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replacing vintage CPU with MCU emulation [message #9902] Fri, 06 May 2022 06:55 Go to next message
lynchaj is currently online  lynchaj
Messages: 1080
Registered: June 2016
Senior Member
Hi
This is just a thought experiment. I was wondering if it would be possible to replace a vintage CPU like a Z80 with an MCU based emulation board.

What I mean by emulation is a cycle-exact replacement of a vintage CPU with an MCU based board in the existing socket such that any legacy software would run unaffected.

For instance, build a modern ARM MCU board with a 40 pin socket interface that can be swapped out for an actual Z80 and everything would continue as before.

Sort of a local ICE board but small enough to fit on the main board without ribbon cables, etc.

I have seen 6502 replacements using FPGAs so this is kind of similar but using a modern MCU instead.

Thanks, Andrew Lynch
Re: replacing vintage CPU with MCU emulation [message #9903 is a reply to message #9902] Fri, 06 May 2022 08:45 Go to previous messageGo to next message
e2k is currently offline  e2k
Messages: 33
Registered: June 2021
Member
It has been made for a 68000:

https://www.buffee.ca/

you can see a picture here:

https://amitopia.com/buffee-is-real-and-tf1200-is-coming/
Re: replacing vintage CPU with MCU emulation [message #9904 is a reply to message #9902] Sat, 07 May 2022 04:48 Go to previous messageGo to next message
will is currently offline  will
Messages: 213
Registered: October 2015
Senior Member
Another similar project for the Amiga is PiStorm which is a 68000-pin compatible board that uses 68K emulator software on a raspberry pi to replace the CPU, as well as adding fast RAM, virtual SCSI and graphics hardware using the pi's onboard resources. There's at least a couple of different soft-68K cores the project can use -- one is the Musashi 68K which works as an interpreter and gives CPU performance equivalent to a 100--125MHz 68030 (23,000 Dhrystones, 24 MIPS). A second is Emu68 which is a 68K to ARM just-in-time (JIT) compiler which is ... much faster (795,000 Dhrystones, 830 MIPS).
Re: replacing vintage CPU with MCU emulation [message #9905 is a reply to message #9904] Sat, 07 May 2022 09:16 Go to previous message
scruss is currently offline  scruss
Messages: 62
Registered: December 2015
Location: Toronto, Canada
Member

This isn't exactly pin-for-pin compatible, but the PiTubeDirect emulates processors/RAM at the end of the BBC Micro's 2 MHz "Tube" bus. The range of processors is pretty impressive, and they all run bare-metal on a Raspberry Pi.

These leaves one with the considerable problem of actually getting a Raspberry Pi, though ...


> Does anyone know what each of the pins on the 6502 CPU chip in the Apple II Plus does?
They all plug into the socket on the motherboard to keep the chip from drifting away. - c.s.a2 FAQ of yore
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