-
So you want to make a cardgame......but you haven't got a good deck to display. Well here is a fully relocatable routine that will do the job for you. Place the code anywhere in me…
A fast DRAW routineI was investigating how to speed up the line drawing for the [URL="http://www.worldofspectrum.org/forums/showthread.php?t=20225"]BASIC compiler[/URL]…
... br />
exx
add hl, bc ; error += dY
... While loop
exx
add hl, de ; error -= dY
exx
add hl, bc ; error += dX
a
ld de, (SCREEN_ADDR)
add hl, de ;; ...Add quite a lot of items to my site and a Make an Offer Button.Hi everyone, I asked for some feedback on my site a month or so ago ([URL="http://www.worldofspectrum.org/forums/showthread.php?t=33521"]link[/URL]).…
... link[/URL]). I got a few constructive comments and some ... One of them was to add a [B]Make an Offer[/B ... I managed to list a couple of hundred speccy ... , with (at a guess) another 200 still to add.
Anyhow please feel free to have a ...A quick newbish questionI'm reading through 'mastering machine code on your spectrum',as kindly posted by Mr bert on this forum. Correct me if I'm wrong from what i read,bu…
... pairs like Hl hold 2 bytes or a word (16bit ... A' register,but can use any single register with it ie ADD A ... ,C,ADD A,D but not for example ADD D,A,or ADD ... B,C.Or you can use ADD HL, ... pair ie DE.
ADD Hl,DE together would still be ...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…
... (HL),A ; poke flipped byte
ADD HL,DE ADD HL,DE
ADD IX,DE ADD IX ...Converting an integer arbitrary large binary number into a printable decimal formThis was asked a long ago at the comp.sys.sinclair newsgroup. At that time, I came up with a solution by extrapolating the classic algorithm of suces…
... c,NoAddHi
add a,30h
ld (hl),a
NoAddHi and 0fh ... /> add a,3
and 0fh
ld c,a
ld a,(hl)
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…
... but to save a few bytes can I just add
( ... BC,65472
ADD HL,BC
LD (test),HL
RET
ADD and one to SBC,
add.
Sometimes the ... SBC needs to have a CCF to keep the ...I don't think I'm getting the $22AA Pixel-Add rom routineDear all, I'm misunderstanding how the PIXEL-ADD rom routine works. My code... [code]ld b,175 ld c,1 call $22AA ld (hl),a ret[/code] So…
... m misunderstanding how the PIXEL-ADD rom routine works.
... /> call $22AA
ld (hl),a
ret[/code]
HL containing $6400 and the ... bit 6 (does this mean A=64?)
... So I'm a bit confused why the code ...A sped up pixel-shift routine for 1-byte–wide spritesHere’s an optimized (for speed) real-time sprite shifting routine for sprites that are one byte wide. It uses no memory variables for storage of inte…
... C
ld (hl),a ;place it on screen ... /> ld a,(hl)
xor b
ld (hl),a ;place ... a,l ;else, load A with L
add a,32 ;add ... 32 to it
ld l,a ... jr c,msl_shift_done ;if ADD A,$20 results in overflow, ...Copying a single character from one place to another?[code] ORG 33000 LD A,8 LD HL,16384 LD BC,256 LD DE, 18432 LOOP: PUSH AF LD A,(HL) LD (DE),A ADD HL, BC POP AF DEC A JR NZ,LOOP REST […
... 33000
LD A,8
LD HL,16384
LD BC ... AF
LD A,(HL)
LD (DE),A
ADD HL, BC
POP ... AF
DEC A
JR ...A Neat Redefine Keys RoutinePreviously, I’ve only shared this routine with a couple of people via PM, but I’ve now decided to make it public. I optimized it for size, so it uses…
... ;pair, such as HL and zeroize the high byte ... /> ; ld (control_count+1),hl ;inject # of bytes to ... to the next
add ix,de ;table row< ...
ld hl,dummy_key ;point HL to the code of ... key
ld (hl),a ;now HL points to (dummy_key+BC), ...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.…
... br /> loop: ld a, (de)
ld (hl), a
inc h ...
