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HALT: Why always 4ts?Instruction breakdown of halt is like that: PC 4ts. That means it fetches instruction byte from ram which tooks 4 ts and then does nothing and read…
Instruction breakdown of halt is like that:
< ... tooks 4 ts and then does nothing and reads the ... .
if halt is already read by cpu ... the ram again and again to execute the HALT, why it ... if cpu executed HALT at cycle 5, and if interrupt triggered ... -
TV Pal, odd and even framesI have been researching, but haven't found any real interesting information on this subject, so far. What I mean is, since TV PAL signal is interl…
... so there are odd and even frames, which means ... since they just use HALT to sync on the Spectrum ... processing all lines (odd and even) on every frame ... weird idea to try and spark the collective imagination ... NTSC outputs (in USA, and maybe some other countries) , ... -
Text scroller and custom fontYesterday I was testing this text scroll routine taken from Jonathan Cauldwell's Intro Maker (labels have been inserted to allow partial code relocab…
... the ROM printing routines and copy them after the ... JR NZ, L_35381
L_35387: HALT
CALL 00654
... /> LD B,032
AND A
L_35425: RL ... : LD A,(DE)
AND C
JR Z,L_35464 ... LD A,(HL)
AND A
JR NZ, ... -
"Decoding z80 Opcodes" (http://www.z80.info/decoding.htm#intro) - Incorrect HALT Opcode?Apologies if this is a dupe but I searched within the forums and couldn't find anything. I've been working on a z80 emulator (for academic and rec…
... I searched within the forums and couldn't find anything.< ... emulator (for academic and recreational purposes) and have been using http ... seems to incorrectly specify a HALT opcode as 0x7[i] ... 5-3 should be 6, and 2-0 should be 7 ... if both digits 5-3 and 2-0 are 6. ... -
Double Buffering Artefacts on Real HardwareI have a project that I've played around with for a while and always tested using emulators, either ZX Spin or Spectaculator. It is a 128k game th…
... around with for a while and always tested using emulators, ... shadow screen for double buffering and when emulated it works perfectly ... buffering code is simply an IM2 interrupt that checks to see ... switch the screen after a HALT instruction.
Of ... -
No-tearing (“vsync”) Full Screen FadeSeeing as most screen fades exhibit visible tearing, I wrote my own routine which does away with that problem. Simple, effective, short, and fully re…
... problem. Simple, effective, short, and fully relocatable. Compatible with all ... of attr area
halt ;wait for beginning of frame ... is minimum for a custom IM2 routine
1$ dec ... ;reload A with attr
and $38 ;isolate PAPER
jr ... -
How to avoid flicking? IM2 help.Hi, I have started on a quest to make a demo for ZX Spectrum. However the display is flickering and I guess it is something about updating at…
... /> However the display is flickering and I guess it is something ... /> I have read something about IM2 without understanding it in details ... .dk/d/demo1.tap
And here is the code I ... -
ZEsarUX 8.1 stableHi! I've uploaded a new ZEsarUX 8.1 stable version. Go to the github released webpage to download it: https://github.com/chernandezba/zesaru…
... Wizard to automatically download and configure TBBlue official SD ... -added copper opcodes NOOP, HALT
-increased tbblue.mmc ... show interrupt routine pointer on im2 mode
Some other minor bugfixes and improvements
IM2 on a 128k SpectrumHello: I have found another article on IM2 found in Personal Computer News, Issue 90. In the article "Face up to the Time", I typed up the code (…
... have found another article on IM2 found in Personal Computer News ... #bec1.
The code and compiling files can be found ... . On a Sinclair 128k/+2 and Pentagon, I see text mixed ... using this to learn about IM2 on the 128k.
Which Emulator has a menu option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT?Which Emulator has a menu option / debugger option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT? I tried SpecEmu and Fuse, b…
Which Emulator has a menu option / debugger option to enable Interrupts (EI) if emulated Speccy hangs after DI / HALT?
I tried SpecEmu and Fuse, but I can not find a option for doing this in their debugger.VSYNC FunctionI have written a VSYNC function, so that I can clear the screen before redraw without flicker on the screen, I do this by peeking at the address 2367…
... and the entire program was in assembly? Would HALT ... 38 reads the keyboard and updates the frames system ... put the z80 in im2 mode and write an interrupt ... the instruction following a halt will be executed around ... thread (prior to the halt) was reading the frames ...Game loop design?Having some thoughts on how to design the game loop and could do with some hints and tips from folks who have done it before! It's all about how to …
... approach which is very easy and efficient to code. You can ... be much faster and hence execute comfortably in the IM2 sync. The ... that keyboard input is taken and objects are updated to new ... program
jump to HALT instruction
reenter IM2 vector
etc ...Collision DetectionHi everyone, This is my first post on WOS. Like most people here I owned a Spectrum when a teenager. At that time I was quite heavily into programmin…
... /> Map the sprite (mask and graphics respectively) to the offscreen ... /> Wait for the IM2 interrupt (using the HALT command)
Paint ... of the stored background and the offscreen drawing area ... the sprite moves around, and with new background stripes being ...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 (OKTOFLIP),A
HALT
JP MAIN ... =FE
IM 2 ; SELECT IM2
EI
... DE) ; Get Mask
AND (HL) ; And With HL
LD (HL ...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 (OKTOFLIP),A
HALT
... =FE
IM 2 ; SELECT IM2
EI
... DE) ; Get Mask
AND (HL) ; And With HL
LD (HL ...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 …
... br />
halt
LD A ... /> IM 2 ; SELECT IM2
EI
... Get Mask
AND (HL) ; And With HL
... ; 0FD00 - 0FDFCH RESERVERD FOR IM2 INTERRUPTS
ORG ...Pocket Clive - 2 QuestionsHello, I've just started using Pocket Clive on my iPaq pocket PC, excellent emulator BTW. 1. I have just wrote a small BASIC program to randomly pi…
... The game is running in IM2, (using the trick of having ... effect is greatly reduced, and the game becomes playable under ... further, by possibly relocating the 'halt' instruction.
