Table of Contents
About 40 years ago I built a BASIC extension cartridge for the VIC-20. Recently I decided to recreate it, but this time doing it properly.
From Single-Purpose to Universal
The original was a straightforward single-configuration board. This time around, rather than designing one PCB per memory configuration, I went with a universal cartridge board that covers the common configurations:
- 8K — BLK 5 only
- 16K — BLK 3 and BLK 5
- 32K — BLK 1, 2, 3, and BLK 5
This means one board design handles everything from a simple 8K cartridge up to a full 32K expansion.
NOR Flash Support
The board also supports a 32K NOR flash chip as an alternative to ROM. This makes reprogramming straightforward — no need to pull chips or dig out a UV eraser. Just reflash in place and go.
Optional 3K RAM Expansion
For those wanting to mimic a Super Expander, the board includes an optional 3K RAM expansion covering $0400–$0FFF. This fills the otherwise unused memory area below the default BASIC RAM start, giving you that extra bit of space the Super Expander was known for.
Summary
One board, multiple configurations, and modern flash support — a simple but flexible design that covers most VIC-20 cartridge use cases while staying true to the original idea from four decades ago.
It also fits nicely in the new universal mechanics for the GCart series.