4 ms·
Using an atmega kind of kills the fun, it is many times more powerful than the z80 "cpu"
by dmitrygr 3y ago
Using an atmega kind of kills the fun, it is many times more powerful than the z80 "cpu"
- shermantanktop 3y agoYou’d prefer the sweet, sweet pain of authenticity?
- varjag 3y agoFair to say that few would build a retro system for convenience.
- thatjoeoverthr 3y agoI think it’s literally the purpose of the thing like this.
- shermantanktop 3y agoThis happens with guitars, cars, houses…any item which has both historical and function value. The original owner of the item makes numerous small changes and repairs over decades which preserve and improve the functionality. They finally sell it off to a collector who reverts all the changes, degrading the functionality in order to restore some notion of authenticity. And sometimes they go further, fixing “mistakes” made by the factory. In this case, the functionality of a Z80 is so ridiculously outdated and obsolete that I suppose authenticity (and nostalgia) is really the only point.
- shrubble 3y agoThe suppprt chips would add a few more chips; the most basic z80 setup is 5 or 6 chips, but they are not as easy to find.
- noone_youknow 3y agoFor a simple 8-bit system such as this, even if “no GALs” is a requirement, all the chips one would need can still be bought today, brand new, and are still in production in one form or another (e.g Alliance SRAM, SST flash, 74HCT logic etc). Worth noting that 16V8 and 22V10 GALs are still being made too, and I’d argue that programmers for them aren’t exactly “outdated”. Not that I have anything against this design, I’m always happy to see a new SBC, though it could be argued that it still “hides” more of the bus inside the MCU than would perhaps be ideal.
- kragen 3y agohow about cplds are cplds okay you can get currently-manufactured cplds for under two bucks https://www.digikey.com/en/products/filter/cplds-complex-programmable-logic-devices/695?s=N4IgjCBcoLQJxVAYygFwE4FcCmAaEA9lANrggC6AvvjAEyIgqQY75GSkCsFl1I9HRgAcANgBMeQA https://www.digikey.com/en/products/filter/cplds-complex-pro... and probably nobody is going to say that an lc4032ze or an atf1502 is faster than a z80 (i mean, it's literally faster, in the same way that a 74hc04 is, but you sure aren't going to emulate a z80 on it)
- noone_youknow 3y agoThe trouble with CPLDs in my experience is the software environments and (for some at least) programming hardware. Especially for the Atmel 15xx parts, the software is windows-only, old and annoyingly crash-prone. The GALs are at least programmable from modern OSes with commodity programmers. That said, the CPLDs themselves are good chips, and I don’t think especially inappropriate for a vintage project
- kragen 3y agowell, on the plus side, the cplds are thoroughly documented, right? no struggles to reverse-engineer bitstream formats or programming waveforms. so you can write your own software to program them however you like
- unnah 3y agoI think Zilog still makes eZ80 based system-on-chip products, and eZ80 is backwards compatible with Z80. For example: https://www.digikey.com/en/products/detail/zilog/EZ80F92AZ020SG/928924 https://www.digikey.com/en/products/detail/zilog/EZ80F92AZ02...
- mischief6 3y agoas this runs cp/m, i have to wonder if the atmega itself could run cp/m faster than the z80?
- bpye 3y agoIt's been done before - but apparently the performance is pretty poor - https://spritesmods.com/?art=avrcpm https://spritesmods.com/?art=avrcpm
- kragen 3y ago
- AlexeyBrin 3y agoFor a more fun approach (if I understood your definition of fun correctly) look into RC2014 Pro, more expensive for sure, but no modern microcontroller on it.