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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 ... you cannot trigger an interrupt manually (but you ... simulate" an interrupt by calling directly the interrupt handler, for ... /> This is for maskable interrupts. For non-maskable interrupts, the bare Spectrum ... -
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…
... triggered and acknoledged interrupt causes the Z80 to ... " an interrupt by calling directly the interrupt handler, for ... /> This is for maskable interrupts. For non-maskable interrupts, the bare Spectrum ...
Does the interrupt push the registers and the ... -
Opus DiscoveryWould anyone have any materials about programming the Opus Discovery disk? I know it overrides ROM and uses microdrive commands, but I am more into b…
... somewhere to RAM and raise interrupt when done?)
4. If ... floppy controller, is done by Non Maskable Interrupts and the JP (HL ... -
Hacker Chris' Christmas Demo doesn't work[url=http://www.worldofspectrum.org/infoseekid.cgi?id=0007314]Christmas Demo[/url] .z80 file from WOS doesn't work for me. I tested in Fuse and SpecE…
... in a HALT instruction with maskable interrupt disabled.
Is the ... -
Address bus contents (i.e. PC) during execution of HALTI'm wondering if anyone can tell me what's placed on the address bus during execution of HALT, beyond the initial M1 cycle. The Z80 user manual state…
... [I]before[/I] the interrupt is acknowledged, and that the ... the return address of the interrupt handler. Firstly, if the ... seem simpler in the interrupt acknowledgement not to deal ... />
For NMI and maskable interrupt acknowledgement, it contains:
Contended memory article on WikipediaYeah, apparently there's one. https://en.m.wikipedia.org/wiki/ZX_Spectrum_Contended_Memory [quote] However, the ULA must wait for a Z80 read or wr…
... to the display on interrupt, as the Spectrum maskable interrupt was generated by ...New discovery on Z80 interrupts.This is to announce the discovery of a new, hitherto unknown, behavior of the RETI and RETN instructions. As everyone knows, the maskable interrup…
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As everyone knows, the maskable interrupt can be enabled and disabled ... the state of the interrupt enable flip-flops (IFF1 ... accept this kind of interrupt directly after an EI ... defer the acceptance of the maskable interrupt for one instruction, but ...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…
... from the basics up to "non maskable interrupts" etc.
If ...ZX48k terminal...Hello everybody, I thought someone might help me. I connect my good old ZX48k to my PC via serial (IF1) link, and I was trying to write a little term…
... the BASIC is actually the maskable interrupt service routine. The keyboard scanning ...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…
... . Interrupts are disabled while a maskable interrupt is being serviced, to make ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
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IFF2 will maintain the maskable interrupt enable bit even if NMI ... .
Clearing IFF1 disables maskable interrupt at NMI time. If another ... final one exits the true maskable interrupt state is maintained by RETI ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... IFF2 obviously break the correct maskable interrupt status bit when nested, and ... IFF2 can potentially re-enable maskable interrupts in a parent NMI ...Program sizeI am typing a basic program into a ZX and I need to find out exactly how much memory it is using. Is there a way to calculate this? :confused:
... of ROM and allows for maskable and non maskable interrupts to use the ...Interrupts details questionSuppose I am writing a game and I want to use interrupts to measure time, draw the screen without flicker, maybe to poll keyboard etc. What kinds of …
... interupts are concerned, the NMI non-maskable interupt was never properly implemented ... ROM. All other types, ie. maskable are generated 50 times a ...Nesting NMI'sz80-undocumented (.pdf) page 20/21 [from [url]http://www.myquest.nl/nowind/?q=node/10[/url] ] suggests that IFF1 is not copied from IFF2 if NMI's are…
... on DI and upon accepting interrupt. Maybe you made a typo ... would lose the state of maskable interrupt upon nested NMI. What happens ...for a stupid: what?s NMI?erhm, yes, I?m not familiar with it... :rolleyes: I know the function of a hardware ?snapshot? button from Didaktik M/Kompakt, but I?m not familiar…
... to do its dirty [B]interrupt[/B] chores when the voltage ... [/B]
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The interrupt routine should end up with ... whether to accept an ordinary maskable interrupt or not).
