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Using INPUT without clearing last two lines of screen?I'm trying to print to the 22nd row of the screen using the ol' print #0 trick. Unfortunately, I require user INPUT which seems to wipe out the botto…
... continues.
Don't forget to save B somewhere ... , b
or c
jr nz, .loop
[/code]
... Since DEC BC doesn't set the Z flag when ... .
Again, don't forget to save BC if ... that register pair. You don't have to use BC, ... -
Jetpac questionHi all, I just bought a copy of Jetpac off of Ebay and I'm having problems. To start, I'm trying to play it on an issue 2 Speccy with Interface 1, 2 …
... ...
I probably won't be able to work on ... ,(HL)
CP 170
JR NZ,MEASURE_FAIL ; This address failed to ... ,H
CP E
JR NZ,InversionFill1 ;Wrapped around to ROM ... ,H
CP E
JR NZ,InversionTest1 ;Wrapped around to ROM ... -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... : cpi ; a-(HL)
jr z, found
[COLOR=DimGray ... bc==0 here[/COLOR]
jr nz, search
[B]ret ... be reached. I can't seem to find an ... should really use JR search. It doesn't save any ... -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... should really use JR search. It doesn't save any bytes ... : cpi ; a-(HL)
jr z, found
ld a ... , 0 ; restore A
jr nz, search
ret ; not ... code]I suppose I don't need [I]ld a, ... -
Thinking in Assembly (first efforts)The following is one small routine to educate myself on a few concepts (jumps, flow control, routines, CPI): [code]searchmem xor a …
... ; flag decoy. BC==0
jr nz, search
ret ; not found ... [/code]I suppose I don't need [I]ld a, b ... -
MultichromeIt turns out that multichrome, and other screen modes, are emulated in Fuse and Eightyone via ZX Spectrum SE emulation (which is similar to the TC214…
... , so for now it doesn't work on regular ZX128 which ...
dec c
jr nz,pg
ld a,(pg ... -
Problem Wrapping SpritesHi, I am having an issue wrapping my sprites around the screen, Basically, I have a back buffer which is 24 chars (192 Pixels) by 28 chars (224 P…
... check, is it negative?
JR NZ,MOVEX_NEG ;if so move to ... to retain the relocatable [B]JR[/B] instruction. But as ... 2-byte instruction you wouldn't save anything over your ... BIT 7,A[/B] doesn't destroy [B]A[/B]. ... [B]A[/B] isn't important.
;) -
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 …
... key is pressed which doesn't use the ROM or system ... /> cpl
and %00011111
jr nz, _WAITFORNOKEYS
ret
[/CODE] -
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 …
... key is pressed which doesn't use the ROM or system ... /> cpl
and %00011111
jr nz, _WAITFORNOKEYS
ret
[/CODE ... -
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 …
... the column of keys isn't pressed, so this inverts that ... result, the other 3 aren't important as only five keys ... pressed, so loop around.
jr nz, _WAITFORNOKEYS
; No keys pressed ... -
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 …
... key is pressed which doesn't use the ROM or system ... /> cpl
and %00011111
jr nz, _WAITFORNOKEYS
ret
[/CODE ... ][/QUOTE]
Doesn't rely on Interrupts being Enabled ... -
Maze Mania - How did they do it?Hi, I was looking at the game "Maze Mania" by Hewson Consultants, written in 1989. The game can be downloaded from here [URL]http://www.worldofspec…
... ,B
OR C
JR NZ,loop
LD A ... ; Move to next row
JR NZ,line_loop ; repeat until all done ... /> This takes about 79,000 T-Cycles, so I reckon with ... -
Fastest Block Drawing Code?Following on from my scrolling thread [URL="http://www.worldofspectrum.org/forums/showthread.php?p=351304#post351304"](http://www.worldofspectrum.org…
... in PASMO and takes 2772 T-Cycles to draw one ...
and 7
jr nz,npl_ok
ld a,h ... a
and 224
jr nz,npl_ok
ld a,h ... -
Fastest Block Drawing Code?Following on from my scrolling thread [URL="http://www.worldofspectrum.org/forums/showthread.php?p=351304#post351304"](http://www.worldofspectrum.org…
... 351348]So, don't store your screen ... blocks that don't cross screen block ... and 7
jr nz,npl_ok
ld ... and 224
jr nz,npl_ok
ld ... -
Fastest Block Drawing Code?Following on from my scrolling thread [URL="http://www.worldofspectrum.org/forums/showthread.php?p=351304#post351304"](http://www.worldofspectrum.org…
you can save a 2T replacing JR NZ, ... by JP NZ, ... but it will not save you...
