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This page shows a low cost Xilinx FPGA emulating the classic 6502 CPU:

https://forums.xilinx.com/t5/Xcell-Daily...a-p/798317

The 2nd photo, showing a Spartan 3 doing the job, reminds me that this is more or less the same chip that Darryl used in the 405 line NTSC colour version of the SCRF converter.
That's interesting. The 6502 is a very simple CPU even by mid '70s standards, so I suppose it's not so surprising that it needs few FPGA resources to replicate one.
We use the Xilinx Artix and Kintex range of FPGAs and related devices where I work and the amount of logic that these can implement is really quite impressive.

John
An interesting point about this 6502 emulation is that it interfaces directly to the outside world. Though I wonder how they got around the fact that all logic from back then was 5V while these FPGAs can't tolerate more than 3.3V.

8051 class cores are widely available too. Another simple CPU.
(24-10-2017, 07:24 PM)ppppenguin Wrote: [ -> ]An interesting point about this 6502 emulation is that it interfaces directly to the outside world. Though I wonder how they got around the fact that all logic from back then was 5V while these FPGAs can't tolerate more than 3.3V.

8051 class cores are widely available too. Another simple CPU.

Not that many pins and you can get packs of level converters, e.g. the TI TXB0108, 8-bit bi-directional translator with two Vcc pins - one for 3.3 and one for 5V.

GBP 1.13 ea from Farnell
Thanks Nick. Useful little beastie that I didn't know about.
[attachment=16814]
Not a 6502 I have these if any good to someone.
It is interesting in their use of the Vic20. I bought one of these very cheaply years ago, finding the access to the 6522VIA very useful for interfacing. I probably need to check it out and reform a few caps as it just sits in storage. I found the 6502 easy to use (program). Even the simple processors now seem daunting with their multiple registers and modes, plus attendant bible for reference.
Murphyv310, do you still have those chips floating around?
Sure do.
Yours if you want them, I'll never have a use for them.
If it's the 6502 processor you're looking for, there are quite a few on ebay from £5 upwards.