Here are upgrade instructions for your ZX Diag Cart interface (Steve Smith’s design). These might also work on the ZX Diag Cart from Brendan Alford. Current version: 0.37 Check your version by holding down Symbol Shift when booting up the ZX Diag Cart. All the new features for every release are found here: https://github.com/brendanalford/zx-diagnostics/releases For … Continue reading ZX Diag Cart upgrade instructions