exxos's Atari, Amiga & retro forum

It's not unusual.

I have found the SPI clock wasn't 20MHz as I selected. It was in fact running at 12MHz. The PICO derives the SPI clock from the USB clock, which is fixed to 48MHz. I found a way to increase the SPI clock, but there is so much noise on the bus, it fails to go above 16MHz. Nevertheless. this small increase takes the transfer rate to 751 KB/s at 250MHz cpu clock. I can't run the cpu any higher than that with the increased SPI speed. So, without a PCB designed, I don't think I'll be progressing on the transfer rate. I'm happy running the PICO at a clock of 125MHz, which yields a transfer rate of 683KB/s.

Currently looking in to RTC - would be nice to know how ICD implement their clock - anyone know anything about this?

You may need to adjust pull-up resistors on the SPI bus for 20 MHz SPI, and be careful when using SD-Card break-out boards, as some of them have voltage converters/dividers which are not needed for the Pico using 3.3V logic.

Don't know about ICD clock, but Ultra Satan clock is re-implemented in ACSI2SD.

You may also take a look at: https://github.com/carlk3/no-OS-FatFS-SD-SPI-RPi-Pico

dad664npc wrote: 29 Oct 2022 05:11 I'll gladly share my design if there is interest.

I'd be interested!

I'm still using an old ACSI2STM that I veroboarded up ages ago and whilst I meant to re-do that as a proper PCB, my first design failed and I haven't had time to go back to it.

I'm a sucker for somethig new, though, so if you're happy to share you schematic and your software, I'll try to put together another PCB.

Cheers,

BW

Badwolf wrote: 01 Nov 2022 11:29

dad664npc wrote: 29 Oct 2022 05:11 I'll gladly share my design if there is interest.

I'd be interested!

I'm still using an old ACSI2STM that I veroboarded up ages ago and whilst I meant to re-do that as a proper PCB, my first design failed and I haven't had time to go back to it.

I'm a sucker for somethig new, though, so if you're happy to share you schematic and your software, I'll try to put together another PCB.

Cheers,

BW

I'd also be interested in this...and I have a couple of 'spare' Pico boards which I could use ... ;)

Here you go

https://github.com/gotaproblem/ST_HD_Emulator

Feedback would be appreciated

dad664npc wrote: 02 Nov 2022 04:13 Here you go

https://github.com/gotaproblem/ST_HD_Emulator

Feedback would be appreciated

Cool. Many thanks!

I see you've used kicad for the schematics. If you could chuck in the SCH file it'll save me having to transcribe it again. :thumbup: :P

BW

done

dad664npc wrote: 02 Nov 2022 13:18done

:thanksblue:

BW

thanks :)