-
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... horizontal
AND 240
JR NZ,up
down:
; ... 5)
CP RECTBOTTOM
JR NZ,up2
LD ... /> CP RECTRIGHT+1
JR NZ,ps2
LD A,RECTLEFT ... -
IM2 Machine Code Sprites Example Code Using Char Based SystemFurther to my earlier post, here are sprites running using char method with IM2 driving it Note, for 48k spectrum using TASM [code] ; ***********…
... horizontal
AND 240
JR NZ,up
down:
; ... 5)
CP RECTBOTTOM
JR NZ,up2
LD ... /> CP RECTLEFT-1
JR NZ,bs2
LD C,RECTRIGHT ... -
I would like to write emulatorHi guys, I'm new to this forum but I realise that you must get loads of posts from people asking "how do I write an emulator" so I'll try and be spe…
... opcode takes a number of T-States to complete. Keep a counter ... -
I would like to write emulatorHi guys, I'm new to this forum but I realise that you must get loads of posts from people asking "how do I write an emulator" so I'll try and be spe…
... opcode takes a number of T-States to complete. Keep a counter ... explaining to me what T and M states are? I think I ... -
Smooth Color Masked Sprites using fast page flip on 48kHere is a quick demo of using char based sprites using the Page flip method: a) Background is copied to buffer b) Sprites drawn on buffer c) Buffer …
... LD (COUNT),A
JP NZ,go2
JP NZ,go
CP 8
JR NZ,ok1
... /> CP 16
JR NZ,ok2
LD A ... -
Smooth Color Masked Sprites using fast page flip on 48kHere is a quick demo of using char based sprites using the Page flip method: a) Background is copied to buffer b) Sprites drawn on buffer c) Buffer …
... (COUNT),A
JP NZ,go
... ),A
JP NZ,goa
restoreb ... A
CP 8
JR NZ,ok1
LD ... br /> CP 16
JR NZ,ok2
LD A,0 ... -
Smooth Color Masked Sprites using fast page flip on 48kHere is a quick demo of using char based sprites using the Page flip method: a) Background is copied to buffer b) Sprites drawn on buffer c) Buffer …
... ,B
CP 255
JR NZ,prelp
JP NZ,go
...
CP 8
JR NZ,ok1
LD ... /> CP 16
JR NZ,ok2
LD A, ... -
On 48k, can I copy 4k before next screen updateFollowing on from my thread at [url="http://www.worldofspectrum.org/forums/viewtopic.php?topic=6423&forum=11"]http://www.worldofspectrum.org/forums/v…
... bytes gets copied in 51200 T states which is < the 68xxx ... to 20% longer or ~61440 T but this is something you ... Spectaculator reports the number of T states since the last interrupt -- set ... interrupt. There are about 14000 T states spent by the ula drawing ... -
Wanted: Code to wait until Border has been drawnWhen my IM2 interrupt fires, I want to wait until the ULA is past the first line of display before drawing. I know I need to wait about 14300T after…
... this. I prefer the counting T states method, but make use of ... lot of things in 14000 T states. The jitter between machines doesn ... even if jitter is 200 T states. If doing multicolour effects, you ... machines in the number of T states spent in the top border ... -
TZX and the ZX81Evenin All. EightyOne is now is a state where I can support a more descriptive tape format. I know how some people have been calling for tzx suppor…
... Length of a Pulse in T-States
06 2 Length of ... the last byte (I don't think anything ever put out ... data it encodes isn't. The ZX80 doesn't put out any ... -
Can Anyone explain sprites in Jet Pac/Atic Atac etcJet Pac was 16k, and yet the sprites were impressively fast. I notice they had a slight flicker at times, but were notmally pretty flicker free. W…
... /> and 31
jr nz, 50 ;check if sprite wraps ... and 31 ;goes around
jr nz, 6D
ld a, ...
and a
jr nz, 5C
exx
... ld a, l
ret nz
sub 32
... -
RZX for Sabre WulfI was just about to send an RZX for Sabre Wulf to the RZX Archive when I noticed they don't accept Ultimate's (and other companies' who haven't given…
... when I noticed they don't accept Ultimate's (and ... other companies' who haven't given permission) files.
[/ ... between those companies which haven't given permission (most of them ... with some additional stuff like T-states.
