Retrocomputing for $4 with a Z80

Sure, you’d like to get in on all the retrocomputing action you read about on Hackaday. But that takes a lot of money to buy vintage hardware, right? Sure, you can build your own, but who has time for a big major project? [Just4Fun] has a Hackaday.io project that disproves those two myths and gives you no more excuses. His retrocomputer? A 4MHz Z80 that can run BASIC with 64K of RAM, all built on a breadboard with 4 ICs. The cost? About $4.

Of course, that’s with some power shopping on eBay and assuming you have the usual stuff like breadboards, wire, small components, and a power supply. While it will gall the anti-Arduino crowd, [Just4Fun] uses an Arduino (well, an ATmega32A with the Arduino bootloader) to stand in for a host of Z80 peripheral devices. You can see a video of the device below, and there are more on the Hackaday.io project page.

The ATMega serves as a clock and reset generator. It also is the computer’s EPROM. There is a separate RAM chip, but half of it isn’t used (we smell a bank switching mod here). You do need the CMOS Z80 chip to play nice with the other modern chips like the ATMega.

This is a great retro project. We can’t help but notice the IC pin labels on the chips which is a nice touch, along with the labels on switches and LEDs.

[Just4Fun] has done this kind of thing more than once. If you are wondering how many chips the ATmega saves, you might have a look at this build.