Oscilloscope trace of the 'fixed signals' of an Amstrad gate array being generated by an RP2350 microcontroller.

Pico Garry 2350 Part 2: FSIGS (Fixed signals)

0 commentsAmstrad CPCPico GarryUncategorizedamstradAmstrad CPCdmagate arrayPicopioRP2040RP2350

This is the second of my development logs as I work to create a replacement for the Amstrad CPC gate array based around a Raspberry Pi RP2350 microcontroller. In the previous article I divided the gate arrays input and output signals into a number of blocks depending on their function. In this article I implement ….  Read More

Designing an Intel 8008 Computer. Part 1: Power, Clocks and Signals

2 commentsCircuitsIntel 8008Uncategorized8008circuitsclocksm-cyclesProcessorst-states

The Intel 8008 was the second microprocessor, and the first 8-bit one, as well as being the first microprocessor to go on general sale. It’s an interesting and quirky beast which was constrained by bleeding edge technology and a curious edict from the Intel management. In terms of history, the 8008 was designed under contract ….  Read More

Passing Code Pointers as Data in Amstrad CPC BASIC

0 commentsAmstrad CPCAssemblerBASICUncategorizedZ80Amstrad CPCassemblerbasiccodingZ80

One of my secret coding pleasures is passing a function as a parameter to a subroutine. Most modern languages have what’s called ‘first class code’. That means that you can assign the address of a function to a variable, store it in an array, and pass it as a parameter to a function. This enables ….  Read More