-
this code wont give me a random starfieldim using a peice of code that ive copied from a book, ignore most of it as it is redundant. for some reason i get a strange random starfield instead …
... ; number of stars.
loop: push bc
Again: call GetRnd ... ; plot
pop bc
dec bc
ld a,b ... -
this code wont give me a random starfieldim using a peice of code that ive copied from a book, ignore most of it as it is redundant. for some reason i get a strange random starfield instead …
... ; number of stars.
loop: push bc
Again: call GetRnd ... ; plot
pop bc
dec bc
ld a,b ... -
How to write a simple BASIC* horizontal scrolling game (Tutorial) [b]How to write a simple BASIC* horizontal scrolling game[/b] In this tutorial, we will be talking about how to write a simple BASIC* horizont…
... 175
loop: PUSH BC ; 60009 197
LD BC, 31 ; 60010 1 ... DE ; 60017 19
POP BC ; 60018 193
DJNZ loop ... -
How to write a simple BASIC* horizontal scrolling game (Tutorial) [b]How to write a simple BASIC* horizontal scrolling game[/b] In this tutorial, we will be talking about how to write a simple BASIC* horizont…
... to XOR A rather than PUSH BC. What is going on?
How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... cell anywhere on the screen (or to a screen buffer).
... that straddle the weird screen thirds boundary you have ...
I used a back screen buffer to draw to which started ...
sprite8x8a:
; calculate screen coordinate of top of cell ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
...
; this points at the screen RAM at the moment. You ... to an off screen buffer and copy that to screen if you want ... used to be (middle of screen) which needs to be inside ... EQU 0 it allows full screen movement and does not draw ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
...
ld d, 0
push hl
ld hl, de ... /> ld (ix+1), h
push bc
call sprite8x8a
pop ... bc
pop hl
inc ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
...
ld d, 0
push hl
ld hl, de ... /> ld (ix+1), h
push bc
call sprite8x8a
pop ... bc
pop hl
inc ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... trash B register unless you PUSH BC before you trash it and ... POP BC before DJNZ
; or you ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
...
ld d, 0
push hl
ld hl, de ... /> ld (ix+1), h
push bc
call sprite8x8a
pop ... bc
pop hl
inc ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... ld b, 11
push bc ; push loop counter
ld b ... /> ld c, 1
push bc ; push coords
.botrowloop
... ld a, (ix+1)
push bc
call setattrib2x1
... inc e
; push loop counter
push bc
ld b, ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... ; do this 2 times
push bc
push hl
; set collision ... a, (ix+7)
push hl
push bc
call setattrib2x1
ld l, (hl)
push hl
push bc
ld de, gfx16x16_player ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... br />
If you push register pairs you need to ... this:
push hl
push bc
; trash hl and ... bc
pop hl
pop bc< ...
push hl
push bc
; trash hl and bc
pop bc
How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
[code]cls push hl
push bc
di ;disable interrupt
... repeat 256 times
pop bc
pop hl
ld ...How to disable the "scroll?" message?Hello. I'm a beginner Z80 assembly programmer and I decided to make a ZX Spectrum game to practice my skills and gain some more experience. I curr…
... the register, you need to push it to the stack and ... need to do both a PUSH BC and PUSH HL (since they are ... . It's better to only push 1 register pair not 2 ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... to an off screen buffer and copy that to screen if you want ...
SCRBUF_BASEADDR is just the screen address, might want to change ... not draw directly to the screen.
WINDOW_ stuff is ... the attributes (straight after the screen)
STRIPES set to 1 ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
...
.nextline
push bc ; push loop count
ld d ... by 2
push hl ; push pointer to next line ... ld l, a
push hl ; pointer to line drawing ... .nextloop
.deallocline
push bc
call line_data_dealloc
pop ...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…
... /> .heapify_words_body
; push root & count
push bc
ld a ... ; A = largest
pop bc
cp c
ret ... ; swap largest with root
push hl
ld e, a ... add hl, de
push af
push hl
or a ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... ; step = step / 2
push hl ; remember old value of ... a
.loop
push bc
.doitagainx
call ... /> ld c, a
push bc
.doitagainy
call ... jr c, .doitagainx
pop bc
djnz .loop
; ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
...
.nextline
push bc ; push loop count
ld d ... by 2
push hl ; push pointer to next line ... ld l, a
push hl ; pointer to line drawing ... .nextloop
.deallocline
push bc
call line_data_dealloc
pop ...Robospec (new project, hopefully useful as a tutorial as well)Starting a new project after my graphics investigations. * It's gonna be a Robotron clone since that's not too ambitious (although I'd like to hav…
... /> .heapify_words_body
; push root & count
push bc
ld a ... add hl, de
push af
push hl
or a ... srl b
.reheapify
push bc
ld a, b
swap_word
push bc
ld c, 0
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…
... to use a Double Buffer (DB) or 'Back Screen' to draw all ... lot onto the main display screen. This allows me to more ... hl, 25000 ;Start of DB Screen
ld de, 16384 ;Start ...
loop1:
ld bc,32 ;BC is counter for block copy ...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…
... fastest way to update the screen. I know that ldir/lddr ... , but not sure about the push vs ld (hl),a.
LD BC,len/2
LD D ...
LOOP
PUSH DE
DEC BC
LD A,B ...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…
... :
di
push iy
; Draw ... bc,6143
ldir
; Copy from store to the screen ... 32
lp1:
push hl
...
