Oli's old stuff

Tinkering with retro and electronics

Feb 6, 2021 - 7 minute read - sinclair electronics retro hardware zx spectrum zxsprite

ZX-Sprite Hardware Prototype - Part 2

ZX-Sprite This is a short series about exploring ZX-Sprite, a fantasy hardware add-on for the ZX Spectrum that aims to bring Spectrum Next style sprites to the 48K and 128K systems. The series ZX-Sprite Introduction ZX-Sprite Prototype - Address decoding ZX-Sprite Prototype - Baremetal Pi GPIO (this post) Going Baremetal Last time we went over how to use a GAL22v10 to decode the 3 ports we need to control the sprite system.

Feb 5, 2021 - 9 minute read - sinclair electronics retro hardware zx spectrum zxsprite

ZX-Sprite Hardware Prototype - Part 1

ZX-Sprite This is a short series about exploring ZX-Sprite, a fantasy hardware add-on for the ZX Spectrum that aims to bring Spectrum Next style sprites to the 48K and 128K systems. The series ZX-Sprite Introduction ZX-Sprite Prototype - Address decoding (this post) ZX-Sprite Prototype - Baremetal Pi GPIO Introduction The last post introduced the idea of ZX-Sprite, a port of the Spectrum Next’s sprite system to the ZX Spectrum hardware.

Feb 5, 2021 - 9 minute read - sinclair electronics retro hardware zx spectrum zxsprite

ZX-Sprite Introduction

The series ZX-Sprite Introduction (this post) ZX-Sprite Prototype - Address decoding ZX-Sprite Prototype - Baremetal Pi GPIO ZX-Sprite: An Introduction Towards the backend of 2020 I started working on a Spectrum Next game; the game uses a couple of the cool features of Next - tilemaps and sprites. As a bit of fun, I started to adapt my emulator to support both of these; mostly because I’ve got into a bit of a nice workflow with this emulator; one that I can’t quite get from CSpect.

Sep 20, 2020 - 8 minute read - sinclair electronics retro hardware zx81

ZX81 hardware hacking - Homebrew ZX8-CCB

ZX81 Hardare Hacking - Homebrew ZX8-CCB In my last post I talked about the problems associated with the video signal that the ZX81 outputs. There are various mods that can correct this, with one of the leading ones being the PokeMon ZX8-CCB. In this post I’ll explore a homebrew hack that aims to recreate the ZX8-CCB for fun and educational purposes. DISCLAIMER This is not endorsed or associated with the original ZX8-CCB project in any way.

Sep 19, 2020 - 8 minute read - sinclair electronics retro hardware zx81

ZX81 Video Conditioning Mods

ZX81 Video Conditioning Mods The ZX81 is notorious for outputting an RF signal that modern TVs struggle with. This is a post that explores the video signal from the ZX81 and discusses a few of the mods for improving it. ZX81 Composite Mods Modern TVs have issues with the ZX81 RF signal, and most common solution is for people to modify their ZX81 for composite video out. Knowing nothing about the subject, I rushed out and bought a kit from tfw8bit.

Sep 6, 2020 - 8 minute read - spectrum electronics retro hardware 4116 ram

ZX Spectrum 4116 RAM Replacement Board - Part 2

Building a ZX Spectrum Lower Ram Replacement Board - Part 2 In my last post I talked about the broadboard prototypes of my attempt to build a Lower RAM replacement for the ZX Spectrum. It was encouraging to see that something could work on a breadboard, even if it was glitchy. The long wires and extra capacitance would cause a lot of noise for something that needed to be accessed as frequently as RAM.