The Retro Computer Festival is an annual event held at The Centre for Computing History Museum on the outskirts of Cambridge. It’s organised by Tony Jewell aka @HereBeDragons and this year there were 36 exhibitors. This is my second year as an exhibitor. Last year I gained a table at the last minute as Mack Wharton’s house in Jersey was badly damaged by Storm Ciarán. This year I had a few months to prepare. My …
The Zeus Assembler The Zeus Assembler was written originally for the Nascom 2 and subsequently ported to the Spectrum by Neil Mottershead and Simon Brattel in 1983. It was originally published by Crystal Computing, later by Sinclair. This was the first commercial assembler I used as a bedroom coder, originally loading it from tape, then later from Microdrive. It has a couple of features that suits developing code on target machines with limited memory. This …
The Agon Light A couple of years ago I had the priviledge of writing the initial operating system for the Agon Light, a £50 single-board computer that integrated a Zilog eZ80F92 main CPU with an ESP32 based serial graphics terminal (using FabGL). The eZ80F92 is a modern Zilog Z80 microcontroller that is fully backwards compatible with the Z80. As well as running in a traditional 8-bit mode with a 64K address space, it can run …
Is it possible to build a Spectrum 128K with no ULA? Chris Smith and Don Superfo seem to think you can. What is a ULA? A ULA (or Uncommitted Logic Array) is a specific type of gate array manufactured by Ferranti from the early 1980s. It’s a prefabricated chip with of components that can be linked during manufacture into blocks of logic gates (NAND, flip-flops, etc). A modern analogue would be a FPGA (Field Programmable Gate …
I used the Tatung Development Kit at Software Creations in Manchester from 1988 to around 1990. The company eventually replaced them with PCs. The Tatung Einstein The Tatung Einstein TC-01 is an 8-bit home computer designed for the Taiwanese company Tatung in 1984 by their British research laboratory in Bradford. It was also built in the UK. The computer is an incredibly robust and reliable machine and, unlike many of its contemporaries, it boots from …
