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Prportional Ascii text scrollerA couple of years ago I wrote a little scroller that nestles at the top of RAM (FFCA - 65482) and scrolls standard Ascii encoded text from anywhere y…
... ,a ;get bit 7
jr nc,scroll ;if set, jump ... line down
db 18h ;(jr scr_lp0)
;use F3h from ... -
Printing text, part MMXIIXI'm pretty sure there's been a zillion threads about this already, and I don't think it's the first one by myself either, but here goes. Proportiona…
... br /> dec e
jr NZ, fastwidthloop
jr chardone
...
dec e
jr NZ, widthloop
... /> or a, a
jr NZ,nextchar
lastchar:
... inc -4 (ix)
jr NZ,dataadd16
inc -3 (ix ... -
Help With infinite music on 128KHi :) I'm trying to play infinite simple music on 128K , but i don't know what is wrong with the loop I tried this routine but doesn't work I…
...
ei
jr $ ; infinite loop only waits for ... hl)
or a
jr nz,waitSound
inc hl
cp $FE
jr z,jumpNotes
ld bc ... a
inc hl
jr bucle
waitSound
Textured Scanline Flood Fill for ZX Spectrum 48KPity that it's quite hard to contribute code to WoS in a straightforward manner. Recently, I have created a textured/hatched fill M/C routine for the…
Pity that it's quite hard to contribute code to WoS in a straightforward manner. Recently, I have created a textured/hatched fill M/C routine for the ZX Spectrum 48K. It was for a text/graphic adventure I'm working on. The algorithm is based on [url="http ...Q. on most/least number of instructions per [unit].Errr ... I believe I bumped into a thread on this subject about a decade or two ago but I can't find it (didn't look too hard). And I think this was …
... />
How many instructions per cycle can the Speccy do?
clock cycle, other?line routineWondered if anyone can help me out. I have been programming a 3d graphics library for the spectrum, in Machine code. The line routine that I have i…
... ,A
........DEC E
........JR NZ,bit
........OR (HL)
........AND 7
........JR NZ,cnt ; only 1 every 8 ... AF
........DEC D
........JR NZ,vloop
........RET
line routineWondered if anyone can help me out. I have been programming a 3d graphics library for the spectrum, in Machine code. The line routine that I have i…
... it
........DEC E
........JR NZ,bit
........LD E,A ... adrescalculation
........DEC D
........JR NZ,vloop
........RETline routineWondered if anyone can help me out. I have been programming a 3d graphics library for the spectrum, in Machine code. The line routine that I have i…
... ,d
and 7
jr nz,filltab
ld a,d ...
ld e,a
jr nz,filltab
ld a,d ... ,a
cp #58
jr nz,filltab
ld sp,(sstack ...line routineWondered if anyone can help me out. I have been programming a 3d graphics library for the spectrum, in Machine code. The line routine that I have i…
... /> jp z,or_fim2
jr nc,dym
ld a ... /> ld b,l
jr startver
dym: sub e ...
AND 7
jr nz,nexty
ld a,l ... /> ld a,1
jr z, or_pixel3 ; pixel is at ...line routineWondered if anyone can help me out. I have been programming a 3d graphics library for the spectrum, in Machine code. The line routine that I have i…
... rrca
inc l
jr nz,lp_mpt1
inc h
inc l
jr nz,lp_mpt2
inc h
and #07
jr nz,$+12
ld a,e ...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
hi arjun and look again. there is 'JR NZ' so the results would be 81h, 85h, 0dh and 80h unless there is more after the label change...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
umm..but the JR NZ would be exectued only if ... will result in a failed JR NZ (since comparison fails) and will ...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
... to machine code basics:
jr nz would be executed always, but ... with the instruction after the jr nz
if the zero flas ... />
and you've mistaken jr nz for jr z which acts inversely...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
Right. I had indeed gotten the JR NZ and JR Z mixed up!
Happens to me all the time! [img]/__forums/images/smiles/icon_frown.gif[/img] .
My mistake!ScrollingBit of a daft topic but anyway... Which game had the best scrolling? I would have to volunteer Commando and its silky-smooth scrolling. A particula…
... the attribute map
jr nz,loop ; we've not ... reached the ROM
jr nz,nextln ; we've still ... get 128 (8x2x2x2x2)
; jr z,scrollup
; srl a ... move down
; jr z,scrolldown - do it four ... br /> cp 5Bh
jr nz,scl ; not reached the end ...Machine Code ChallengeHere's a challenge for all you Z80 programmers. Points to be awarded for elegance and brevity. (I haven't got the solution either) HL addresses the …
... a ;test for #ff
......jr nz,found0 ;byte with first 0 ... once so use jr
......dec b
......jp nz,searchfor0 ;jump ... starts the main loop
......jr z,done ;jump only once ... so jr
......inc hl
......ex ...Machine Code ChallengeHere's a challenge for all you Z80 programmers. Points to be awarded for elegance and brevity. (I haven't got the solution either) HL addresses the …
... a ;test for #ff
.....jr nz,found0 ;byte with first 0 ... the next masking bit
.....jr nc,buildmask ;loop uless we ...adding colourThis my sound like a real stupid Q but when programing a picture how do i add colour like filling in shapes with colour. What kind of programming sh…
Horizontal scrollDoes anyone know how to do a 2 or 4 pixel left or right horizontal scroll of the spectrum screen. I can make a 1 one pixel scroll with: ... rl (hl…
Paging questionI've a question regarding paging on the Spectrum 128K, +2, +2A, +3, etc, etc. Suppose we are running a program in the page that happens to be.. well,…
It would be even if paging took time - more than one clock cycle at least - the memory is a copy. There is no floating zone where the databus is inconclusive.128 Memory PagingI'm having a problem getting my brain around paging. Well, actually the bit I don't understand is how reading I/O ports works! I hope the collective …
ZX81 and ZX80 emulator on Spectrum 128KA couple of weeks ago we were talking about a new ZX81 emulator for the 128K. Someone beat me. More details at [url="http://www.fruitcake.plus.com/S…
... LD A,E ;
JR C,L0388 ; loop back ... /> POP DE ;
JR NZ,L039C ; to BIT-DONE
CP $56 ;
JR NC,L034E ; to NEXT-BIT ...ANARCHY v1.0 remake for PC releasedThanks to everyone's help here with pokes and other info for the original game, the remake is finally out after about 6 or 7 weeks of hard coding. I…
... for the majority of the clock cycle in most 2D games. Blitz ...
