-
designing a computerHi everyone! I am designing a 4 bit computer and i need some advice, is this a good instruction set? [CODE] BINARY OPCODE DESCRIPTION 00000 nop…
... and continue to the next instruction.
DEC - Decrement a register ... wish to add NOP and HALT instructions, which are trivial as ... to the next or same instruction respectively. None of these are ... something vaguely like a microprocessor instruction set. -
Assembly Programming for IDIOTSOk are there any websites guides for what opcodes do in a z80 or books... but for really really thick people like me :-) Something along the lines …
... for each instruction. For example, it tells you HALT will halt the CPU ... until an interrupt occurs. (Thus HALT is ... -
Assembly Programming for IDIOTSOk are there any websites guides for what opcodes do in a z80 or books... but for really really thick people like me :-) Something along the lines …
... say to never use IM instruction ;) )
Now you can ... to screen.
HALT is a instruction that tell computer towait ... -
LCD interfacingHas anybody interfaced [url=http://mdfs.net/Info/Comp/LCD]an LCD[/url] to a Spectrum? I'm toying with putting together an interface, a small 32x8 dis…
... /> WRINST EQU C0h ; write instruction
WRDATA EQU C1h ; ... br /> CALL INSTR ; output instruction
LD ... send the message
HALT ; all stop
... br />
INSTR: ; output instruction
CALL DELAY ; wait for ... -
yeah - unix for zx spectrumI started a new hobby project. An operating system for ZX Spectrum. A unix clone. Talked to my friend about it and he asked me what if after I'm done…
... function pointers (the "jp (ix)" instruction takes 8 cycles), slow 16 ... be replaced with a single instruction "rlc b"; the end is ... only grinds things to a halt; I can only see these ... keys in a single IN instruction (just clear more than one ... -
Assembly help: EQUCan anyone explain in duffers language the purpose of the EQU term in assembly? I found this info in another thread: EQU: Equate a name to a specif…
... /> MyName .EQU 1000
HALT[/B]
and ... /> MyName .WORD 1000
HALT[/B]
With ... HL,1000.[/B]The HALT istruction will appear ... the number 1000, so HALT will appear at adress ... takes the value of next instruction
memory address. ... -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... CPU is locked using DI / HALT. If I press the reset ... , and as the last instruction before the HALT, SP is set to ... -
Definitive list of games incompatible with +2A/+3 and of compatible versions (if any)I am trying to compile the definitive list of games which are incompatible with the +2A and the +3 and of their compatible versions, if they are pres…
... simply added a PAUSE 0 instruction in the original loader so ... upon loading the system will halt to a black screen - thus ... -
RAND USR that doesn't work in emulators and clonesEons ago, I "discovered" a strange RANDOMIZE USR. This is it: [b]RANDOMIZE USR 46578[/b] Using it on a genuine ZX Spectrum rubber key or Plus model,…
... the HALT (looped) opcode fetch. In my opinion, the PUSH DE instruction ... satisfied:
1) the /HALT state is exited after the ... -
automatic relocating of non-relocatable codeI was pondering upon the problem of changing absolute addresses used by CALL, JP, etc. when code is moved, without reassembling at the new location; …
... enabled):
[code]
halt
di
dec sp ... patch then inserts a JP instruction to the code at the ... -
Up/Down Left/Right scrollCan anybody give a newbie some pointer to simple one char scrolling by pixel? I've looked at a lot of resources, but as you can imagine, it's all a …
... /> ld a,0
face_loop0 halt
push af
add ... tell you when.
face_loop0 halt
;when you know about ...
;I use the DJNZ instruction to decrement B and loop ... -
Which Speccy game had best border effectsIn truth, I'm just trying to remember a game from my youth, and the amazing border effect during pause is the only thing I can clearly recall about i…
... if you can use a HALT to wait for it.
instruction to finish executing before it ... . Even if the last instruction was a HALT, that works like a ... -
Which Speccy game had best border effectsIn truth, I'm just trying to remember a game from my youth, and the amazing border effect during pause is the only thing I can clearly recall about i…
... if you can use a HALT to wait for it.
instruction to finish executing before it ... . Even if the last instruction was a HALT, that works like a ... -
Which Speccy game had best border effectsIn truth, I'm just trying to remember a game from my youth, and the amazing border effect during pause is the only thing I can clearly recall about i…
... if you can use a HALT to wait for it.
instruction to finish executing before it ... . Even if the last instruction was a HALT, that works like a ... -
Disable interrupts?Well, I've read the bits from the David Webb book about interrupt modes and (vaguely) appreciate the principles behind having a vector table, after r…
... a single EI or DI instruction :)
So yes, you ... .