However, it ... a perfect patch since the 'halt fix' method undoubtedly uses ...How can I tell if 128k in codeIs there an easy way in code to check if the Spectrum has 128k, rather than 48k so I can display a message "Must have 128k" etc
... a couple quick tests and tells you which machine ... techniques to do this, and which you would use ... this, set up an IM2 interrupt which does, something like ... [code] ld bc, 0
halt
ld a, 255
and test the byte. The ...Adding AY music to your plogramI'd like to add some nice tune to my program written in machine code. I am not new to assembler programming but with music programming I have no expe…
... , but all registers are saved and some ROM code involved with ... to set up your own im2 interrupt routine that replaces the ... totally useless but the custom IM2 one you write won't ... using an im2 interrupt routine, but is instead relying on HALT to ...Project: M.u.l.e.Wokani came up with a great idea about trying an open-development approach for spectrum games, and I thought why not try with a game I have under dev…
... exactly to put the halt statement and how to get this ... /doku.php/library:interrupts"]im2 library[/URL] description can ... ()
{
// initialize im2 mode
#asm
im2 is enabled and scroll_isr() is running in ...Dangerous Z80 Assembly CommandHave been reading Toni Bakers' "Mastering MC On Ya Speccy" book and came across the list of Z80 commands in the dictionary section. Page 102 "[b]IM…
... in the foreground, using the HALT instruction, like this month's ... BASIC after setting up the IM2 interrupt handler with the chip ... some wild address, and the screen typically corrupts, and the spectrum resets ... USR command on the screen and even the program STOP ...Announce: BASin r14b availableHere's the fix mentioned earlier for those of you that either are too lazy to update your OS (XP SP2 has been out aaaaages, Arjun!) or even junk that…
... tape it too crashed, and it too used IM2. I therefore loaded ... game (highly unlikely to use IM2). Arcadia worked fine. However, when ... program alters HL', IY and uses IM2 which isn't exactly BASIC ... with BASin - such as DI + HALT ?
One other thing ...How do you make AY sound?Are there tools? Or is it all done in assembler? Any tutorials around for people who like things explained in simple terms? Ta!
... tape with the music player and data embedded in it.
and call the player routine once ... the required machine code (using HALT) that you could you use ... probably want to use an IM2 interrupt routine eventually so that ...In-game music takes CPU time?If a 128k wants to have music played in-game using the AY sound chip, does that consume a lot of CPU time? What I am after is if the reason why man…
... attach to Interrupts (IM2). Many games use it, and you only have ... of my games using a HALT at the end of each ... in IM2 which does an immediate RET(I) instruction and then get ... speed is controlled by a HALT instruction is academic.Atic Atac speed.Dear all, Excuse the noob question, but does anyone know how fast Atic Atac runs at? What I mean is, frames per second, or the amount of pixels the…
... loads of games and you are better using Halt and interrupty things![/QUOTE ... thanks for the tip, superficially HALT/interrupts does seem easier anyway ... />
Even though I used HALT in the game I mentioned ... already to set up an IM2 mode routine - maybe I ...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…
... lines) containing the source address and the destination screen address. ... the pseudo code here (After halt) based on what I ... Mania
[code]
HALT ; Wait for Top Of Scanline ... , in reality would set up IM2 or something
DI ; ...The Goldfinch updates thread([url=http://www.worldofspectrum.org/forums/showthread.php?t=25034]original announcement thread here[/url] - I figured it was worth starting a new to…
... distinction between Gasware (the firmware) and Goldfinch (the overall project) - ... the full available memory - and at that point, Goldfinch * ... clever code for capturing interrupt and register state[/url], "borrowed" ... after a HALT you know you're in IM2 mode. ( ...Mistake in the 128K technical FAQ?[url]http://www.worldofspectrum.org/faq/reference/128kreference.htm[/url] [quote]Memory banks 1,3,5 and 7 are contended.[/quote] Really? I thought i…
... [B]EI[/B] and [B]HALT[/B], then the IM2 routine will start ... />
I have some pencil-and-paper calculations of what could ... into the available CPU time, and they're made a lot ...Tricks with IN 31It's generally considered unwise to use a Kempston joystick's fire button to start a game, because the floating bus effect can make arbitrary data ap…
... Kempston interface is disconnected, and I read IN 31 ... the interface is connected, and I read IN 31, ... But all modern interfaces (and all ZX emulators) return ... also real AMIGA MOUSE and this device set also ... 31 after HALT instruction (or at begin of IM2 routine)< ...
