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I got almost all of my wishes granted with RP2350

(dmitry.gr)
700 points elipsitz | 3 comments | 08 Aug 24 13:03 UTC | HN request time: 0.007s | source
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tecleandor ◴[08 Aug 24 15:43 UTC] No.41192751[source]▶
Not off topic but a bit tangentially...

How difficult would be emulating an old SRAM chip with an RP2040 or an RP2350? It's an early 80s (or older) 2048 word, 200ns access time CMOS SRAM that is used to save presets on an old Casio synth. It's not a continuous memory read, it just reads when loading the preset to memory.

I feel like PIO would be perfect for that.

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1. HeyLaughingBoy ◴[08 Aug 24 15:50 UTC] No.41192836[source]▶
If it's not an academic question and you have an actual need for the SRAM, what's the p/n? I have some old parts stock and may have what you need.
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2. tecleandor ◴[08 Aug 24 17:03 UTC] No.41193762[source]▶
Oh! Thanks!

I wanted to do a clone or two of said cartridges, that use, IIRC (I'm not in my workshop right now) a couple Hitachi HM6116FP each.

I've also seen some clones from back in the day using a CXK5864PN-15L, that's 8 kilowords, and getting 4 switchable "memory banks" out of it...

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3. HeyLaughingBoy ◴[08 Aug 24 19:28 UTC] No.41195260[source]▶
Thought I had more than this, but it's been literally decades...

I found (1) HM6116, (4) HM65256's (1) HM6264 and wonder of wonders, a Dallas battery-backed DS1220, although after 20+ years the battery is certainly dead. All in DIP packages of course.

And a couple of 2114's with a 1980 date code! that I think are DRAM's.

If any of this is useful to you, PM me an address and I'll pop them in the mail.