The ZX Spectrum Next forum

I'm still reading up on all the forum posts, etc. But as I understand it the SID was dropped primarily because it was too big for the FPGA. But that was before the specs were changed to the larger FPGA. No, the FPGA was bumped up as stretch goal during kickstarter, so it's known to be larger SPX16 ...

It's not part of the "Next" FPGA core, which Malvern seems to understand, as he was writing about summoning SID into FPGA by ... magic probably... :) ... or more likely by writing your own core, which involves probably some VHDL coding and mixing together different open source firmwares from other p...

Hm... with interrupts you have to decide on the priorities and what happens when there are two in parallel. The DMA inhibits interrupts, so in burst mode producing audio it may make interrupt stumble by couple of cycles (the memory read is 2T when DMA is configured to fastest mode ... if ZXNDMA oper...

You have enough reasons to wait until the compilation does finish...

On original Z80DMA any write into DMA registers will stop current transfer (but it hadn't burst mode like ZXNDMA, so I'm not 100% sure if it does apply). You can stop the DMA by sending a DISABLE_DMA command. Then you could read the registers to find out where the DMA is so that you could restart i...

I think there will be multiple tools for Next available, some leaning more toward windows, some more toward being portable... (I personally have only linux machines at home, so my preference is obvious)... and I don't think there will be single "go to" package suited for everyone, as people prefer d...

If DMA is used in burst mode for audio for example. Is it possible to interrupt DMA in order to to use DMA for byte block transfer (continuous mode) and then continue to use DMA in burst mode for audio? On original Z80DMA any write into DMA registers will stop current transfer (but it hadn't burst ...

Theoretically yes, the NextRegister 0x05 should contain the info ( https://www.specnext.com/tbblue-io-port-system/ ). In BASIC it would be something along: OUT 9275,5 (selecting NextReg 05 on I/O ports), x = IN 9531 (reads value) I can't recall enough of BASIC syntax to show full working example, al...

Somehow I never noticed that SQL and CIRCLE are the same key :) This must really be the best looking spectrum yet! Thanks for the update! Do you mean SQR :) I did indeed! I bet you can't guess the sort of thing I was debugging today :) Machine-learning neural-networks optical-character-recognition ...

I don't think they are capable to operate in parallel .. at least the original Z80 DMA was inhibiting the CPU completely IIRC (it's already quite some months since I read through that data sheet, so I'm not sure).