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[Asm] Is this nested loop faster than LDIR or a bunch of unrolled LDI's?Hi all. I'm learning Z80 asm on Speccy 48K, and to start with I decided to write my own "CLS" routine (without relying on ROM calls or LDIR) as a lea…
... %00000000 ; Usage example: ld a,FLASH_OFF | BRIGHT_ON | PAPER_BLACK ... /> ld a,BORDER_BLACK ; Select a color.
ld (SYSVAR_BORDCR),a ; Save ... ld a,FLASH_OFF | BRIGHT_ON | PAPER_BLACK | INK_WHITE ; Select attributes.
ld (SYSVAR_ATTR_P),a ... -
this code wont give me a random starfieldim using a peice of code that ive copied from a book, ignore most of it as it is redundant. for some reason i get a strange random starfield instead …
... vertical position of player.
ld a,(ply) ; player's horizontal position ... our temporary screen colours.
ld a,32 ; SPACE character.
rst ... 8k of ROM.
ld h,a
ld a,(hl) ; Get "random" number ... -
Tricks to make mirror image of a graphic?I've been working on a sprite routine for lots of sprites and animations. I'm only storing right facing graphics, and converting them to left facing.…
... />
ld a, c
add a, %10000000
ld c, a
b1: ld a, (de ... />
ld a, c
add a, %01000000
ld c, a
b2: ld a, (de ...
ld a, c
add a, %00100000
ld c, a
b3: ld
FrankT
December 2020
Assembler
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Sort 2 byte words (x, y) on ypos, also question about swap (DE), (HL)Well that was a lot of debugging ;) But if you want a routine which takes an array of 16 byte words x, y and then sort them on y (ignoring x), I'm…
... , af' ; remember right in A'
ld a, (hl) ; A = data[right].y
int r = 2 * i + 2;
< ...
// so far
if (r < n && arr ... [r] > arr[largest])
largest = r;
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…
... /> ld a, (bc)
ld e, a
inc c
ld a, (bc)
ld d, a ...
inc c
ld a, (bc)
ld l, a ...
inc c
ld a, (bc)
ld h, a ...How do i learn to programAll the years i had a computer the only one i could program was the Texas Instruments Ti99/4a and when using extended basic with its so simple sprite…
... .
If u r using an assembler, the assembler ... /> LD HL, 32000 ;memory location for storing the number
LD A, ... 2
LD BC, 2 ; we are ... anything.
LD (HL), A ; stores the contents of A in the ...How do i learn to programAll the years i had a computer the only one i could program was the Texas Instruments Ti99/4a and when using extended basic with its so simple sprite…
... .
If u r using an assembler, the assembler ... /> LD HL, 32000 ;memory location for storing the number
LD A, ... 2
LD BC, 2 ; we are ... anything.
LD (HL), A ; stores the contents of A in the ...Randomize USR xxxxxA weird topic: When I was a kid I use to mess around with the RANDOMIZE USR xxxxx, sad I know!!! For instance RANDOMIZE USR 51234 would give me a loa…
... to Happen?!?"
50 Let R = Rnd*16384
60 Pause 100 ... 50
90 Randomize usr r
Enjoy!
If ... then I'll send you a tap file. But dont all ...Machine CodeOk i had a spectrum when i was younger and only used it for playin games and typing simple BASIC programs - i mean really simple! Things like 10 Pri…
... are done with labels.
A small example is this
LD HL,message
LOOP LD A,(HL)
OR A
RET ... LOOP
message DEFB "P","R","I","N","T",0
A)
If no errors ...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…
...
You'd probably get a speed gain here by loading ... into a register first.
ld a,(hl)
rla
rla
ld (hl),a
dec ... RLA is quicker than RL A (4 compared to 8 ... cycles), or RL r in general. Not much ...Anyone for a hacking challenge ?I have to get the DSK version of Tomahawk to work. It uses the well-known Digital Integration "SECURITY CODE" lock just like in Bobsled, ATF, etc. Th…
... the Multiface and then press 'r' to return. Where Genie says ... follows:-
LD A, (40000)
DEC A ' option appears again leaving ... 3E 03 LD A,03
Now press A to (A)lter the ... menu to select a choice!)
Now press R to (R)eturn to ...+D/Disciple games archive?Hi all, Having finally got my disciple to work, I'm starting to have a look at hacking multiload games. Is there any archive on the web with games t…
... I'll step you through R-type, since this is ... hl
ld a,h
cp 060h
ld a,(0719ch)
... data block named "r-typeA.dat". The "r-type" part of ... modified game snapshot in "r-type.z80" and the ... with 'SAVE "R-TYPE" LINE 1' -- a listing of this ...Interrupts details questionSuppose I am writing a game and I want to use interrupts to measure time, draw the screen without flicker, maybe to poll keyboard etc. What kinds of …
... this program
.byte 0 ;R
.word 0 ;AF
a
srl a
srl a
ld b, a
ld a, h
sla a ...
sla a ...I need ASM for random numberI need to generate a random pair of coardinates in asm so that x=random no between 0 and 31, y=random no between 0 and 23. Any ideas on how to code …
... pointer
ld d,a ; save range
ld a,(hl) ; fetch rnd
inc ... />
So
LD A,6
CALL RND
will produce ...Cobra - scrollingHi everyone, I have been studying some of the code in Ocean' Cobra game using a debugger, in the hope of improving my own scrolling routines. In cas…
Well it seems Woody is hottest. The ISR loads R with FFh.