accord my computing you are at 16T/byte now
somewhere in this forum gasman's multicolor routine is buried. multicolor -
Rainbow Generator for 48K Spectrum using PUSHThis is what I came up with from [B]gasman[/B]'s suggestions. It's stable in ZXSpin and ZX32 simulating a 48K Speccy. Anyone like to try it on the …
... trapped so attributes don't get printed outside the ... />
; error trapping doesn't try to print attributes
dec c ; next counter
jr nz, loop ; finished?
ret ; ... 04t => 022t
jp nz,interrupt_delay_loop ; 10t => 032t per ... -
Reading from the 128 Serial PortDon't shout at me if this is a silly question. I have Googled extensively, and searched the forums, but I can't find anything discussing what seems t…
115200 Baud is indeed possible for transferring files from PC to Spectrum.
I used a test file holding 6912 times CHR$ 51, and "Splitcom" found at:
[url]www.propix.hu/share/SplitCom/SplitCom.html[/url]
Baud rate 115200, 8 data bits, no ... -
Interface One - New FunctionalityAs you may (or may not) be aware the Interface One is a pretty powerful piece of kit. One of it's greatest features is being able to easily extended …
... 2 num.expr.
JR NZ,fe1 ;JP if runtime< ... HL ;Drop returnadress
JR F_piend ;Exit
fe1 ... /> LD B,A
JR F_pistack ;Exit
t tell how IF1 catches ... -
Interface One - New FunctionalityAs you may (or may not) be aware the Interface One is a pretty powerful piece of kit. One of it's greatest features is being able to easily extended …
... and, for me, doesn't quite scratch the surface. Don ... 't get me wrong though ... s more scope... wouldn't it be useful to ... 04a8 fe 40 $07ts
jr nz, l_048b ; 04aa 20 df $07 ... ; 04cf eb $04ts
jr nz, l_04d5 ; 04d0 20 03 $07 ... -
Tinkering with Quique Llar?a's Midi2Ay tool...Im tinkering with Quique Llar?a's Midi2Ay tool, found at: [url]ftp://ftp.worldofspectrum.org/pub/sinclair/tools/pc/midi2ay-0.1.zip[/url] Im not a v…
... im 2
ei
;;;;; jr $
ret
t done here.
< ... /> or a
jr nz,finrsi
inc hl< ... reti so that peripherals don't become confused
< ... basic system ISR wouldn't run (this includes ... -
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…
... +CHP_NtSkCn
dec (hl)
jr nz,pl1b
AdInPtA:
ld ... CHP_NtSkCn
dec (hl)
jr nz,pl1c
ld ix,ChanB ... rout_a0
dec (hl)
jr nz,rout
env_del
ld ... ;delete #90 if you don't need default sample
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
... bit 7 (that doesn't change with the auto- ... br /> or a
jr nz,Beeper ; if so then ... br /> add a,a
jr nz,PlayFX
ld (FXNumber),a ... br /> djnz Beep0
jr Beep1 ; this is right!< ...More colours II (Was: Most popular new features?)The suggested 4xCLUT multi-colour solution never took off.
... slide show code which isn't trying to do things quickly ... we nearly there yet?
jr nz, setreg ; repeat until all 64 ...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 …
... /> OR L ;4
JP NZ,LOOP ;10
LD ... itself takes 45 T-states each round, this leaves 1719 T-states
... to 224 Z80's T-states. So some 15600 T-states pass before data ... executed first, taking some 1800 T-states away. Leaving around 13500 for ...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…
... +CHP_NtSkCn
dec (hl)
jr nz,pl1b
AdInPtA:
ld ... CHP_NtSkCn
dec (hl)
jr nz,pl1c
ld ix,ChanB ... rout_a0
dec (hl)
jr nz,rout
env_del
ld ... ;delete #90 if you don't need default sample
More colours II (Was: Most popular new features?)The suggested 4xCLUT multi-colour solution never took off.
... 256 colours. Most pictures aren't going to use all 256 ... .[/QUOTE]
I don't know where you get 48 ... on every line. I don't know if it's possible ... not, but if it isn't then that's too bad ... we nearly there yet?
jr nz, setreg ; repeat until all 64 ...
