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Character Based SpritesHi, I'm working through Jonathan's excellent guide to writing games, and have mastered the animation of single UDGs. Before or move onto Pixel…
...
call draw_tile
pop de ;get screen position back
call ... screen
ld (de),a
inc e
inc hl
ld a,(hl ... /> ld b,144
loop2
inc hl
djnz loop2
pop bc ... -
Help needed with MIA software with custom (?) loaderHi, I've got into my hands recently a bunch of Polish educational software which are unknown MIA on WOS. I believe they are protected with some…
... br /> 0x5CD6 LD BC,1800
0x5CD9 LDIR ; Fill screen with random ... (ROM)
0xEAE6 LD HL,053F ; SA/LD-RET in ROM (ROM ... IX (source address)
0xEB79 POP AF ; Restore AF
... -
2x2 tile to attribute blocksHow do you go about converting a 2x2 tile to 16 x 16 attributes? Heres an example of the tile data I'm wanting to enlarge. [code] defb 255, 25…
... enlarge
LD HL,22528 ; screen address
LD A,255 ; ... in
ADD HL,BC
POP BC ; recall the count< ... -
2x2 tile to attribute blocksHow do you go about converting a 2x2 tile to 16 x 16 attributes? Heres an example of the tile data I'm wanting to enlarge. [code] defb 255, 25…
... /> LD BC,8
ADD HL,BC ; move screen address along 8 bytes
POP BC ; recall ... -
Proportional fontsI've been doing some proportional font drawing, purely on C level at the moment, but it's orders of magnitude slower than I'd want it to be. It's sti…
... /> [code]
ld ly,8
.loop
ld sp,ix ;IX = beginning ... br /> exa
pop de
ld l,e ;H = MSB ... of font data
ld a,(hl)
ld l,d
xor ... /> and #F0
xor (hl)
ld (bc),a
inc c
RANDOMIZE USR, PRINT USR etcHello just wondering why is it called RANDOMIZE UsR what does randomising have to do with it ? When calling machine code routine from adress x you ty…
... /> pop bc ;BC=$3365
pop de ;DE=$0000
inc sp
inc sp
pop hl ;HL ...The state of source level debuggingI was just wondering if we can put on a table everything we collectively know about source level debugging for ZX Spectrum to get an overview of curr…
... /> (3) ld hl,0 ; to receive SP
(1) add hl,sp ; hl=sp
(1 ... buggy core.
(1) pop hl ; else called from ROM, restore ... buggy is present in printer buffer
[/code]
... :
- push all regs/pop all regs (if received command ...Graphics program in AssemblyHi so I think I'm getting the hang of this so I've done this program. It writes directly to the screen. I'm using ZX Spin. [code] LD HL,16384 LD B,…
Doesn't make sense wouldn't this give me the value of BC ?
[code]
org 33000
LD HL, 23452
PUSH HL
POP BC
RET
[/code]
If I assemble then PRINT USR 33000
shouldn't it print 23452 on screen ?how to fix instructions on screenI have a problem with my sequencer. I want the top half of the screen to stay fixed but allow the note values to print without pushing the instructio…
... to the part of the screen you want to use, like ... /> LD A, 2 ; this directs the printing to the upper screen
HL
LD A, 2
CALL $1601
POP HL
POP DE
POP BC ... a channel to the lower screen, you simply use a value ...The state of source level debuggingI was just wondering if we can put on a table everything we collectively know about source level debugging for ZX Spectrum to get an overview of curr…
... ) ld hl,7 ; to receive SP and add offset
(1) add hl,sp ; points ... to buggy core.
(1) pop hl ; else called from ROM, restore ... regs and return
(1) pop af
(1) ret
buffer
[/code]
[/quote]
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…
... of screen address
sub 8 ;subtract 8 from it
ld ... of screen address
sub 8 ;subtract 8 from it
ld ... /> ex (sp),hl
djnz msl_draw_loop ;rinse and repeat
pop hl ;pop screen_addr from ...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…
... /> ld a,h ;else, load A with high byte of screen address ...
sub 8 ;subtract 8 from it
ld ... /> ex (sp),hl
djnz msl_draw_loop ;rinse and repeat
pop hl ;pop screen_addr from ...z80 Helper?When you are programming with z80 do you get 'lost' you are in the middle of making a routine and you can't remember which registers are holding val…
... one.