An useful instruction is HALT - it makes that processor to ... />
The simplest use of HALT when you don't have ... is:
A) Execute HALT which makes Spectrum start to ... -
28-character wide multicolour(ish) on 48k SpectrumLong-time lurker here... I've always been interested in rainbow effects on the 48k Spectrum, mainly from a perspective of "Just what [I]would [/I]ha…
... LD a,(22528 ) --a contended instruction to keep everything in sync ... trivial to lost sync, because HALT is a serie of NOP ... machine state, but a contended instruction makes it on sync. I ... to use a long contended instruction now and then to keep ... -
question re. STR$ bugCould someone point me to whereabouts in the ROM this goes wrong? [code]PRINT PAPER 5;1;STR$ 234[/code] (Only the "1" prints in cyan.) It's not the m…
... "K" the current channel. The instruction RES 5, (FLAGS) at address ... the routine should do a HALT if channel "K" is in ... -
64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... the middle of a long instruction (like an LDI), it'll ... sure you've always used HALT before the interrupt occurs, you ... up to 3T as the HALT waits in 4T cycles, like ... -
64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... value 243
;so the instruction being read will be 24 ...
M2
HALT
LD (StoreSP),SP
64x48 full colour graphicsHow feasible is this? Could an interrupt-driven routine be used to, for example, fill the top two thirds with a 64x32 blocky picture and leave the bo…
... 243
EI ;so the instruction being read will be 24 ...
M2
HALT
LD (StoreSP),SP
Using RST 16 and udg flickerHi there! I'm using UDGs and RST 16 to make a simple canyon bomber game. I've got the game mechanics working ( finally ) but now I'd like to make …
[QUOTE=Morkin;659467]At first glance it looks smoother and has less flicker, even without worrying about interrupts[/QUOTE]
Try to execute instruction "HALT" inside your main loop, just before you start to clear and draw sprites.Code execution logging/profilingAs revealed in [url="http://www.worldofspectrum.org/forums/showthread.php?t=41666"]this thread[/url], I'm adding support for reading code execution l…
... , tab separated values for each instruction executed...
[#] [Address] [Bytes ... useful too.
Suggest that HALT is NOT expanded to 1000s ...Video generation using a CPUWe know it is possible to generate a video signal using a CPU, and this technique was often used on low-end computers in the early 1980's (for exampl…
... CPU gets fed a NOP instruction, so it does nothing for ... opcode for HALT, and rather than a NOP that instruction is executed ...The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…
A continuation of the instruction trace:
[CODE]
... RAM
SRC PC Instruction
0 0059 JP #0321 ... (#5B81),HL
0 032C HALT
0 0038 PUSH HL ...Can a guy that traveled on the short bus learn machine code...Hmmm So after some soul searching I figured it was time to finaly nail spectrum machine code. Its so frustrating to sit infront of a basic listing w…
... you think it through, an instruction that did LD A,(PC ... end up putting whatever the instruction code for LD A,(PC ... use (in a three byte instruction, for example, there are four ... mistake of looking at the Halt opp. lol my fragile mind ...A new full-screen bicolor engine called NIRVANA[I]OK, there's something I need to clarify first: Nowadays if you write [B]"multicolor"[/B] everyone assumes it refers to "multicolor 8x1" (an attri…
... is already the first instruction executed by the engine ... [CODE]
// ----------------------------------------------------------------
// Execute HALT (wait for next frame).
//
// HALT can be used to avoid ...Using the stack to blit bufferI was using a ldir to blit my back buffer to the screen RAM, and it was working pretty well if not rather slow. After reading about using the stack …
... routine is just the one instruction, 'RET'. It doesn't even ... frame you do EI then HALT.
For this method ... when it comes to a HALT), but if timing is critical ...FUSE serial communication sample anyone?Hi, in [URL="http://manpages.ubuntu.com/manpages/precise/man1/fuse.1.html"]FUSE man pages[/URL] one finds switches for serial comms. By using --inte…
... byte command). RST nn and HALT. While RST would work under ... need to be in ROM, HALT would prevent debugging IM2 dependent ... gdb-z80-stub to use HALT command for breakpoint and rewiring ... the breakpoint with another instruction (such as HALT) as there is for ...
