-
LZ4 decoderI encountered the [URL="http://code.google.com/p/lz4/"]LZ4 compressor[/URL] a few weeks ago. Reading the [URL="http://fastcompression.blogspot.co.uk…
... not shadow BC, DE or HL.
unlz4:
ld b ... ; save destination pointer
ld e,(hl) ; read the low byte of ... (4T)
.getlength_nocarry:
ld a,(hl) ; re-read the byte (7T ... -
Copy 4Kb in Assembly?Here's an interesting problem: what's the best way to copy a block of 4Kb in assembly? The most obvious solution is to use [B]LDIR[/B]: [CODE] l…
... /> [CODE]
ld hl,SOURCE
ld de,TARGET
ld bc,4096
ldir ... bc
push de
push hl
ld (dest+1),sp
ld hl ... /> [CODE]
ld hl,SOURCE
ld de,TARGET
ld bc,4096+128*256 ... -
Nasty 'Gotcha' for multicolour timingI thought I would be better developing my multicolour routine on the 48K first, being the slowest, so it would then be sure to work on the 128K varia…
... +2A. I've used LD (nn),HL , then I've used ... Now whether you use DE, BC, IX or IY, the instructions ... prefix byte longer than using HL. There's even a ... duplicate of the command using HL, again with the prefix ... can do LD (nn),IX followed by LD (nn),HL since the ... -
z88dk and im2I set up a minimal IM2 mode so I can draw sprites for a laff [code] #include <string.h> #include <stdio.h> #include <im2.h> #include <stdlib.h> #in…
... />
LD BC,255
LD DE,04000h
LD HL,37000
< ... /> #asm
LD BC,37000
LD L,0
{
#asm
LD BC,37000
LD BC,255
LD DE,04000h
LD HL,37000
... -
Troublesome routine, help needed!Having problems with this routine, it basically fires a rocket up the screen, but refuses to detect collisions. I'm using attribute blocks for detect…
... into print string
push bc
call print ;call the ... /> call 5633
ld de,rktdat
ld bc,33
call 8252 ... HL, HL
ADD HL, HL
ADD HL, HL
ADD HL, HL
ADD HL, HL
LD DE ... -
A "generic" loader for +3(e)I've made this loader for 128k games in +3DOS. [CODE]dos_open equ 262 dos_close equ 265 dos_abandon equ 268 dos_read equ 274 dos_write equ 277 dos_s…
... disable cache
ld de,0
ld hl,128
call dos_set1346 ... file
ld bc,$0501
ld de,$0002
ld hl,fichero
... br /> ; finsi
ld bc,5
add iy,bc ; iy points to ... paginar:
di
ld bc,32765
ld (BANKM),a ; BANKM is ... -
Math Quiz - MultiplicationThe topic is fast multiplication routines, from 8x8 to 32x32 and all points in between. These functions sit underneath floating point libraries, gen…
... /> ld c,b
ld b,0 ; bc = MSW(HL * E)
ld d ... ,l
ld e,b ; bc = LSW(HL ... -
Ghosts n' Goblins loaderI'm trying to put Ghosts n' Goblins onto a +3 disk but struggling to understand the mc loader. Basic loader [code] ink 7 : clear 25000 : load "" cod…
... /> 65224: LD HL,65240
65227: LD BC,236
65230: LD A,(HL)
LD (HL),A
65234: INC HL
65235: DEC BC
65236: LD A ... BC
65251: ADD HL, DE
65252: LD SP, HL
65253: POP HL ... -
Scrolling Bi-Colour Engine for 4-Player GamesJust putting this code up for people to have a look at. Far from finished. Should simply compile and run a bit of a demo. Only good for 128K and +…
...
ld c,a ;bc = y*32
ld hl,22528
add hl,bc ;hl = address ... /> ld hl,char_address
add hl,bc ;hl = row in table
ld e,(hl)
inc hl ...
ld d,(hl ... -
Double-Buffer ScreenFor my Alien Breed Speccy re-write I decided to use a Double Buffer (DB) or 'Back Screen' to draw all the game action onto, before shuffling the whol…
... ]
.org 31144
ld hl, 25000 ;Start of DB Screen ... Counter
loop1:
ld bc,32 ;BC is counter for block copy ... 3
ld (cfield),a
ld a,80
ld (dreg),a ... -
SBC or ADDIs this dangerous/bad practice thing to do..... I want to subtract 64 from a number, but to save a few bytes can I just add (65536-64) 65472 to the…
... ]
LD HL,32768
LD BC,65472
ADD HL,BC
LD (test),HL
RET ... />
LD HL,32768
LD BC,64
SBC HL,BC
CCF ; sometimes ... it need this....
LD ... -
Problem with DivIDEHi There is a problem on ZX-Spectrum +2 (Grey Model) + DivIDE 2k14 here is video with problem [URL="http://www.youtube.com/watch?v=nIQboFo7Epc"]h…
...
i_04
ld hl,#5818
i_02
ld bc,#001f
in ... /> ld (hl),e
inc hl
djnz i_03
ld bc,#0018
add hl,bc ...
ld a ... -
Fuse bug? Strange T state countingI was testing delay routine presented [URL="http://www.worldofspectrum.org/forums/showthread.php?p=214851"]here[/URL]. I'm reproducing its listing: …
Currah ?Speech channelIt seems to me that it would be nice to be able to send words to the ?Speech with PRINT #5;"Speak English to me, Jimmy" or some such. There really i…
... bc
push de ; the
push hl ; registers
ld b ...
ld a, (hl) ; get allophone
ld hl, (65362) ; address buffer
ld (hl), a ... details
ld (65364), hl ; say it now
ld bc, 20
Hooky - hook ZX ROM and rewire RST and NMI to RAM - rantThis is a rather long rant. Not for short tempered. :) The objective is to hook into RST "vectors" and NMI on a Spectrum without affecting the normal…
... HL ; HL=HL-1 (hl back to 0xffff)
0x11F0 EXX
0x11F1 LD (5CB4),BC ... /> 0x1200 LD (5CB4),HL ; overwrite BC' with "real HL" (where ... mem test ended)
0x1203 LD DE,3EAF
0x1206 LD BC ... ,00A8
0x1209 EX DE,HL ; HL=3EAF, ...Problem Reading the KeyboardHi Folks, I'm working my way through Toni Baker's rather good book and thought I'd write some code to scan the keyboard and store the results so tha…
... /> LD BC,040d ;40 bytes to copy
LD DE,_oldKeyStates ;Destination
LD HL ...
