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Program Counter question - please readSorry if this is in the wrong forum, but please read it through anyway - see on the FUSE PSP emulator I asked the author if he'd add an option to pri…
... print the contents of the Program Counter on the screen (away from ... tell if a game or program had crashed because the PC ... remain constant with a running program, but I want to check ... -
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] ; ***********…
... dont know where the program counter is when im2 is ... .
; Have a counter, when it reaches target, ...
;prepares interrupt handling
initIM2:
; 8 = RO:Pause Counter
; 9 = Pause Target, ... -
Sync-buzzer, interrupts and general confusionBeen wittering on about this in the Misc group, but thought it was best discussed here. Basically been trying to recreate the Sid-Sound effect from A…
... RETI
Description. Pop the program counter (PC) off the stack. This ... the processor to the interrupt recognition status it had ... thinking that if an interrupt keeps occurring between the ... * instruction. That means no interrupt can happen until after the ... -
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] ; ***********…
... jr Start
; **** START INTERRUPT ROUTINE ***
MainLoop:
program counter is when im2 is ... /> reti
; **** END INTERRUPT ROUTINE ***
Start:
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] ; ***********…
...
; **** START INTERRUPT ROUTINE ***
MainLoop:
program counter is when im2 is ... /> reti
; **** END INTERRUPT ROUTINE ***
MoveAndPrintSprite:
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…
... (for instance, z80_pc being the program counter which is a 16 bit ... some method of timing the interrupt frequency - and handily enough, each ... a counter, and when you reach 69888 then cause your interrupt and ...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…
... setting the interrupt handler up, as 90% of my program is written ... />
Any simple IM 2 interrupt routine I write myself (like ... after setting up the IM2 interrupt handler with the chip music ... br />
This causes the program counter to somehow end up at ...Program Counter question - please readSorry if this is in the wrong forum, but please read it through anyway - see on the FUSE PSP emulator I asked the author if he'd add an option to pri…
... do this, by monitor the Program Counter (PC) - it ...
D.[/QUOTE ... which is updated via an interrupt (as is the case with ... but not in the main program. This situation is both equally ... in a normal non-crashed program AND a crashed ...Tutorial - learn machine code in 30mins[B][I]Message from the moderators[/I] - bigjon has requested that readers' attention be drawn to a better version of this tutorial, one which is easi…
... list excludes the specialized PC (program counter, the 16 bit register that ... that the ULA generates an interrupt at the start of ... and respond by calling an interrupt service routine. Afterward it will ... arranges to run BASIC's interrupt routine so by default ...z80 emulator with converter ?Hi i am finding the old z80 emulator v2 or v3, dont remember. Some of these versions have the snapshopt to 1.45 converter that allows us to conver t…
... 2 emulation Off
Double interrupt frequency Off
Video ... Border colour 7
Interrupt status IM1, EI (IFF2 = EI ... (bit 8 is 0)
Program counter #10b4 Stack pointer #7514
Port 254 emulation problem. Help, please ...Sorry, but my english is not pepfect. I have a problem and need in professional help. I have developed hard-soft emulator of ZX Spectrum 48. The link…
... RAM or ROM. Xh:Xl - program counter
BRCS FROMROMDB_ ; else go ... /> COMDB: STS PORTF,ZERO ; Generate interrupt for videocontroller
LDI TMPH ...Add horizontal hardware scroll to ULA+In this case we must read a bit in the ULA+ for test if supported. And the future software that uses it must have to branch: 1. If hardware scroll i…
... use a 8 bits counter for scanline interrupt, ?why not from ULAplus ... , like hw scroll or scanlines counter interrupt so, ?why implement that and ... to enhance [I]any[/I] program.
