Archive for the 'retrocomputing' Category

Amstrad CPC ROM emulation using an STM32F4 – Part 2

So in part 1 (Amstrad CPC ROM emulation using an STM32F4) the code I had for emulating a ROM (and some IO) with a cheap STM32F4 board for the Amstrad CPC 464 ran in a continuous polling loop. The code just watched  _ROMEN and _IORQ going high and low, and acted appropriately. The (sort of […]

Amstrad CPC ROM emulation using an STM32F4

UPDATE: There is a ‘part 2‘ to this article. In that I use interrupts, instead of the polling technique shown below So, in emulating a hardware ROM in real time with an STM32F4 I hooked up a cheap US$10 STM32F4 board to my Acorn Electron to act as both a sideways ROM board and a sort of […]

Emulating a hardware ROM in real time with an STM32F4

I remember reading dhole’s  Emulating a GameBoy Cartridge with an STM32F4 some time ago thinking that it had a lot of applications with respect to old computers. In that article  a STM32F4 microcontroller  ‘pretends to be a ROM chip for a gameboy’. At the start of a bus cycle, an interrupt is triggered in the […]

Using TZXDuino to play UEF tape images

TZXDuino is a cool Arduino project that is basically a standalone hardware cassette audio playback unit for old computers. You hook up an Arduino, a microSD card adapter, an I2C LCD display and 5 buttons. Load a microSD with lots of game dumps, and hook that up to the audio input of your ZX Spectrum […]

BBC Micro Model B

I recently bought a BBC Micro Model B. It sold ‘as is’ and I had no idea if it worked. The case was very yellow. It came with a  5 1/4″ drive, cassette player, several books and original versions of Elite on disk and cassette. It did not work, and ended up having a number […]

Amiga Kickstart Switcher with no switches

A while back I burnt some 27C160 EPROMs for some of my Amigas. This allows you to have 4 kickstarts in an A500 or A600. Normally you would wire up two switches to the upper address lines of the EPROM to select the 4 images. But I thought there must be some way of selecting […]

Amstrad CPC-464 and broken sound chips

So I was pretty chuffed with setting up my Frankenstrad using just a CPC-464 motherboard and a homebrew keyboard. However, as luck would have it, a few weeks later, the local auction site had a couple of real CPC-464’s for sale … so I bought one.


So I bought the motherboard out of an Amstrad CPC-464. This was like my Oric Atmos rationalisation . It’s cheaper to just buy the motherboard of some of these old computers, rather than the whole computer (especially when I add in postage from the UK to NZ). And I am more into these old computers […]

SIO2SD with an Atmega328p

So, I have a SIO2Arduino setup hooked up to my Atari 800XL as a virtual floppy drive image thingee. It works pretty well and was really easy to make; one Arduino Uno plus one Arduino SD card adapter plus a few wires. Another popular one is SIO2SD. You can buy prebuilt SIO2SDs  from Lotharek , […]

An Oric with a PS2 keyboard

So I ended up buying an Oric Atmos motherboard on I don’t have an Oric Atmos to repair. I somehow rationalised this as ‘this is cheaper than buying a whole Oric’. Of course a key problem with buying an Oric motherboard is ; “There is no keyboard”