-
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…
... /> ld hl,&xx00
ld de,&xx01
ld bc,&0100
ld (hl ... /> --your program--
ld hl,(counter)
ld bc,hl
ret
org &zzzz
ld hl,(counter ... -
Fantasy Z80 instructions?This follows on from something catmeows said in another thread, and that I've been meaning to ask for a while. This may sound daft to people with mo…
Multiply
Mirror
LD AF,nnnn
LD BC,(HL)
LD DE,(HL) -
Fantasy Z80 instructions?This follows on from something catmeows said in another thread, and that I've been meaning to ask for a while. This may sound daft to people with mo…
... /> Mirror
LD AF,nnnn
LD BC,(HL)
LD DE,(HL)[/QUOTE]
But also:
LD HL,(IX) ;there's many an ... (nn)
maybe CALL (HL) too, but I'm just ... -
Scrolling attribute thingJust messing with scrolling attributes. Its absolutely no use, but impressed with the variable speeds of scrolling. [url]https://dl.dropboxusercont…
Or you could ld bc, hl; clear hl, ld de with a, add hl, de (3 times, so hl = a * 8 - stoopid smileys) and then ld de, bc and add hl, de. Dunno which would be faster... but there's no messing with the carry flag or shifting d involved with that method. -
Scrolling attribute thingJust messing with scrolling attributes. Its absolutely no use, but impressed with the variable speeds of scrolling. [url]https://dl.dropboxusercont…
... ]Or you could ld bc, hl; clear hl, ld de with a, add hl, de (3 ... times, so hl = a * 8 ... ) and then ld de, bc and add hl, de. Dunno which would ... -
The Pros and Cons of "alternative" assembler syntaxContinuing from [URL]http://www.worldofspectrum.org/forums/showpost.php?p=720754&postcount=72[/URL] [QUOTE=u6c87;720754]But that wouldn't change if…
... , stx, movfw, etc... instead of ld). That way surely leads to ... . Things like "ld bc,hl" which gets expanded to "ld b,h; ld c,l ... -
Problem with BC corrupting after DJNZJust for fun, I'm messing around trying to get the level maps from Lemmings to display on the screen with machine code. It's been ages since I did an…
... br />
[code]
MAIN LD HL,50213 ; MAP START ADD
LOOP1 LD BC,8 ; SET THE COUNTER FOR ... THE LINE COUNTER
LD BC,32 ; SET THE COUNTER FOR ... /> LD BC,32 ; 32 TO ADD TO THE MAP ADDRESS
ADD HL,BC ... -
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' ; 4
ld a, (de) ; 7
ld (hl), a ; 7
hl, de
.dontcheckright
ld a, c ; A = largest
pop bc ... /> push bc
ld a, b
ld b, c
ld c, ... /> ex de, hl
swap_word
push bc
ld c, 0
Short Z80 QuizQ1) Which program gives different result ? A) XOR A ADD A,A B) XOR A ADC A,A C) SCF ADD A,A D) SCF ADC A,A Q2) What is the equivalent of NEG …
... HL
DJNZ LOOP
RET
B)
LD BC,10 ...
LD HL,60000
LOOP: LD (HL),C
INC HL
DEC BC ...
LD A ...FAST PIXEL DRAWINGI'm looking for the fastest way to put a pixel to the screen (on spectrum ofcoz:). Here is my own procedure (written in PASMO). But I don't how do it…
...
ld c,a
ld a,(bc)
ld b,(hl)
or ... b
ld (hl),a ...IM 2 interrupts and smooth scrolling - easy peasy!Okay, been fiddling around with IM 2 and have actually mastered (I think) how to use IM 2! Now I run my game Ragnar Revival in IM2 and use HALT to sy…
...
push hl
ld hl,16384
inc (hl)
pop hl
ei ...
ld bc,260 ;229*256+229, i.e 58853
ld (hl),229 ... : lsb,msb
ld (hl),0BAh
inc hl
ld (hl),088h
Pixel setting / general speccy codingi just started doing some cross-coding with the [url="http://www.bigfatpanda.fsnet.co.uk/z80.html"]Z80 SNA assembler[/url] and an emulator, and this …
... /> ld a, c
and 7
ld c, a
add hl, bc ...
ld b, (hl)
ex de, hl
ld ... a, (hl)
xor ...need help with speed optimization. this procedure draws a sprite with mask from memory onto the screen with x-coordinate in pixels. it doesn't shift sprites in realtime, it just uses …
... C
LD (HL),A
INC HL
POP BC
DJNZ DRAWMID ... /> OR C
LD (HL),A
POP BC ;restoring data needed ...Calculate screenaddressWho knows where the topic about the fastest screenaddressroutine is? I can't find it in a search.. The fastest routine was to load a large table of …
... space needed.