[code]
ei
push af
ld a,ffh
ld r,a
pop af
reti
[/code]
DerekReading the keyboardDoes anyone have a code sample to read the keyboard in machine code ?
...
.nosym
ld a,(hl) ; a = ascii code
scf ; indicate ... 'q','w','e','r','t' ; Q, W, E, R, T
defb ... ,132,133,'' ; Q, W, E, R, T
defb '!','@','#','$','%' ; 1, 2 ...Games that cannot be completed due to bugs - the definitive listIt would be nice if the community of WoS compiled a list of all the games that are known to be impossible to complete due to bugs. Perhaps one day, a…
... ,right,up or down (L,R,U,D).
... br />
[code]
38196 Ld a,(33824) ;Current Room
38199 ... 38230
38212 ld a,1 ;
38214 ld(34252),a ; We are at ... br /> 38217 ret
38218 ld a,(34270) ;Number items collected PLUS ...Key press to ASCII valueI need a bit of code that will give me an ASCII value when the key is pressed. I only really need a-z. I tried using the following code but it only s…
...
.nosym
ld a,(hl) ; a = ascii code
scf ; indicate ... 'q','w','e','r','t' ; Q, W, E, R, T
defb ... ,132,133,'' ; Q, W, E, R, T
defb '!','@','#','$','%' ; 1, 2 ...Machine Code: quicksort optimisationI came across this z80 quicksort implementation when going through the wikipedia article on the same. It's 44 bytes long. I was wondering if any of …
... /> ld a,(bc)
ex af,af
ld a,(hl)
ld (bc),a
ex af,af
ld (hl),a
ld a,(bc)
ex af,af
ld a,(hl)
ld (bc),a
Key press to ASCII valueI need a bit of code that will give me an ASCII value when the key is pressed. I only really need a-z. I tried using the following code but it only s…
... hl,de
ld a,$fe ; check on CAPS key ... br />
NoSym: ld a,(hl) ; a = key code from translation ... ,84 ; q w e r t
defb 17 ... 52 ; Q W E R T
defb 17 ...Xenon TriOxide (Xeo3)I just wanted you all to know that a new cross platform game has started development (well the +4 version has been around a while, but my colleague f…
... : inc hl ; 64022
ld a, (hl) ; 64023
... br />
R-type has more advanced ... inc h ; 35184
ld l, c ; 35185
R-type works but ...Noob to Z80 needing +3 helpI'm quite new to z80 programming, but i'm attempting to write some kind of windowing system that will run alongside BASIC on my +3 with Kempston mous…
... :
[code]
let r = USR 32768: REM move 3 ... ,100,20
let r = USR 32768, "move 3,100 ... ,20"
let r = USR 32768, "move", a, 100, 20
ld a,10
ld (flag),a
ld hl,text
loop:
ld a,(hl ...Multiface ResidentI'm thinking about adapting some existing code to be Multiface "resident"... but being perfectly honest I'm not quite sure where to start. Any top t…
... enable the Multiface then press 'R'eturn. Now Randomize usr 4e4 ...
ld hl,8195
ld (hl),82; 'R'
inc hl ...
ld (hl),85 ... ),62
inc hl ; ld a,6
ld (hl),6
The Non Randomness of Sam BasicHows about this for weird. Hardly ever bothered with such simple stuff before but this is what I just did on the Sam ( as in a real one now I've got …
... in C.S.S[/url] a year or two ago. One ... [code]
1 DEF FN r(c,d,p)=c+(p ... PLOT FN r(RND*255,255,PEEK 23672),FN r(RND*175,175, ... /> [/code]
Which is a much better pseudo-random generator ... (in that it generates a display of points that [i ...Oneliner contestHello to you all, I dare you to make a program on 1 BASIC line. Here is the place to sent your ONELINERS [url]http://www.zxspectrum.00freehost.co…
... $: LET C=32: LET A$="": FOR A=0 TO 2: P
)+(P>20)): NEXT A: LET P=P*(P0)*(P1 ... G: LET S=S+10*(A>4)*(S16: LET S ...Oneliner contestHello to you all, I dare you to make a program on 1 BASIC line. Here is the place to sent your ONELINERS [url]http://www.zxspectrum.00freehost.co…
I presented before a couple one-liners implementing Soko- ... /> READ c:
POKE USR "a"+f,c:
NEXT f ... =1 TO 1e9:
LET r=RND:
LET i=(INKEY$="7 ... ,RND*29+1; INK 3-2*(r>.1);CHR$ (46+98*(r ... >.1));AT 21,29*r ...Oneliner contestHello to you all, I dare you to make a program on 1 BASIC line. Here is the place to sent your ONELINERS [url]http://www.zxspectrum.00freehost.co…
... Saukas;210649]I presented before a couple one-liners implementing Soko ... /> READ c:
POKE USR "a"+f,c:
NEXT f ... =1 TO 1e9:
LET r=RND:
LET i=(INKEY$="7 ... ,RND*29+1; INK 3-2*(r>.1);CHR$ (46+98*(r ... >.1));AT 21,29*r ...
