Reply to post: Re: 98% ZX Spectrum look a like

ZX Spectrum Vega+ blows a FUSE: It runs open-source emulator

Lee D Silver badge

Re: 98% ZX Spectrum look a like

Most ZX Spectrum ULA chips can be tapped to produce a composite video signal.

It takes a bit of soldering, but it can be done, and there are FGPA versions of the ULA now if you really want to custom-build it.

Even the original RAM chips have probably died by now and are easier to just replace with one large chip than the multiple Upper/Lower RAM chips of the original.

Basically a Z80 of any fashion, maybe one or two custom chips / RAM chips, and you could easily do such. The expansion connector was literally just the Z80 I/O pins for certain ranges brought out to the connector, IIRC (even the Interface 2's ROM cartridges were nothing more than a direct memory chip sitting on the right exposed address lines).

The problem is that almost all the components fail over time - the ULA, the RAM, the keyboard membrane, etc. and they are what made the Spectrum unique. The bits that don't fail (the Z80 itself, that's about it) are off-the-shelf and bog-standard.

It would be easier to just ditch the entire interior and stick in a Pi Nano or Arduino. With the latter, you could easily interface with a real Z80 (timing would be a pain in the arse but manageable), and expose the I/O lines directly for peripherals.

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