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A 386 PC for Your RP2350

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51–55 of 55 posts

Re: A 386 PC for Your RP2350

#51
post #38

Earlier quoted context omitted.

The PIO are pretty great and not niche. Almost any embedded application needs mixed signal interfaces. You could say embedded applications are niche, but not that embedded applications needing mixed signal interfaces. A serious warning: read the RP2350 errata carefully. You may be better off buying old 2040 inventory.

> read the RP2350 errata carefully Even the latest rev? Can you elaborate a bit?

The smart engineer always reads the errata carefully.

Re: A 386 PC for Your RP2350

#52
post #18

Does it emulate RS232 ports and printer ports as well ? I did'nt find anything. Then it would be possible to reuse old embedded equipment.

No, it doesn't. Also this doesn't emulate ISA bus, where one could plug one of those "multi-io" cards to get rs232/printer ports. Which is a shame. There are plenty of GPIO pins to fit full ISA on RP2350 (at least on "B" variant), and those GPIO are supposedly 5V-tolerant (with sufficiently recent silicon revision). So hardware-wise, it's just a matter of wiring up an ISA slot directly to the RP chip.

This could be useful on its own to create an ISA-over-USB bridge in conjunction with either a kernel driver or a user-mode PC emulator.

Re: A 386 PC for Your RP2350

#53
post #44

Holy cow, a 386 with VGA and SoundBlaster on a $1 MCU? I recall VICE emulating the Brotkasten on 386 PCs some thirty years ago, later UAE doing it for Amiga. How long til my currently running system (anno 2016) is being emulated?

Either "already" or "not any time soon", depending on how you count. Already - because you have VMs and backwards compatibility. As long as you keep using Intel x86_64, your apps would run, no emulation needed. Or you can use the VM. Not any time soon - because the computers are not speeding up that fast . 10 year old computers are still being used today, and even the latest CPUs are not orders of magnitude faster. S…

16-bit x86 code dependent on interacting with real hardware under precise timing doesn't always work well in a VM.

Re: A 386 PC for Your RP2350

#54
The problem is PC programs assume 640kb of RAM and the RP2350 has 512kb + 16kb cache SRAM so anything that goes past that has a sudden 40 cycle access delay.

So even if you account for the RP2350 being 6 times faster than the RP2350, I think the emulation would randomly start to stutter a lot in certain circumstances waiting to access that part of the memory.

Re: A 386 PC for Your RP2350

#55

Looks like it can even run Windows 96. Incredibly cool. I'll have to try if it runs my old Slackware kernal 1.2.13 some time. I used it with a 4MiB, 25Mhz 386 DX back in the time, so it should.

I don't know if they have some kind of magically genius caching system but the chip only has 512kb of SRAM and a little cache and the rest has to be managed by flash memory which is like 30+ times slower so I dunno about the performance of that.
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