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Routine for clearing screenI was looking for a 'nice' way of clearing a screen of graphics in Z80. After a ridiculous amount of time mucking around, this is the best and most …
... ]
START
ld hl,16384
ld bc,6144
ld de,(PRT_CHR)
SCREEN_CLEAR_LOOP
ld a,(hl)
and e
ld (hl),a
inc hl
dec bc
ld ... -
28-character wide multicolour(ish) on 48k SpectrumLong-time lurker here... I've always been interested in rainbow effects on the 48k Spectrum, mainly from a perspective of "Just what [I]would [/I]ha…
... bc
push de
push hl
PUSH AF
LD (VALSP ... ),SP
LD SP,HIRES
LD BC ... ,0219H
DELAY DEC BC
LD A ... -
Byte-order backbufferThis is a tool for Z80 coders who wish the Spectrum screen had a serial layout. It runs as an interrupt mode 2 service routine and uses POP and PUSH …
... byte of the screen
ld hl, $ + 9 ; set ... no stack available)
ld (endcall), hl
jp blit ... chunk * 2048)
ld hl, $ + 9
ld (endcall), hl
jp blit< ... pop bc
pop de
pop hl
ld sp ... -
What's wrong with this code ?OK, working my way through Jonathan Cauldwells 'How To' tome and I can't get the following to run in either spin or basin. ( iused the assembler in b…
... up the graphics.
ld hl,blocks ; address of user-defined ... /> ld hl,21+15*256 ; load hl pair with starting coords.
ld (plx),hl ... his new coordinates.
ld bc,63486 ; keyboard row 1-5 ... -
CMWC random number generator for Z80Seeing the interest regarding the [URL="http://www.worldofspectrum.org/forums/showthread.php?t=23070"]Xor-Shift random number generator for Z80[/URL]…
... /> ld b,0
ld c,e
ld hl,table
add hl,bc
ld c,(hl) ; y = q ... /> ld l,b
sbc hl,bc ; t = 255 * y
sbc hl,bc ... -
Jelly-Vision!As threatened in the "'Spectrum Play' Error" thread, here's a ruff'n'reddy interrupt driven full screen wobbling routine which has no practical use w…
... /> ld a,(hl)
cp $0e
jr z,INSCROLL
push bc ...
ld bc,6144-256
jr nz,MOVEUP
MOVEDOWN: ld hl,16384 ... -
Hep needed with a bit of code...I've written a bit of code to make a character move across the screen, but the counter stops at 29 when the 3 lines to delete the characters trail ar…
... ; ????
ld hl, 63289
dec (hl)
dec (hl)
ld a,(63289 ...
call 5633
ld bc, 10
ld de, 63290
call ... /> ret
prb: ld a,(63289)
ld (63298 ),a
call ... -
40 Column Printing RoutineI've written a 40 column printing routine, which I'd like to share... It's my first piece of 'public' code so go easy on me! I don't think it is a…
...
nextshift push bc
ld b,8
ld hl,scratchspace
nextshiftline ...
nextovershift push bc
ld b,8
ld hl,overscratch
nextovershiftline ... -
merging bytesPicturing three bytes with their bits identified by letters to make the visualisation easier, what's the best way to perform this transformation? [co…
... /> push af ;A=ABCDEFGH
ld bc,(COORDS) ;eg.B(y)=50 ... , C(x)=11; BC=$320B
call $22aa ; ...
ld (hl),a
inc hl
[color=red] ld a,(hl) ;ld a,b ... -
next pixelI searched the "Discussions" groups for the phrase "next pixel" and got no matches - and removing the quotes it discards the "next" and just searches…
... /> ld hl,$4000
ld de,$4000
ld bc,0
pixrow: ld (hl),$ff ... /> rrc c
add hl,bc
pop bc
jr pixrow
BeepFX ProblemHi All, I'm currently trying to integrate the BeepFX engine in my 100% Assembler Game and it plays the sound fine, but then plays the sound again, a…
... ld c,a
add hl,bc
add hl,bc
ld a,(hl)
inc hl ...
ld h,(hl)
ld ...multi-scroll m/c subroutine for BASICArising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. whe…
Arising from recent posts, here's a scrolling routine that will manage multiple left/right scrollings for any (sensible) line width or step; (ie. where width isGraph Plothi! please, help with code: [PHP]For x=-100 To 100 For y=-100 To 100 If (x/2-25)*(x/2-25)+(y-50)*(y-50)<200 Or (x/2+25)*(x/2+25)+(y-50)*(y-50)<200 th…
hi! please, help with code:
[PHP]For x=-100 To 100
For y=-100 To 100
If (x/2-25)*(x/2-25)+(y-50)*(y-50)Optimisations in Exomizer Z80 decrunch codeThis is the 163 bytes old code (simple and optimized): [CODE] ld iy, exo_mapbasebits ld a, 128 ld b, 52 push de exo…
... /> push hl
ld h, d
ld l, e
sbc hl, bc ;hl=origin ... (sp), hl
ld d, h
ld e, l
sbc hl, bc ;hl=origin ...Elliptical ChallengeSubsequent to the recent "Graph Plot" thread, I wrote this general purpose ellipse drawing routine which will plot (although it doesn't actually use …
... ;end_calc
ld hl,(STKENDO)
ld de,STKSTOR
ld bc,20
ldir ... /> NOTNEG: push bc
ld hl,STKSTOR
ld de,(STKENDO)
ld bc,20
How do you restrict this routines actions?I'm trying to plagiarise a piece of code I came across in the 80's, but seem to be banging my head against a brick wall! The routine fades the scree…
... /> l_b798: ld hl, 22528+32
l_b79b: ld a, (hl)
ld b, a ...