BC holds Y/X
LD L,C
LD A,(HL) ; first part of ... H
LD H,(HL) ; Fetch Hi-byte
LD L,A
RET ; HL holds screenaddress
Machine Code Sprites Example Code Using Char Based SystemBelow is my WIP code to do smooth screen wrapping sprites using char positions and offsets, as opposed to writing direct to a line (0-191) and shifti…
... br /> Spriteloop:
PUSH BC
CALL MoveSprite ... LD D,0
LD HL,gfx
ADD HL,DE ... Exit
; HL Contains Screen Address
; BC preserved
...IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... +3)
LD D,0
LD HL,gfx
ADD HL,DE
ld hl,0FE00h ;Building up a table with
ld bc,0FDh ;253 ... /> pp1:
ld (hl),C ; LD (0FE00h),FDh
inc hl ; repeate 253 times ...Smooth Color Masked Sprites using fast page flip on 48kHere is a quick demo of using char based sprites using the Page flip method: a) Background is copied to buffer b) Sprites drawn on buffer c) Buffer …
...
LD HL,BACKGROUND
LD DE,BACKGROUND+1
LD BC,1B00h
LD (HL),%01000111 ... />
LD HL,0FE00H ;BUILDING UP A TABLE WITH
LD BC,0FDH ;253 ...Smooth Masked Sprites using fast page flip on 48k Part 2Ok, After all the suggestions in Part 1, which were all excellent (Thankyou), I opted on the following: I have 2 x 6k Offscreen areas (Yes, that's …
... /> LD HL,BACKGROUND
; LD DE,BACKGROUND+1
LD BC,0C00h
prelp:
LD (HL ... ),%11111111
INC HL
LD (HL),%00000000 ...Smooth Screen Scrolling RoutineHi everyone, this is a follow up to the thread on smooth screen scrolling. As promised here is the code for the routine. It's pretty long and fairl…
... /> LD (HL),B
LD BC,1760
SBC HL,BC
POP BC
LD (HL ... /> LD (HL),B
LD BC,1760
SBC HL,BC
POP BC
LD (HL ...The incredible shrinking screendumpIn this topic I stated that I would be impressed if the screendump could be smaller than 37 bytes. [url="http://www.worldofspectrum.org/forums/viewt…
... , B 0
nline ld hl,table-1 ; Use JR value ... B-reg
prtab inc bc ; Start of tableprinting
... next byte in table
ld e,(hl) ; Fetch 'last' byte ... in table
prbyte ld a,(hl) ; Fetch byte for print ...Anyone help re-factoring a tile functionI had some excellent feedback for re-factoring my function that displays the colour for my screen tiles. Can anyone offer some help to improve the fu…
...
POP DE
POP BC
INC E
INC ... ,(HL)
LD (DE),A
INC HL
INC E
LD A,(HL ...Fastest way to write something to screen$Hi, I just got pasmo.exe and start playing with attr scrolling, well, not scrolling, just write different values to a block and see if I can introdu…
... sure about the push vs ld (hl),a.
NOTE: ... LD (OLDSP),SP
LD SP,base+len
LD BC,len/2
LD ... D,val1
LD E, ... PUSH DE
DEC BC
LD A,B
OR ... /> JR NZ,LOOP
LD SP,(OLDSP)
ENDM ; ...Programming MC : first stepsIsn't nice to collect all kinds of short routines to help making the first steps into MC for everyone who never touched MC? What I mean is mostly th…
... />
start ld hl,(23672)
ld (seed),hl ; RANDOMIZE equivalent
ld a,6 ... push hl ; save registers
push bc ; save registers
ld c,a ...Optimisation Needed! Is this the Fastest way to copy bytes from screen and back again?I have the screen address (say 0,0 i.e 16384) I want to copy 4 bytes wide by 32 bytes high from the screen to an area of memory. I then want to cop…
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 …
... hl,bc
jp c,next2
ld a,(bc) ;swap (bc),(de)
ld h ... /> ld (bc),a
ld a,h
ld (de),a
pop hl ;restore ...Spin save dissembly problemHey Dunny and others Spin dudes! There seems to be a small problem with the save dissembly function from the dissembler in Spin. This is the exact o…
... : push bc ; 26562 11ts
push de ; 26563 11ts
ld hl, l29699 ... ; 26564 10ts
ld (26511 ), hl ; 26567 16ts
ld hl, l29735 ...Problem with rotating procedureHi folks! I wrote a proc in z80 asm, based on: x' = x * cos (z) - y * sin (z) y' = x * sin (z) + y * cos (z) I used a precalculated table of sin a…
... /> ld hl,cosx
add hl,bc
ld e,(hl)
inc hl
ld d,(hl)
ld hl ... /> ld hl,sinx
add hl,bc
ld e,(hl)
inc hl
ld d,(hl)
ld hlIn Machine Code, what is the quickest way to sort bytes?I am playing around with some ordering of sprites, where I want to order them by vertical position. I used some Rodnay Zaks code to order some bytes…
... /> ld hl,numbers
ld bc,7
bubble ld (temp),hl ; temp = (hl)
again ld ... ix,(temp) ; ix=(hl)
res ...Pimp my code...Erm, this is just the result of a mental exercise - I wanted to repeatedly display a UDG but decided against using a ROM routine and UDGs! Any sugges…
... /> ld hl,#4000
ld b,#08
;
loop push bc
ld a ...
inc de
ld bc,#0100
ld (hl),a
ldir
pop bc
djnz loop