ld a, c
add a, %10000000
ld c ... a, c
add a, %00000001
ld c, a
write: ld (hl), ... br /> loop2: ld a, (de)
ld (hl), a
inc h ...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…
...
ld e, a
add hl, de
inc hl
ex af ...
ld e, a
add hl, de
inc hl
ex af ... root
push hl
ld e, a
add hl, de
push ...Assembler code from tutorial, problem!I was wondering if anyone could help me decipher this z80 assembler code? ORG 60000 LOAD 60000 EA60 21BCEA LD …
... A,80H ;set top bit in A
EA65 86 ADD A,(HL) ;add ... previous digit
EA66 3C INC A ; and ... /> EA67 77 LD (HL),A ;replace digit in memory< ...A ZX81 Games QuestionHi All, I'm looking for Sinclair branded ZX81 software titles to add to a collection. I have a number of other ZX81 titles available to swap/sell fo…
... software titles to add to a collection. I have a number of other ...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…
... this is the source for a Z80 emulator. Forgive my ... know if it's a Z80 emulator for Spectrum ... 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…
... a,l
ld l,h
ld h,0
add hl,hl ...
ld de,scrtable
add hl,de
add a,(hl)
inc hl ...
ld h,(hl)
ld l,a ... ld a,(de)
or (hl)
ld (hl),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…
...
rrca
add a,40h
ld h,a
ld ... ,bits
add a,c
ld c,a
ld a,(bc)
ld b,(hl)
or b
ld (hl),a ...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 …
... hl, lineptrs
add hl, de
add hl, de
ld e, (hl)
inc hl ... /> add hl, de
ex de, hl
ld hl, pixelmsk
ld a, c ... , a
add hl, bc
ld b, (hl)
ex de, hl
ld a, (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 A,8
ADD A,L
LD L,A
LD A,(HL)
LD (DRAWE1+1),A ...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…
... ,0
LD HL,gfx
ADD HL,DE
ps01 ... br /> LD B,A
ps0:
ADD HL,DE
... br />
ADD A,(HL) ; Add the contents of HL to A
; So ...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] ; ***********…
... ,0
LD HL,gfx
ADD HL,DE
ps01 ... br /> LD B,A
ps0:
ADD HL,DE
... br />
ADD A,(HL) ; Add the contents of HL to A
; So ...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 E,A
LD D,0
ADD HL,DE ; Add onto GFX ... =FA0AH
ADD A,(HL) ; ADD THE CONTENTS OF HL TO A
; SO AT ...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 E,A
LD D,0
ADD HL,DE ; Add onto GFX ... =FA0AH
ADD A,(HL) ; ADD THE CONTENTS OF HL TO A
; SO AT ...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…
... for clipping tile
ADD HL,BC ;ADD ON A DISP. IF CLIPPING BLOCK ...
ADD HL,BC ;HL = ADDRESS OF PRESHIFTED BLOCK
LD A,(BLFLAG ... BC,0
ADD HL,BC
LD A,(BLFLAG)
OR ...Index register subtractionHi, Just wondering if there a way to perform SBC HL,BC on the IX or IY registers. I can't find an op code for it, and my assembler doesn't recognise…
... wondering if there a way to perform SBC HL,BC on the ... doesn't recognise it as a valid instruction, so I guess ... . It seems strange however that ADD HL,BC can be prefixed to ...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 (HL),A
PUSH AF
LD A,31
ADD A,L
LD L,A
POP AF
LD (HL),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…
... />
LD A,L
ADD A,32
LD L,A
ld (hl),a
inc hl
ld a,(de)
inc ... NZ,DRAWBEG
LD A,L
ADD A,32
LD L ...Amazon charge a fortune to use Z-SHOPSI sold a Dr Who vhs video ( The Face Of Evil ) using Amazon just to see how much they charge for using their service, I sold the video for £7.99…
I sold a Dr Who vhs video ( The ... £7.99 and Amazon add on a set price for postage which ...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…
... add hl,hl
rla
jr nc,fin21
add hl,de
adc a ... c,d
add hl,bc
adc a,0
... br /> ld a,128
ld hl,(xr)
add a,h
... ,a
ld a,96
ld hl,(yr)
add a ...
