-
When would you use LD A,R ?Can anyone tell me a practical use of LD A,R and LD R,A I am confused when you would need to use it? Cheers
... tell me a practical use of LD A,R and LD R,A I am confused ... />
Interface 1 uses LD A,R as a random number when two ... ZX80 and ZX81 use LD R,A to directly set the refresh ... -
AY programming and notes frequencyHello everybody, I'm Targhan from the french CPC group Arkos, perhaps you've heard of us. I'm currently working on a music tool and I'd like to k…
... happening "back-to-front"! i fixed it in my ... the player by adding "LD (DelyCnt),A" before the RET line ... in C_DELAY.
i ... folder - presumably it's a dump of the periods ... PT3?)
personally, i don't think the slight ... -
Speccy games programmingI've got a question. Where games written in pure machine code or was it a level higher with Assembly language being the choice? I always thought it…
... equivalent of a disassembler...[/QUOTE]
I like that ... OP:[/U] The way I see the difference (although ... pop af ;Instruction to A
ld (hl),a ;Restore it
... -
Speccy games programmingI've got a question. Where games written in pure machine code or was it a level higher with Assembly language being the choice? I always thought it…
... the OP:[/U] The way I see the difference (although ... is that in assembly language I can do:
... pop af ;Instruction to A
ld (hl),a ;Restore it
jp ... -
Sprites...What is fastest way for drawing masked sprites at any screen position without using preshifted data ? I want to use it for isometric view game... li…
... of doing that ?
I know about addressing mode (IX ... ),d
but I have 16bit table_base and 8bit ... bytes wide sprite data?
I have two bytes of sprite ... de
45 ld l,a
46 ld a,(hl) ; a = spr mask rotated ... -
AY programming and notes frequencyHello everybody, I'm Targhan from the french CPC group Arkos, perhaps you've heard of us. I'm currently working on a music tool and I'd like to k…
[QUOTE=aowen;401622]Also I presume the bugifx is supposed ... code?[/QUOTE]
yes, i guess it should be like ... /> ld a,(bc)
inc bc
ld (pt3_delay+1),a
[B]LD (DelyCnt),A ... it's working by playing a song that uses alternating tempos ... -
When would you use LD A,R ?Can anyone tell me a practical use of LD A,R and LD R,A I am confused when you would need to use it? Cheers
[QUOTE=BloodBaz;402226][B]LD A, R[/B] can be used ... /> [code]
XOR A
loop: LD R, A
JR loop
I hate to be picky but...
thats not[B] LD A ... -
Adjusting your code for screen refreshingOk, I'm aware that I should know it already after writing 5 Spectrum games in machine code but interrupts and screen refreshes were always my weaker …
... garantee for correctness!) I copy a note which I made long time ... A
LD (23672),A ;reset 'FRAMES' to 0
LD (23673),A
LD ... ]
Please note that I am not trying to compete ... with the professionals, I am just sharing my thoughts ... -
When would you use LD A,R ?Can anyone tell me a practical use of LD A,R and LD R,A I am confused when you would need to use it? Cheers
... I lack on a freshly powered up Speccy is a source of randomness. I ... need to generate a random number ... br />
However, I wonder if setting a chunk of RAM to ... , then doing a loop for a while with XOR A/LD R, A will also ... -
Spin Assembler DirectivesLeading on from [URL="http://www.worldofspectrum.org/forums/showpost.php?p=402514&postcount=65"]jp's recent post in Spin 0.7 Public Testing thread[/U…
... )'; I: 141),
(S: '.IF'; I: 170),
(S: 'A'; I: 120),
(S: 'A ... '#39; I: 128), (S: 'ADC'; I ... : 'L'#39; I: 135),
(S: 'LD'; I: 53), (S: 'LDD'; I: 54+($FFEDA8 ... -
Spin Assembler DirectivesLeading on from [URL="http://www.worldofspectrum.org/forums/showpost.php?p=402514&postcount=65"]jp's recent post in Spin 0.7 Public Testing thread[/U…
... )'; I: 141),
(S: '.IF'; I: 170),
(S: 'A'; I: 120),
(S: 'A ... '#39; I: 128), (S: 'ADC'; I ... : 'L'#39; I: 135),
(S: 'LD'; I: 53), (S: 'LDD'; I: 54+($FFEDA8 ... -
When would you use LD A,R ?Can anyone tell me a practical use of LD A,R and LD R,A I am confused when you would need to use it? Cheers
... ;402796]One thing I lack on a freshly powered up ... LD A,D
LD H,E
LD L,253
OR A ...
SBC A,D
LD E,A
SBC ... -
When would you use LD A,R ?Can anyone tell me a practical use of LD A,R and LD R,A I am confused when you would need to use it? Cheers
... I lack on a freshly powered up Speccy is a source of randomness. I ... need to generate a random ... keep in ROM
ld h,a
ld a,(hl) ; random ROM address ... ; some more randomness
ld (23672),hl ; store random number ... -
AY programming and notes frequencyHello everybody, I'm Targhan from the french CPC group Arkos, perhaps you've heard of us. I'm currently working on a music tool and I'd like to k…
... a revised version of the code. I've managed to trim it a ... select the tone table, but I suspect that's always been ... /> ld a,03eh
ld e,a
add a,a
sbc a,a
ld d,a
ld ... -
Machine Code Microdrive File LoaderI've been experimenting with transferring games to run from microdrive. Typically I like to see a loading screen while things are happening, and I li…
... at 216 bytes!