A PUSH/POP pair takes 21 cycles and ... code can most often just pop as it needs the stored ... involves doing things like "pop af; pop bc; push bc; push af" to get ... stack (now in BC) or "ld hl,n; add hl,sp; ld a,(hl)" and so on ...Interupt service routinehas anyone set up a interupt service routing with pasmo? this one I tried resets the speccy EDIt- I placed the code after the END directive, I fi…
... /> ld hl,48640 ; 190*256
ld de,48641
ld bc,256
ld (hl),189 ... /> ld (23295),a ; Write A to the corners of the screen
pop af ; Restore AF
screen to show it's working ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... _ulzfa050
_ulzfa050ld:
ld a,(hl)
ld (de),a
;; move ... , follow char layout of screen
_ulzfa050:
ld a,d ; 4t ... hl ; 7t
push bc
pop ix
;...
ld a ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... /> org $c000
ld hl,screen ; 10t - start location of ... ld e,(hl) ; 7t
inc hl ; 6t
ld d,(hl) ; 7t - start screen ... hl ; 11t - store hl for later (sp=store pos)
ld ... pop hl ; 10t - bring back mem pos (sp=free)
inc hl ...Using the stack to blit bufferI was using a ldir to blit my back buffer to the screen RAM, and it was working pretty well if not rather slow. After reading about using the stack …
... ld sp,0
pop hl
pop de
pop bc
pop af
exx
pop hl ...
pop de
pop bc
cred_adr_2 ld sp ...The point of IX+1 IX+2 ?the numbers that you can add-on to IX and IY seem hardcoded, so I dont see the use of that feature? any examples of the use of IX and IY plus number…
...
ld hl,party
ld a,FCH_ADD_HP
ld bc,20
pop hl
pop af
jr loop ... number of terminal windows on screen with varying characteristics at little ...what is wrong with this loop?here is the loop: ld b,12 ld a,31 ld de,right_screen_array right_screen_array_label call charaddress ex de,hl ;de now contains screen address…
... /> pop bc
pop af
ex de,hl ;de now contains screen address hl contains ... array location
ld (hl),e
inc hl
ld (hl ... ),d
inc hl
ex de,hl ...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... plot a dot on the screen, you can skip the PLOT ... />
[code]
ld hl,$6400 ;100 (64 hex) into ... br /> push hl
exx
draw
ld bc,$18c ;1 ... 9402
exx
pop hl
exx
ret ...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... HL on stack
exx ; Switch to normal registers
ld bc ... /> pop hl ; Restore alternate HL from ... jp nz,ROM_PLOT ; screen, if not repeat
Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... HL on stack
exx ; Switch to normal registers
ld bc ... /> pop hl ; Restore alternate HL from ... jp nz,ROM_PLOT ; screen, if not repeat
Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... hl ; Store HL registers
push bc ; Store BC registers
ld ... pop bc ; Restore BC registers
pop hl ; Restore HL ... screen ...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... br />
PAINT_CHAR ld (hl),c ; Load ATTR byte ... />
pop bc
pop hl
add hl,de ; Add 32 ... Ts to paint the whole screen.
...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... />
Finally, reuse the screen-to-buffer loop, but reverse the source ...
pop hl
call WAIT_KEY
push hl
ld de ...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... Buffer (8 bytes)
; ------------------------------------------------------------------------------
MAIN ld hl,(ROW_COL)
ld ... pop hl ; Restore HL registers ...Thought this would be simple... Z80Hi Folks, Started to read "Beyond simple BASIC, Delving Deeper into your ZX Spectrum" by Dilwyn Jones. This is a great book and I came across the…
... /> ld hl,OLD_B1 ; Source address
ld bc,8 ... screen data
pop hl ; Restore display file address
ld ...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…
... />
;————————PREPARE SCREEN AND DISPLAY CONTROLS———————
ld a,71 ;WHITE ... de ;table row
pop bc ;restore counter
djnz 2 ... /> control_count ld bc,0 ;(SMC) count BC keys up (HL will be incremented BC times ...Loadsa bullets on screen (silkworm)Did games like silkworm just draw everything to the screen or did they have complicated optimisations? and the types of games where sprites can occu…
... /> [code]
ld sp, copy_table ;16-bit source, destination
ld bc, 3456 ; 27 ... *128
loop:
pop de
pop hl
ldi ... ldi ; 27 ldis
ld a, (hl)
ld ...