Quite brilliant really ...How to safely maximise available memoryHi All, I'm toying with an idea that will require I have as much memory available as possible. I'm a little embarrassed I have to ask this tbh. As…
... genuinely have to have an interrupt routine (e.g. my one ... an interrupt does occur, it PUSHes the current execution address (program counter) onto ...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…
... timed event like an interrupt. A lot of modern ... maybe update a timer counter on the interrupt. It's what ... of the TV and the interrupt is simply a 'RET ... there so that an interrupt actually happens, so that ... command in your main program to wait and synchronise ...Simple explanation of interrupts (in the context of Z80/Speccy)I wondered if somebody on here could explain in simple terms how interrupts work on the Speccy and where interrupts are source from. Are they a natur…
... a triggered and acknoledged interrupt causes the Z80 to ... and you cannot trigger an interrupt manually (but you can ... "simulate" an interrupt by calling directly the interrupt handler, for ... Does the interrupt push the registers and the program counter on the ...Simple explanation of interrupts (in the context of Z80/Speccy)I wondered if somebody on here could explain in simple terms how interrupts work on the Speccy and where interrupts are source from. Are they a natur…
... ;632878]Does the interrupt push the registers and the program counter on the ... taken to handle the actual interrupt itself is almost certainly significantly ... the time spent in the interrupt routine. That's far more ...Simple explanation of interrupts (in the context of Z80/Speccy)I wondered if somebody on here could explain in simple terms how interrupts work on the Speccy and where interrupts are source from. Are they a natur…
[QUOTE]Does the interrupt push the registers and the program counter on the stack ... ? [/QUOTE]
Interrupt executes some ... code - interrupt routine.
The ...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…
... of each display line, an interrupt is generated by the ULA ... />
The address in the program counter now points to the first ... CPU then pauses until the interrupt is generated for the next ...Is there an SNA halt bug?Hello all, I noticed that some SNAs don't work on my emulator but they do work in almost everyone else's, SPUD fails with them too which is a tad sp…
[QUOTE=balford;709150]Ensure that you support IFF1 and IFF2 values correctly in your Z80 emulation, then the other important bits are as follows:
(Code in C# so bitwise comparisons a bit convoluted to keep the compiler happy)
...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…
... repeated NOP's until an interrupt is generated, which take 4T ... needs to complete before the interrupt is handled.[/QUOTE]
program counter to its previous value so ...How are LAST-K and FLAGS set on a Real Spectrum?Hi, I'm writing a Spectrum emulator and I've got Horace and the Spiders working (with the wrong colours and no sound) but when I boot into ROM non…
... handling the end of frame interrupt IMHO. The ULA triggers a ... maskable interrupt at the end of each ... Z80 responds by pushing the program counter onto the stack and jumping ...Solution for overwritten stack in 48k SNA filesIt has been known for quite some time now that the 48k SNA file format has one serious fault, which is described in the file formats section on the W…
... in a file separately, the program counter is pushed onto a stack ... 2 bytes of data (or program code) in RAM and therefore ... registers and memory, pops the program counter from the stack and then ...Multiple ROMsI'm mulling over the idea of a bit of hardware with a ROM in it, which has some commands that can be called by BASIC (like the old wafadrive star com…
A vexatious questionThis is kind of a follow-up to a question about RST #8 and hardware that I wrote in the development forum a while ago. To summarize that: certain ha…
... RST #8 - presumably when the program counter hits 0x0008 (i.e. an ...some debugger in emulators that is able to brakpoint when a mem address is accessed ?Is there a debugger (disassembler) available in some emulator that is able to stop (breakpoint) when a particular memory address is accessed ? For e…
... ) and to see where the program counter has stopped. In other words ...Interface 1 ShadowROM pagingI read the Interface Shadow ROM Disassembly book. I wondered how that rom calls the interface's rom paging mechanism. It doesn't! I learned there is …
... address Speccy fetches instructions. When program counter reaches 8 (error routine) or ...A DOS question, slightly OTI have an old laptop (a P75) which is great for Spectrum emulation (X128 ), and C64 emulation (CCS64), and I want to emulate the Atari ST, too. Now, …
... make a TSR-program.
This is a interrupt steered program which would ...How do i learn to programAll the years i had a computer the only one i could program was the Texas Instruments Ti99/4a and when using extended basic with its so simple sprite…
PC is short for program counter - without it the Z80 doesn' ...