[/quote]
... -
Cobra - scrollingHi everyone, I have been studying some of the code in Ocean' Cobra game using a debugger, in the hope of improving my own scrolling routines. In cas…
You mean it is so fast that they actually had to slow it down by 70000 T-states???!!! yikes! -
Cobra - scrollingHi everyone, I have been studying some of the code in Ocean' Cobra game using a debugger, in the hope of improving my own scrolling routines. In cas…
Judging by the quoted number of T States it's probably a routine to wait for screen sync. -
How can I see how long it took for IM2 to runHow can i see how many cycles it took for my interrupt routine to run, is there some way with Spectaculator debugger etc to see how long it has taken…
Assuming the debugger has breakpoints and T-States set a breakpoint at the start and end of the IM2 vector - the difference in T-States will give you the number of cycles it took to complete. -
Sprites flickeringI am trying to write a Spectrum game in machine code. I am still a beginner in programming, however I did much progress recently, i believe. Now I am…
... for the correct number of t-states, or by performing another task ... -
Reading the keyboardDoes anyone have a code sample to read the keyboard in machine code ?
... (HL)
INC HL
JR NZ,NOPRESS
LD E,(HL ... -
Help required to calculate screen addressesDoes anyone have some code that calculates the screen address one pixel below the given address ? Is it best to use a lookup table ? Any examples of …
... ,d
and 7
jr nz,nextline
ld a,e ...
ld e,a
jr c,nextline
ld a ... -
Key Redefine RoutineAnyone written a nice key redefine code snippet?
...
CP %11111
JR NZ,KEY_PR
SCF
RR ... B
JR C,KEY_L
JR REDEF
KEY_PR ... br /> INC B
JR COU_L
COU_E LD ... -
Z80 register decoding document error?Hi, I've been working on a disassembler using the following document written by Cristian Dinu (aka GOC?). [url="http://www.z80.info/decoding.htm…
... nothing. If the difference isn't obvious, think about interrupts.
t affect anything). After the optional ... instruction that takes 4 more t-states.
Actually, even a ... 'x-state NOP' notation isn't 100% accurate, seeing as how ... -
Spectrum programmingI have a Spectrum+ at home. I tried to write some programs in BASIC (IIRC i wrote a breakout clone in which you had to hit those spider-like characte…
... bits (5 keys/row)
JR NZ,START
The beeper ... -
new release of winTZXHi all I released winTZX 0.4drc1 (04/02/2005) + Added CSW file support + Added block selection (replay and save) + Added reverse output + Added direc…
... with it.
The T states for a pilot pulse is ... -
Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... the code again I can't actually see any reason for ... /POP DE and save 21 T States.
[ This Message was ... -
Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... L
saving another 4 T-states per run.
The ... 16 * 8 * 4 - 8 * 4 T States
Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... L
saving another 4 T-states per run.
The ... 16 * 8 * 4 - 8 * 4 T States
[/quote]
I haven't tested the code, but HL ...Help needed to speed up functionCan anyone help me to re-factor this code snippet. The "MAP" section holds information about which tiles go where on the screen (handled by another f…
... save a significant number of T-States per cycle (given that indexing ...The incredible shrinking screendumpIn this topic I stated that I would be impressed if the screendump could be smaller than 37 bytes. [url="http://www.worldofspectrum.org/forums/viewt…
... if I jump away on NZ and handle the RET otherwise ... reads as NOP and RET NZ
I can ... b
nop
ret nz
defb "K",27
call #22b0
jr nbyte
[/code]
nop
ret nz
defb "K",27
Anyone help re-factoring a tile functionI had some excellent feedback for re-factoring my function that displays the colour for my screen tiles. Can anyone offer some help to improve the fu…
SET 4,B = 8 T-states
LD B,16 = 7 T-states
See for timing
[url="http://www.z80.info/z80flag.htm"]http://www.z80.info/z80flag.htm[/url]Anyone help re-factoring a tile functionI had some excellent feedback for re-factoring my function that displays the colour for my screen tiles. Can anyone offer some help to improve the fu…
Thanks for that, I just spoted that one my self after searching the net for Z80 T-states.Interrupt timingsHow long does the ULA hold /INT low for on interrupt on each of the Spectrum models?
I've got a TS2068, and would be interested in getting this number worked out for that machine, though looking at the source it seems I need to know the number of t-states before the first non-border cell first.
TBC
