Search found 99 matches

by Ped7g
Fri May 24, 2019 6:20 am
Forum: General
Topic: How low is too low?
Replies: 4
Views: 783

Re: How low is too low?

esx calls don't need RAM (except stack must be valid upon entry, not sure about its size, would rather play it safe and have 50B at least there, but maybe it's just 2-4B needed before ROM pages its own scratch RAM for its internal stack ... I don't have board to try). So for ESX calls you need (AFAI...
by Ped7g
Fri May 03, 2019 5:34 pm
Forum: Introduce yourself
Topic: zx spectrum next
Replies: 29
Views: 3488

Re: zx spectrum next

You can still do the like-full-screen video by reading compressed data (especially if not aiming at 50/60fps), but if you want just to trivially push raw pixel data from SD card to RAM, then you are correct, it's too slow, even in the 14 (~10) MHz mode. The wolfenstein3D doesn't relate to the speed ...
by Ped7g
Sat Apr 06, 2019 6:18 am
Forum: Introduce yourself
Topic: Hello from Washington State
Replies: 4
Views: 473

Re: Hello from Washington State

And there's the decision to run second kickstarter to just produce another batch of the cased units - after the current KS is finalized and everything is shipped and done. I.e. hopefully around that June/July they will start to prepare for second campaign (this time without any serious research/deve...
by Ped7g
Thu Apr 04, 2019 12:31 am
Forum: Introduce yourself
Topic: zx spectrum next
Replies: 29
Views: 3488

Re: zx spectrum next

Maybe one more comment about "does the DMA support full screen animations at 50 frames per second? that would be 50x48kb =2.5mb per second from the sd memory device is this possible?" I'm kinda puzzled by this one, what you mean by full screen animation, for me full screen animation is when the comp...
by Ped7g
Thu Apr 04, 2019 12:20 am
Forum: Introduce yourself
Topic: zx spectrum next
Replies: 29
Views: 3488

Re: zx spectrum next

Hi Roger, I will try to add on some of those questions... is there a technical manual coming for it? The project on kickstarter was presented as "open source". So theoretically not only technical manual is coming, but whole scheme and firmware, etc. Then again over time I realized some people have d...
by Ped7g
Sat Mar 09, 2019 8:16 am
Forum: ZX Spectrum Next
Topic: Had no trouble reading the specnext group
Replies: 15
Views: 2217

Re: Had no trouble reading the specnext group

That will not fix the facebook... :)

I mean, I can see your point, then again this forum is already available, yet ...
by Ped7g
Wed Feb 27, 2019 4:29 pm
Forum: Software
Topic: HW Sprites and how to use them
Replies: 6
Views: 1067

Re: HW Sprites and how to use them

Thanks very much for this valuable and elaborated input. In the end it seems to drill down to bit fiddling and optimization depending on the available registers. I must admit that I was silently hoping that there is some kind of HW support available that I've overlooked. With latest extensions of S...
by Ped7g
Fri Feb 15, 2019 12:06 pm
Forum: Introduce yourself
Topic: Greetings from Malvern
Replies: 12
Views: 2959

Re: Greetings from Malvern

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 ...
by Ped7g
Thu Feb 14, 2019 3:10 pm
Forum: Introduce yourself
Topic: Greetings from Malvern
Replies: 12
Views: 2959

Re: Greetings from Malvern

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...
by Ped7g
Thu Feb 07, 2019 6:45 pm
Forum: Software
Topic: How to detect that DMA transfer is finished
Replies: 14
Views: 1964

Re: How to detect that DMA transfer is finished

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...