I can provide an updated demonstration ... cartridge, but I'm still using a denienced game...
;
ld a,$ff ;
ld (err_nr),a ; force a clean error code ... -
What Z80 development tools do you use? What books?Hi. I've been meaning to do it for over 25 years, but.. better late than never :) I'm starting to learn machine code and am trying to get a developme…
... . .[/QUOTE]
I must admit I second that. I've tried out ... ld a,0
loop inc a
ld b,0 ;
ld c,a ... br /> My second program, [I]Multicolour Border[/I], is interesting...
I] :-o I doubt my Pentium ... -
What Z80 development tools do you use? What books?Hi. I've been meaning to do it for over 25 years, but.. better late than never :) I'm starting to learn machine code and am trying to get a developme…
... />
[/CODE]
I've never used the ROM ...
My second program, [I]Multicolour Border[/I], is interesting...
; ld a,h
; and a
; jr nz,loop2
; ld a,l ... br /> [/CODE][/QUOTE]
I suppose at the moment machine ... -
What Z80 development tools do you use? What books?Hi. I've been meaning to do it for over 25 years, but.. better late than never :) I'm starting to learn machine code and am trying to get a developme…
...
xor a
ld (5C3Ch),a ;open screen for printing ... />
[/CODE]
I've never used the ROM ... one! ;)
I suppose at the moment machine ... flippy minimalist Z80.. know what I mean? Especially when you're ... -
What Z80 development tools do you use? What books?Hi. I've been meaning to do it for over 25 years, but.. better late than never :) I'm starting to learn machine code and am trying to get a developme…
... TIMES
;
xor a
ld (5C3Ch),a
;
call ... loop2 ld a,8
;
loop dec a ;[U]THIS I PRESUME CHANGES ... /> ;
dec hl
ld a,h
or l
i]why[/i] XOR A is the same as LD A,0 etc ... -
lol cat lives ?Had this pic for a while, just had a quick text change to something more speccy appropriate. [IMG]http://img.photobucket.com/albums/v294/yellow_spid…
... ;411782]The original one I had said "lives-1"
I've disassembled use that register ... of games I hacked (about 120-150 I think) have DEC A :)
DEC A
JP Z, REST_IN_PEACE
ld (lives),a :) -
Anybody got a hack for PAW'd games?Has anybody got a hack to browse the text in PAW'd games?
... URL=http://img23.imageshack.us/i/blink2a.gif/][IMG]http://img23 ... code]
org $8000
ld a,2
call $1601
i/blink.gif/][IMG]http://img641 ... URL=http://img25.imageshack.us/i/reflection.gif/][IMG]http://img25 ... -
Thunderbirds (by Firebird) on 128k SpecciesHi all. Anyone got Thunderbirds working on a 128k machine (+2) ? On WOS there is an original TZX and a Z80 snapshot in 48k mode, but you cannot run …
... were responsible for z802tzx if i'm correct, and that page ... of trd recracks (which i painstakingly did all of for ... +3 working...) I got 2 plus3e's so ... i crack everything for that - ... 23296 just doing IN A,254 LD (HL),A DEC HL LOOP so ... -
Machine Code Routine of the weekHow about a thread that has a routine each week that is in [B]assembly language[/B] and is also described in great detail what the hell is going on …
... /> ld hl,keys
ld de,keys+5
ld (de),a ; ... ld a,(de) ; now fetch address of routine
ld l,a
ld ... within the same highbyte
i.e.
Keys = # ... -
Mass storage - why backup battery?I wasn't sure to post this under "hardware" or "development", but here goes: There are these mass storage devices for ZX Spectrum, and on many desig…
... Spectrum peripherals.
Personally, I'm not so keen on ... ones over ethernet. I don't even own a flash programmer device ... - you can't just LD (HL), A to set a byte, you have ... obvious route for the Spectranet. I'm more than happy with ... -
Double Dragon 128k - The graphicsAs you are all probably aware, I tried gathering a team of people together a few years back to make a totally re-programmed version of Double Dragon …
... you using there Swainy?!?!?), I thought Id recompile them again ... to, incidently)...
I didn't change much: Loop2 ... br /> viewer_loop7
ld (viewport_y), a
xor a ;EDITED: Added (was ... br />
Right... now I really must go to bed!!!! -
Character scrollingOk, first I'd like to say that I'm not looking for a complete routine (but that might help) because I am hoping to write it myself and learn a bit mo…
... , d ; b = roll amount
ld a, c
.doroll
rrca ... ; roll amount times
ld (hl), a ; store result
inc hl ... ; next roll amount
ld a, 8
cp a, d ; d = 8 ... than 1.75K).
I put the oneoffinit code to ... -
Help fix this keyboard read program?This code runs in an interrupt routine with DI. What would be the simplest way of making it so it doesn't auto repeat a keypress? [code]keys: ld a…
I've amended your routine to save a copy of the state ... on some spectrum models
ld (hl), a ; Save keystate this time ... ;
bit 2, a ; Test for 'i' key
jr z ... , movekeyi ;
bit 3, a ; ...
