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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…
...
sbc hl, de
ld e, c
add hl, de
cp (hl) ; cp ...
sbc hl, de
ld e, c
add hl, de
cp (hl) ; cp ... hl, de
ld e, c
add hl, de
ex de, hl
pop hl
Z80: ABS(HL) functionI must be very tired but I cannot get my head around whether this function provides a correct implementation of a ABS function for a signed 16-bit va…
... /> RET Z ; Already positive
LD A, H
CPL
LD H, A
LD A, L
NEG ...
LD L, A
HL, DE with HL containing 0 and DE the input value ...LINE-routine and other nice pieces of codeThe line-topic came in the end with a nice piece of fast coding. I think that there might be more of these routines out there (where-ever-u-r). Isn…
... through the program
.......LD DE,0
.......JP MAIN ... B2.....INC DE
B1.....INC DE
MAIN...LD A,(DE) ; ... .......LD L,A ; HL points to highbyte (4)
.......LD H,(HL) ... ; fetch highbyte (7)
.......JP (HL) ; jump ...Z80 Emulator Source?Found a link to this on comp.sys.amstrad.8bit. i havent been with the discussion long but supposedly this is the source for a Z80 emulator. Forgive m…
... : ld a,(de)
ld l,a
ld h,21h
add hl,hl
add hl,hl ;hl ... =84xxh
jp (hl)
How to get Grahics to wrap vertically around the screen?I am using the following code to draw an image to the screen. First I use HL to contain ROW and COLUM I then call the MapScreenFunction As I draw m…
... hl,hl
ld de,scrtable
add hl,de
add a,(hl)
inc hl
ld ... h,(hl ... )
ld l ...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 hl,58880 ;Building up a table with
ld de,58881 ;pointers ... : 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 hl, lineptrs
add hl, de
add hl, de
ld e, (hl)
inc hl
ld ... d, (hl)
ex de, hl ...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 …
... /> LD HL,(SPRADR) ; taking precalculated screen address where to draw sprite
LD DE ... /> LD A,(HL)
OR C
LD L,A
LD A,(DE)
LD ...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…
... /> LD HL,gfx
ADD HL,DE
ps01:
LD E,72
LD ... /> PChar:
LD A,(DE)
LD (HL),A
INC DE
INC H ...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] ; ***********…
... /> LD HL,gfx
ADD HL,DE
ps01:
LD E,72
LD ... /> PChar:
LD A,(DE)
LD (HL),A
INC DE
INC H ...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), E
INC HL
LD (HL), D
INC HL
POP DE
LD (HL ...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,0
LD DE,16
ADD HL,DE
LD (hl3a+1),HL
LD HL,0
LD DE,16
ADD HL,DE
LD (hl3b+1),HL
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 A,(DE)
OR (HL)
LD (HL),A
INC DE
LD BC ... /> LD A,(DE)
OR (HL)
LD (HL),A
INC DE
LD BC ... /> LD A,(DE)
OR (HL)
LD (HL),A
INC DE
dmsmith
September 2004
Development
Jack The Nipper 2 Masking ... HowI understand masking i.e. ld a,(de) ; Get Mask and (hl) inc de ld a,(de) ; Get graphic or (hl) But how on Jack the nipper did they get the main ch…
I understand masking
i.e.
ld a,(de) ; Get Mask
and (hl)
inc de
ld a,(de) ; Get graphic
or (hl)
But how on Jack the nipper did they get the main character to go Behind the scenery?Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... LD A,(DE)
NOTDIRTILE PUSH HL
LD (HL),A
INC L
LD (HL ... /> PUSH DE
LD DE,32
ADD HL,DE
POP DE
...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…
... ,(HL)
LD (DE),A
INC HL
INC E
LD A,(HL)
LD (DE ...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: This ... />
LD (OLDSP),SP
LD SP,base+len
LD D,val1
LD E,val2
LOOP
PUSH DE ...
