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Indirect Variable AssignmentHere's another wacky routine. This allows assignment of values to variables where the source & destination variables can themselves be defined in var…
Here's another wacky routine. This allows assignment of values to variables where the source & destination variables can themselves be defined in variables (or expressions which evaluate to variables). Some of this can already be done with VAL or VAL$, ... -
Undefine functionHere's a routine to selectively remove variables from the VARS area and reclaim the space. This can be done partially from BASIC already by assigning…
...
pop de
jr c,CHKNXT ;variable already undefined ... $E0
cp $E0
jr nz,NOTFOR ;not a for...next ... variable
call RECLAIM2
jr CHKNXT
;string ... -
joining lines of BASICDue to overwhelming demand - well, one demand - well, more of a suggestion, really - here's a routine to join together lines of BASIC. The vertical c…
... cp 7 ;EDIT
jr nz,NOTEDIT
set 6,(IY ... :cp $0d ;ENTER
jr nz,NOENTER
res 6,(IY ... CP 11 ;cursor up
JR NZ,FINISH
CURSUP: ... -
The INPUT command routine ($2089)I was looking at the INPUT routine with a view to modifying the intro so that I could pre-load the workspace and edit an existing value, rather than …
... , check the INPUT for
JR 2161,IN-VAR-4 errors ... is taken if using
JR NZ,2174,IN-VAR-5 other ... -
AZIMUT / Frecuency spectrum[code]start DI LD HL,#7F40 LD D,#58 loop LD B,#00 bucle1 LD A,H IN A,[#FE] XOR A,C AND A,L J…
...
AND A,L
JR NZ,findA
DJNZ bucle1
AND A,L
JR NZ,findB
DJNZ bucle2
RRA
JR C,loop
EI
Routine for clearing screenI was looking for a 'nice' way of clearing a screen of graphics in Z80. After a ridiculous amount of time mucking around, this is the best and most …
... ,b
or c
jr nz,SCREEN_CLEAR_LOOP
ld a ... />
ld (PRT_CHR),a
jr START
PRT_CHR
Inefficient code in ROM, from ram-check to RAM-DONEHere is the inefficient code: [CODE] ;; ram-check L11DA: LD H,D ; Transfer the top value to the HL register LD L,E …
... we reached ROM - $3F ?
JR NZ,L11DC ; Back to RAM-FILL ... (HL) ; decrement to 1.
JR Z,L11EF ; forward to RAM ... ; increment for next iteration.
JR Z,L11EA ; forward to RAM ...Jelly-Vision!As threatened in the "'Spectrum Play' Error" thread, here's a ruff'n'reddy interrupt driven full screen wobbling routine which has no practical use w…
... printing in lower screen?
jr nz,TESTSCROLL
bit 1,( ... br /> cp $0e
jr z,INSCROLL
push bc ... ld bc,6144-256
jr nz,MOVEUP
MOVEDOWN: ld hl ...40 Column Printing RoutineI've written a 40 column printing routine, which I'd like to share... It's my first piece of 'public' code so go easy on me! I don't think it is a…
... br /> cp 13
jr z,foundcr ; recognises some ... a
inc hl
jr nextchr
rst16replacement ... br /> and a
jr nz,skipoverprint
push hl ; ...Any ideas on speeding up this assembler segment?It copies a pixel column of a rectangle which may be anywhere in the display file to a pixel column in d$. The source column may start at any bit pos…
...
and $01 ; 7
jr z,next_d ;12
;** = 62 ... column scan depth remaining
jr nz,for_d ;12
;** = 64
BeepFX ProblemHi All, I'm currently trying to integrate the BeepFX engine in my 100% Assembler Game and it plays the sound fine, but then plays the sound again, a…
... ,b
or c
jr nz,SFXRTl1
ld a,(SFXRTDUTY ... b
or c
jr nz,SFXRTl0
ld c,11 ... a
dec d
jr nz,SFXRNl2
ld d,e ...Kempston detectionI could use some help. This Kempston joystick behaviour drives me mad. I've written a game called Necrospermia recently ([url]http://www.worldofspec…
... )
BIT 0,A
JR NZ,StartAnim3
XOR A ... )
BIT 4,A
JR Z,StartAnim4
LD ... /> RET
StartAnim4
JR StartAnim2 [/CODE]Using R as a loop counterThis is just something silly I've found a while back. xD [b][How-to][/b] Setup your routine like this:[code] ld a,X ;see below ld r,a loop ;your …
...
ld a,r
jr nz,loop[/code]Here, X is ... the final 'ld a,r: jr nz,loop' commands) which you need ...