l_b7ca: ld (hl), a
inc hl
ld a, h
bc
jr l_b798
l_b7d8: ld bc, 511
l_b7db: dec bc
ld ... jr nc, l_b7db
pop bc
djnz l_b7d5
call ...Works in Fuse & SpecEmu, not ZXSpinI decided that I wanted to change the scroll routine which I was using for compiling the Trailblazer maps, as I'd just copied it out of Andrew Hewson…
... rst $10
ld bc,10
ld de,STARS
call ... ld a,8
ld bc,$0c
PATLOOP:
ldir
ld bc ... ,$0c
and a
ex de,hl
sbc hl,bc ...Idk>le me browsing through some game's code >..... [code]61A8 F5 push af 61A9 3EFF ld a,FF 61AB D37F out (7F),a 61AD D33F ou…
...
623E 21E462 ld hl,62E4
6241 011A00 ld bc,001A
6244 ... 1818 jr 625E
6246 21E462 ld hl ... ,62E4
6249 011A00 ld bc,001A
624C ...Machine code assistance please #1Dear all, Learning the ropes here, so please excuse these odd questions which may seem simplistic to you learned lot. This routine is placed at 33…
... /> [code]
ld l,155
ld c,200
ld a,c ...
add a,l
ld c,a
ret
[code]
ld hl,0
ld bc,0
[/code]
Struggling with this routine... Any ideas?I'm trying to write a routine that plots 3 pixels to decrease the energy bar in the top right corner by 5 units, but it just wont have it! There mus…
... 5
push bc
loop1 ld hl,51993 ;address energy level ... is stored
dec (hl) ;decrease ... bright
ld (23695),a ;set colour
ld a,(hl) ;load ... a with energy level
ld b, ...Strider II (and others) + 3 disk versionsHello everyone, I've been working on converting some games to be able to load them from the +3 floppy. I started with single load games but now Im i…
... /> ld hl, 23296 ;backup to
ld de, 49152 ;page 6
ld bc, 1023 ... ;
ldir
ld hl, 50180 ;copy disk ... /> ld hl, 49152 ;recover data
ld de, 23296 ; from page 6
ld bc ...How to write self-relocating code using Pasmo?With z80asm, I can write code like this: [CODE] org 0 ; a total lie, but makes the reloc sums work .dest: equ …
... in HL
ld de,.dest ; target address of relocated code
ld bc ... /> add hl,bc ; ...but now in HL relative to entry addr
ld bc,.reloc_len ...30-column 8x2 multicolor (even in 48K)I don't recall any 8x2 multicolor routine for 30 columns that would work on all Spectrum models (including the Spectrum 48K), so I decided to write i…
... LD HL,nn
LD DE,nn
LD BC,nn
EXX
LD HL ... ,nn
LD DE,nn
LD BC ... ,nn
LD IX,nn
LD ... LD HL,nn
LD DE,nn
LD BC,nn
PUSH BC ...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…
... BC ;save C ; moved up
FLIPH2 LD A,(HL) fliph2 LD A,(HL ... push HL IX BC
PUSH IX ;
PUSH BC ;
LD DE,#1800 ; HL ...MGT MOUSE - exist really ?I read disassembly of +D rom/ram code and from address #2249 is routine for read MGT MOUSE ports. I can't find any info about "MGT MOUSE". Exist real…
... necessary.
2249 TEST_MOUSE LD BC,#03FF The MGT mouse port ... /> 2255 LD HL,#228B,SIGN_MOUSE
2258 PUSH HL
2259 LD HL,#2275,MOVE_VERT ...Can a guy that traveled on the short bus learn machine code...Hmmm So after some soul searching I figured it was time to finaly nail spectrum machine code. Its so frustrating to sit infront of a basic listing w…
... = LD A,
06 = LD B,
0E = LD C,
16 = LD D ... = LD E,
26 = LD H,
2E = LD L,
01 = LD BC,
11 = LD DE ... ,
21 = LD HL,
MC LPRINT 23681Having problems with this routine to print large on the screen using LPRINT, it works ok in BASIC, but cant seem to get it to loop for some reason in…
... cols ;fill attributes
ld hl,72 ;start of address to ... loop ld (23681),hl ;poke address with hl
push hl
push bc
pop bc
pop hl
inc hl ;increase hl
... open channel
ld de,dat
ld bc,16
call ...JSW2 - Game Loader DifferencesThere are three official releases of JSW2. I'm not counting the 'JSW2-128' version here as far as I'm aware this was not in any way 'official' as it …
There are three official releases of JSW2. I'm not counting the 'JSW2-128' version here as far as I'm aware this was not in any way 'official' as it incorporates a built in cheat mode. Feedback on this point is appreciated. To quote the readme:
SCREEN$ bug fixI've been using the SCREEN$() function recently for reading data off the screen rather than taking up space with an array and I got fed up with the s…
... hl
inc hl
call $33b4 ;STACK_NUM row
pop hl
ld bc ... ,10
add hl,bc
call $33b4 ...