DEC BC
LD A,B
JR NZ,LOOP
LD SP,(OLDSP)
ENDM ; ...Best method for sprite collision detectionHi, I have been trying to incorporate collision detection into a sprite routine I writing. The following is what I have come up with so far: POP D…
... /> POP DE ; e=mask, d=sprite image
LD A,(HL) ; hl = screen ...
EXX
INC (HL) ; increase if there is a ... br />
NC0:
LD A,(HL) ; draw sprite as normal
OR D ;
LD (HL),A ;
INC L ;
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 h,b
ld l,c
or a
sbc hl,de ...
jp c,next1 ;loop until lohi
ld l ...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 de ; 26563 11ts
ld hl, l29699 ; 26564 10ts
ld (26511 ), hl ; 26567 ... ix, de ; 26656 15ts
[/CODE]
ld (nnnn), hl has null ...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 d,(hl)
ld hl,(x)
call mult22
ld (xc),de
ld ... /> ld d,(hl)
ld hl,(y)
call mult22
ld (yc),de
;----------------------------------------------------------------------------
ld de ...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…
... #8000
;
ld hl,#4000
ld b,#08
;
even ld a,#2a
jr ... cpy
odd ld a,#54
jr cpy ... hl
pop de
inc de
ld bc,#0100
ld (hl), ...Screen LoaderCouple days ago i find very interesting loader routine in ex Yugoslavia magazine "Svet Kompjutera" from january 1987. Authors of article, calls this …
... /> LD HL,49152
LD (HIL),HL
LD DE,16384
LD (DIL),DE
LD A ... LD HL,(HIL)
INC HL
LD (HIL),HL
LD DE,(DIL)
INC DE
LD ... KRA LD HL,RP
LD (RRR+1),
Pegaz
August 2006
Games
Pixel Explosion CodeJust a little snippet to cause explosive effects. It uses table lookups for the screen address, and can handle up to 32 pixel particles. A particle…
... get_screen_address_and_draw ; hl has screen address
madp_dec
ld de,8
ld a,(de) ; Get graphic
xor (hl) ; xor with screen
ld (hl),a ...Urgent Help needed to fix this: calling all machine code gurusI am currently trying to write tutorials on the amazing Orfeus music composer by Proxima which allows you to do multi channel music through the beepe…
... /> l88c9: ld a,(hl)
ex af,af'
ld a,(de)
ld (hl),a ...
ex af,af'
ld (de),a ... de
ld a,(hl)
ex af,af'
ld a,(de)
ld (hl),a ...Mode 2 Tile Editor SourceA Timex Mode 2 Tile Editor incorporating a byte mirror table. The compiled version is available in the CSSCGC 2008 collection from the WoS archive. …
... /> ld de,57344 ; second 128 tiles
cpstart:
ld hl,18432 ... /> ld de,$0000 ;
ld e,a ;
ld hl,mirror_tbl ;
add hl,de ;
ld a,(hl ... /> m_chan: ld hl,$7800 ; first address after second screen area
ld de,($5C4F ...RFC: 64 column font codeIn BASIC, type CLEAR 49999 then import the code at 50000. Then type RANDOMIZE USR 50000. This will create a new channel and attach stream #4 to it. A…
... /> ; in HL
ex de,hl ; store the offset in DE
ld hl,$5c10 ... /> add hl,hl ; multiply
add hl,hl ; by
add hl,hl ; eight
ld de,font ... -$80 ; offset to FONT
add hl,de ; HL ...Currah MicroSource emulationIt appears to be impossible to emualte the MicroSource in software on the ZX Spectrum SE as hardware polling is required. The following patch is not …
... hl ;
ld (hl),$19 ;
ld hl,uS_patch ; source
ld de,$18fe ; destination
ld ... hl ;
ld (hl),$18 ;
ld hl,ZX_patch ; source
ld de,$18f3 ; destination
ld ...