The ...Regarding the interface with USB port[url]http://www.octocom.es/reuniones/art_madridsx07_11.html[/url] [url]http://velesoft.speccy.cz/kmouse/km-doc/kempston_mouse_turbo_interface/km-t_2…
... that design with regard to maskable interrupt processing from the Z80? ... getting garbled if the maskable interrupt rate was too high, ... CTC) never releasing the interrupt daisy chain. (This wasn ... what was happening, during an interrupt acknowledge by the Z80, ...Regarding the interface with USB port[url]http://www.octocom.es/reuniones/art_madridsx07_11.html[/url] [url]http://velesoft.speccy.cz/kmouse/km-doc/kempston_mouse_turbo_interface/km-t_2…
... that design with regard to maskable interrupt processing from the Z80? ... getting garbled if the maskable interrupt rate was too high, ... CTC) never releasing the interrupt daisy chain. (This wasn ... what was happening, during an interrupt acknowledge by the Z80, ...NMI : especially PitersHello Piters, here the link to your NMI-button. [url]http://members.tripod.com/~piters/nmibutto.htm[/url] I don't understand your reason to place …
... ]The state of IFF1 (the maskable interrupt flip flop) is restored from ...How does interrupts work?I am a little confused regarding the interrupts on the Spectrum. If I have some hundred bytes of machine code started with, say, [B]RANDOMIZE USR 300…
... by counting the number of maskable interrupts as they occur every ... [/B] HALT Wait for a maskable interrupt.
DEC BC Decrease the ...Input/Output on Edge ConnectorI would like to sense a pulse on the data bus via the edge connector, i.e. on or off. How do you decide what port it is on? I would also like to send…
Maskable interrupt acknowledge.There's a special ... pay attention to M1 then interrupt acknowledges can do really strange ...InterruptsI need help emulating interrupts. My z80 core currently emulates all un-prefixed opcodes and the CB opcodes. I thought I would start on emulating co…
... think indicates when maskable interrupts are disabled. When a maskable interrupt occurs, the ... z80 automatically disables further maskable interrupts. The ... well. Just run the interrupt code every time something causes ...Fast screen writesI wondered what the faster than LDIR methods of writing to the screen were.
... immediately after the vertical blank/maskable interrupt. That way, not only are ... yourself. Write a very short interrupt routine that just does a ... (I). You can do your interrupt stuff after drawing the screen ...Fast screen writesI wondered what the faster than LDIR methods of writing to the screen were.
... immediately after the vertical blank/maskable interrupt. That way, not only are ... yourself. Write a very short interrupt routine that just does a ... (I). You can do your interrupt stuff after drawing the screen ...A question about M1 cyclesI'm writing an interrupt routine that, after the usual register pushes, will jump to a location of my choice with a [b]JP (IY)[/b] instruction. If I…
... device doesn't want a maskable interrupt to ever be missed, it ... M1 cycle that acknowledges an interrupt (at this point, more complex ... , depending on what kind of interrupt mode they are designed to ...SAVEing without waiting for keypresshello, here's question for y'all. is there a way in BASIC to bypass the "Start tape, then press any key" prompt when SAVEing an array? sorry if it'…
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DI ; 32616 243 disable maskable interrupt
JP $04FE ; 32617 195 ...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…
... scheduler is invoked by a maskable interrupt).
The only ... ever need to know if maskable interrupts are disabled is ... an NMI can cause an interrupt while interrupts are disabled, ... You will always know that maskable interrupts are disabled within a ...Why doesn't my routine work?I have a "level" defined by 504 bytes (28 squares across x 18 squares down) I'm trying to write a routine that will take an X,Y coordinate in pixels…
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; THE 'MASKABLE INTERRUPT' ROUTINE
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; This routine ...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; …
Surely this is a havoc-free zone?! The maskable interrupt updates FRAMES, not SEED, and doesn't make any permanent alteration to SP. All my tests have been havoc-less.NEW KEMPSTON interface for ZXHi. Lotharek has released a new KEMPSTON interface for people who doesn't need AY on-board and want to have some really small device. [url]http:/…
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The interface is "[b]interrupt-friendly[/b]". It doesn't ... selected. Games that redirect the maskable interrupt and assume that the data ...
