[Video] 16MHz hack, the next generation: AltRAM

[Badwolf]

Morning all.

It's been a little while since my last offering on the video front.

During this time I've been playing with the STE PLCC/DIP adapter again. I've put together an experimental little board and have been boring Exxos and Christian with RAM-related questions. Oh yes.

Needless to say, things did not go according to plan.





Mahna mahna,

BW

[exxos]

That MMU thing caught me out as well. You have to keep the RAM disabled until TOS boots, then when you install alt-ram you enable it as well.

[Steve]

Really enjoyed the video Thanks for the mention

I can't wait to get some ALT-RAM into my ST's because I just love FreeMint and ALT-RAM is a godsend for it. I didn't catch it but is your booster going at 16mhz with the ALT-RAM or 32mhz?

[Badwolf]

Really enjoyed the video Thanks for the mention

I can't wait to get some ALT-RAM into my ST's because I just love FreeMint and ALT-RAM is a godsend for it. I didn't catch it but is your booster going at 16mhz with the ALT-RAM or 32mhz?

Haha, cheers, Steve. I hoped you'd notice the tip of the hat.

Chip is switching 8MHz to oscillator/4, RAM is at oscillator speed. Current oscillator is ~66MHz.

I thought I couldn't get MiNT (1.19) to work. Then it started working and I don't know what I changed. Then it stopped again. It's odd. MultiTOS works fine. EDIT: I wonder if it could be related to my blocking of the 'E' line?

My AltRAM at present is kind of implemented in a 'stupid' configuration. It doesn't try to optimise timings to the CPU clock as one of the target cases for this board was to provide an independent RAM board for Exxos's H5 setup where no knowledge of the CPU clock is available.

In short, there's a lot more I could do to optimise things but none of them will happen without rewrite of the SDRAM controller code. It's right on the edge of its capabilities. Perhaps that'll sort out this odd MiNT incompatibility. I could also try 1.18, I suppose.

I've also got a little plan to try using latches instead of voltage buffers. Will probably need a jump to 4 layer to accommodate the extra space, but that's not a bad thing. Should very much simplify the logic too.

BW

[derkom]

"What an absolute shambles."

I did not expect to watch the whole video when I began, but it rapidly became essential viewing. Nice work.

[Badwolf]

"What an absolute shambles."

I did not expect to watch the whole video when I began, but it rapidly became essential viewing. Nice work.

Thank you, @derkom. I think you've just found the channel's motto.

BW

[Badwolf]

BW

[exxos]

Be interesting to try frontier on the 32Mhz CPU if you could post your frame counter version..

[Badwolf]

Be interesting to try frontier on the 32Mhz CPU if you could post your frame counter version..

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BW

[derkom]