LD HL,_currentKeyStates ;Where to store the key data
LD BC,0x08 ...Simple text scrolling routine...I'm having trouble writing a very simple text scroller, the idea is to use the ROM printer routine to print 32 characters each time the routine is ca…
... 5633
point ld de,dat
ld bc,32
call 8525 ...
ret
attr
ld hl ... ,23264
ld b,64
loop ... /> inc a
ld (hl),a
inc hl
djnz loop
Help needed with a bit of code...My minds gone blank again I'm afraid, I'm having trouble with this routine that loads variables into memory then calls the corresponding routine. Th…
... /> ld hl, cor
ld de,adds
loop
ld a,(de)
ld ... /> inc de
;ld a,(hl) ;hl stores variables
;now i ... br /> push de
push bc
caller
call 56003 ... to be called
pop bc
pop de
pop ...Return to basic from sna created by Z80 compilerHow can I go back to basic when running sna created using Z80 Assembler ([url] http://www.worldofspectrum.org/utilities.html#crossass [/url])? For e…
... /> ld hl,16384
ld de,16385
ld bc,6143
ld a,255
ld (hl ... ),a
ldir
skok: ld ...Double height text...<p>Is here any good routines for printing a font double height?</p><p>I've concocted this ridiculous routine but I'm sure it can be done much better.…
... /> ld (char),a
push hl
push de
push bc
pop bc
pop de
pop hl
inc de ld hl,x1 ... /> inc (hl) ld hl,x14+1
inc (hl) ld hl,x15+1
inc (hl); ld hl,x16 ...ZERO Emulator - BugsI have been using Zero emulator to experiment a few routines in assembly, since it has a somewhat usable debugger. However I believe I found a few b…
I have been using Zero emulator to experiment a few routines in assembly, since it has a somewhat usable debugger.
However I believe I found a few bugs, some in "zero" application, and some on emulation itself.
The following example ...Drawing some spritesI figured I want to draw some sprites. My target was to do a 16x16 masked sprite. There's no clearing here, just drawing the sprites. My first ite…
... br /> ld d, 3 (iy)
ex de,hl
add hl, bc ; add ... x offset
ex de,hl
ld ... br /> add hl, bc ; add x offset
ld a, (hl) ; load pixel ...WANTED Machinecode Routine for Paging in Betadisk TR-DOS v5 ROMI try to build a small MCode-program which writes the TR-DOS-ROM v4 / v5 to RAM adress 40000 an up. It´s working on TR-DOS v4 / Betadisk 48k: C…
... an additional PUSH HL for RET
PUSH HL ;Put the ... 40000:
LD HL, 0
LD DE, 40000
LD BC, 16384
... / Betadisk 128k:
LD C,0 ;Set DOS Routine ... 40000:
LD HL, 0
LD DE, 40000
LD BC, 16384
...Mr. Jido makes some noiseA little something to analyse and discuss for you. [code] ORG 60000 ; RND Generator: RND LD HL,EARTH LD A,(WIND) ADD A,L LD …
... ,(HL)
LD (FIRE),A
LD HL,WIND
INC (HL)
LD E,(HL)
LD HL ... /> LD B,0 ;throw away 256 things
DESTROY PUSH BC
CALL RND
POP BC
DJNZ DESTROY
RET< ...Text scroller and custom fontYesterday I was testing this text scroll routine taken from Jonathan Cauldwell's Intro Maker (labels have been inserted to allow partial code relocab…
... />
LD HL, FONT
LD (23606),HL
LD DE,L_35413
LD BC,00001
BC
DJNZ L_35420
LD HL,(L_35489)
LD A,(HL)
POP HL
Let's copy buffers!Figured I'd do some double buffered graphics, so I can render for several frames before displaying stuff. Yes, I mean on a 48k speccy, so no 128k spe…
... af
ld bc, #12
add hl, bc
ld sp, hl
pop af ... /> push af
ld bc, #12
add hl, bc
[/code]
[img ...Basic Screen Shadow QuestionHello, I've been porting a game to the Spectrum from another platform. So far so good and I have per pixel screen scrolling working really nicely …
... or c
ld bc,0x7ffd
ld (0x5b5c),a
... ld hl, attrib_data
ld b, %01111000
ld de, 768
_loop:
ld (hl ... br /> fill_screen:
ld hl, screen_data
ld b, 0x01 ; Value ...Flicker-free animationTrying to create flicker-free screen update, but... Where I'm wrong? [url="https://dl.dropboxusercontent.com/s/pfywhfejfmwt2zq/test_128.sna"]Snaps…
... /> draw_keep:
ld hl, SCREEN
ld de, SCREEN+1
ld bc, CYCLES-1 ...
ld a, (keeper)
xor %0010
ld (swap_video+1), a
ld bc, BANKS
out ...How would you do a negative image ?So I want to invert a Speccy bitmap. What would be the fastest and easiest way to this ? I've been using this a lot but I can't see how I could achi…
... HL to DE.
ie
LD HL, 16384
LD DE, 51444
LD BC ...
