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Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... H
DEC C
JR NZ, Loop2
LD H, & ... /> NOP
DEC B
JR NZ, Loop1
RET
[/code ... -
Fast way to clear the screen ?So I was wondering fastest way to clear the screen. I've tried this and this works but is it better than CLS ? LD HL,16384 LD BC, 6144 Loop…
A sped up pixel-shift routine for 1-byte–wide spritesHere’s an optimized (for speed) real-time sprite shifting routine for sprites that are one byte wide. It uses no memory variables for storage of inte…
... a ;is it zero?
jr z,msl_skip_shift ;okay, no shifting ... will be 0 then
jr nz,msl_shift_done ;if not, we're ... it back in L
jr c,msl_shift_done ;if ADD A ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... ; 13t - into later code
jr _ulzfa020 ; 12t
;;
;; ... then need next byte
jr nz,_ulzfa030 ; 12/7t - 7 ... inc hl ; 6t - next
jr _ulzfa020 ; 12t - back to the ... *** loaded from above
ret nz ; 11t - if not equal to ...Flood Fill IssueHi Folks, Came across the following Flood Fill routine by John Metcalf: [code]; scanline fill by John Metcalf ; call with d=x-coord, e=y-coo…
... a 60020 B7
jr z,goright 60021 28 ... 98 EA
jr nz,seekleft 60029 20 F4< ... d 60033 14
jr z,rightedge 60034 28 12 ... e 60051 1C
jr seekright 60052 18 E9
jr nz,nextrun 60057 20 CC
A Neat Redefine Keys RoutinePreviously, I’ve only shared this routine with a couple of people via PM, but I’ve now decided to make it public. I optimized it for size, so it uses…
... 32 ;is it SPACE?
jr nz,enter_key ;if not, check if ... 13 ;is it ENTER?
jr nz,ss_key ;if not, check if ... ;is it SYMBOL SHIFT?
jr nz,cs_key ;if not, check if ... ;is it CAPS SHIFT?
jr nz,as_is_key ;if not, then print ...Other than using attributes what other ways to detect collisions, when using char based movement?So I'm slowly working out the bits and pieces to write a game completely in assembly. I've been using attributes when writing in BASIC to detect whet…
No-tearing (“vsync”) Full Screen FadeSeeing as most screen fades exhibit visible tearing, I wrote my own routine which does away with that problem. Simple, effective, short, and fully re…
... timings of different machines
jr nz,1$ ;before we start drawing ... ,a ;copy into C
jr z,f1 ;leave it alone ... /> and $38 ;isolate PAPER
jr z,f2 ;leave it alone ... end of attr area?
jr nz,fade1 ;repeat if not
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
type in to learn about IM2I'm trying to mess around with learning about IM2 and I found a nice little article in Sinclair User September 1988, issue 78, Page 70-71 [url="https…
...
clock_on:
jr INT_ON ;on entry point
inc L
jr nz, INT10
inc H
dec (HL)
jr nz, PRINT_TIME
ld (HL), 50 ... HL)
cp (HL)
jr nc, PRINT_TIME
ld (HL ...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 ...Console frameworkStill working on Specotron, but at the point where working out the diagonal lines collision is not good at beer o'clock. In the meantime I've knoc…
... 8
dec c
jr nz, .nextbyte
ENDIF
... e
or a
jr nz, .somethingpressed
inc a ; clear ... =0)
or a
jr nz, .nothalfline0
ld a, ... /> ld a, (hl)
jr nz, .getkeyval
bit 1, a ...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!