ld a,r
jr nz,.l2
ld a,b ...multi-scroll m/c subroutine for BASICArising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. whe…
Arising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. where width iscalculator and sinusok, look at the Sysel's routine: [PHP]3 5b00 *s 4 5b00 tabsin = #7000 03 mksin 19.11.1995 Busy soft …
... l
26 8022 20e3 jr nz,mksn1
27 8024 se ...Graph Plothi! please, help with code: [PHP]For x=-100 To 100 For y=-100 To 100 If (x/2-25)*(x/2-25)+(y-50)*(y-50)<200 Or (x/2+25)*(x/2+25)+(y-50)*(y-50)<200 th…
hi! please, help with code:
[PHP]For x=-100 To 100
For y=-100 To 100
If (x/2-25)*(x/2-25)+(y-50)*(y-50)Optimisations in Exomizer Z80 decrunch codeThis is the 163 bytes old code (simple and optimized): [CODE] ld iy, exo_mapbasebits ld a, 128 ld b, 52 push de exo…
... , hl
dec c
jr nz, exo_setbit
exo_one:
ld ... br /> ld c, 16
jr nz, exo_get4bits
ld de, 1 ... , hl
dec c
jr nz, exo_setbit
exo_one:
ld ...MultifaceOneCrack-Killer.tzxhi all just wondering if anyone has ever tried to use this tool? i have had a look at it and think i understand wot it's ment to do but the code loo…
...
JR NZ, 24160
JR NZ, 24162
JR NZ, 24164
JR NZ, 24166
JR NZ, 24153 ... 8301
JR NZ, 24177
JR NZ, 24179
JR NZ, 24181
JR NZ, 24183
Machine code loopsDear all, 30 years too late I know, but I'm finally starting to get to grips with Machine Code - something I could never manage back in my early tee…
... 6912, dec it, and use jr nz,-10 ?
(Actually, have ...Works in Fuse & SpecEmu, not ZXSpinI decided that I wanted to change the scroll routine which I was using for compiling the Trailblazer maps, as I'd just copied it out of Andrew Hewson…
... cp $ff
jr nz,PRINT2
pop af ... /> dec a
jr nz,PRINT1
... call $15de ;WAIT_KEY1
jr PRINTMAP
... /> dec a
jr nz,PATLOOP
ret
Idk>le me browsing through some game's code >..... [code]61A8 F5 push af 61A9 3EFF ld a,FF 61AB D37F out (7F),a 61AD D33F ou…
... cp B5
6202 20DF jr nz,61E3
6204 CDC362 ... br /> 6230 20F6 jr nz,6228
6232 18AF jr 61E3
... ,001A
624C 18DA jr 6228
624E CDC362 ... or c
6277 20F6 jr nz,626F
6279 3D ...Cobra (improved again BUGFIX)This is an improved BUGFIX for game [URL="http://www.worldofspectrum.org/infoseekid.cgi?id=0000996"]Cobra[/URL], that works better than the fix curre…
... /> 9604: cp b
9605: jr nc,$9601 ; repeat forever!
9604: nop
9605: jr nz,$9601
9607: ret
Adding a pause key to ArkanoidHaving rediscovered the simple pleasure of playing 1980s games on genuine 1980s hardware, I've also remembered that emulation can provide a feature m…
... again
rra
jr nc,$ - 3 ; keep probing ... ei ; restore interrupt handler
jr .return_to_game[/CODE]
... br /> dec a
jr nz,$-1
and a< ...Movin And A Groovin Horizontal Flip improvementOn the left is the flip horizontal portion from Andy Pennell'S excellent Movin' & a Groovin' machine code screen routines from Your Spectrum #19 (Oct…
... ;a=GHABCDEF
JR NC,SWITCH ;turn around ; ...
JR NZ,FLIPH ;do all the columns JR NZ,fliph
DEC C
JR NZ,fliph
RET
...MGT MOUSE - exist really ?I read disassembly of +D rom/ram code and from address #2249 is routine for read MGT MOUSE ports. I can't find any info about "MGT MOUSE". Exist real…
... br /> 2250 RET NZ Return if no ... br /> 2264 RET NZ Return to vertical movement ... br /> 227A RET NZ Return to signal ... D
227D JR NZ,#2285,MOVE_UP Jump if ...SCREEN$ bug fixI've been using the SCREEN$() function recently for reading data off the screen rather than taking up space with an array and I got fed up with the s…
... ]
ScrDol0:call ScrDol
jr nz,ScrDone
call $2bf1 ;STK_FETCH ... )
ld (23606),hl
jr z,ScrDone
ld a ...
