a24chdata_a24c),bc ld (0a24ehdata_a24e),bc call 0a210hsub_a210la18bh: ld a,02fh ;; 47 - space
call 0bb1eh ;; km test key
ret nz
ld hl,(0a24ehdata_a24e)
inc hl
inc hl
ld hl,00000h
la1deh:
ld (0a24ehdata_a24e),hl
ld bc,05398h
add hl,bc
ld (la1aahbuffer_addr3+2),hl;; +2 to skip ED,53buffer_addr3:
ld de,(055e0h)
ld hl,(0a24ehdata_a24e)
sub_a1efh:
ld bc,057e4h
add hl,bc
ld (la1b7hbuffer_addr4+1),hl;; +1 to skip 22buffer_addr4:
ld hl,(05a2ch)
la1f9h: ld (la257hdata_a257),hl ld (0a255hdata_a255),de
ld bc,00000h
ld a,(0a254hdata_a254)
ld c,a
ex de,hl
dec hl
call sub_a1efh
ld hl,(0a24ehdata_a24e) ld de,(0a24chdata_a24c)
inc hl
inc hl
ret z
jp la18bh
sub_a1efh:
push de
push hl
pop bc
pop hl
la237h:
pop de
pen_cmp:
cp 000h
jr nz,la248h
ld (la250hdata_a250),hl ld (la250h+2data_a252),de
push bc
call 0a210hsub_0a210h
pop bc
la248h:
ld hl,(la257hdata_a257) ld de,(0a255hdata_a255)
ret
la250hsub_a210: ld hl,(la250hdata_a250) ld de,(la250h+2data_a252)la257h:
call 0bbeah ;; gra plot absolute
ld hl,(0a24chdata_a24c)
inc hl
inc hl
ld hl,00000h
la267h:
ld (0a24chdata_a24c),hl
ld bc,05398h
add hl,bc
ld de,(la250h+2data_a252) ld (la237hbuffer_addr1+2),hl;; +2 to skip ED, 53buffer_addr1:
ld (05648h),de
ld hl,(0a24chdata_a24c)
ld bc,057e4h
add hl,bc
ld de,(la250hdata_a250) ld (la248hbuffer_addr+12),hl;; +2 to skip ED, 53buffer_addr2:
ld (05a94h),de
ret
or b
ld (bc),a
ld c,b
ld (bc),a
cp (hl)
nop
jr nz,la295h
inc b
la295h:
jr nz,$+3
cp h
;;Data areadata_a24c: defw 02b0hdata_a24e: defw 0248hdata_a250: defw 0behdata_a252: defw 0120hdata_a254: defb 04hdata_a255: defw 0120hdata_a257: defw 0bch ;; detected light pen positiondata_a410: defw 0data_a412: defw 0;; memory/buffer addressdata_a414: defw 0data_a416: defw 0data_a418: defw 0 ;; gra x,y positiondata_a41a: defw 0data_a41c: defw 0;; graphics pendata_a41e: defb 0 defb 0data_a420: defw 0 end</pre>
[[Category:Source code]]