TSU Meeting SUNDAY — September 15, 2024
David, Ingo Truppel, Michael Truppel, Johan Koelman, Larry Lorenson, Joe, Adam Trionfo, Ryan Gray, Paul DeMelto, Gustavo
Ingo Truppel (with his brother Michael) presented the KiloZ, a modernized ZX81 they have been building for over a year. It packs a hot-swappable mechanical keyboard, a Traco switching power supply, a 32K RAM expansion split across two 16K banks, the CX8 CCB composite-video mod, and a ZX-Wespi Wi-Fi file server with VGA output, all inside a 3D-printed case modeled on the ZX81. Ingo demoed loading and saving P-files over Wi-Fi from the Wespi's onboard web server and showed clean VGA capture into Zoom. He confirmed VGA output requires the ZX81 be switched to 50 Hz (lift R30); without that change he had been stuck for weeks. Michael walked through plans to produce the case as a silicone-mold resin cast for higher-volume production, and the brothers floated a future full-size "MegaZ" with an Apple-II-style expansion plane.
Johan Koelman shared news from the Wespi's developer: because the loader code is so tightly written (~949 bytes), the Wespi should be usable on a stock 1K ZX81, not just 16K-expanded machines — which would open the device up to a much wider audience. Larry Lorenson added practical tips (use graphics-shift-9 for lowercase Wi-Fi passwords; press X to refresh the on-screen file listing after uploads).
David gave a TS-Pico status update: Ricardo Calcagno has pushed substantial updates, with Adam Trionfo, Ryan Gray, and François beta-testing. A version mismatch in MicroPython between Ricardo's build and the testers' was tracked down; the goal is a drop-in SD-card update package that the Pico auto-applies. Gustavo joined to explain the design of the TPI extension: existing tape commands (LOAD, SAVE, MERGE) work unmodified — you only prefix new operations with SAVE TPI: — but the implementation depends on free space in the 2068's HOME and XROM areas, which is why a direct Spectrum port isn't feasible. Future work includes routing LPRINT/LLIST to .txt files and SCREEN$ to BMPs. Johan compared loading speed with his earlier interface (~7 s for a 48K image) and noted the SD-card read path is usually the bottleneck.
The group also discussed FujiNet for Sinclair (David will email Michael Carter for an update), the state of community tape archiving — Joe demoed the mvindalzx81.tape-reader GitHub tool for hand-editing noisy ZX81 tape captures bit by bit, contrasting it with the EightyOne emulator's WAV import — and longer-term plans to use a shared Google Docs space for collaborative preservation: keyboard tutorials for newcomers, Carl's repair tips, ROM-bug patches (the DELETE-on-colon bug, the XROM addressing flaw), and a TS2020 / MiniSet 9 belt-replacement guide. Adam suggested a recurring "origin stories" segment; Ryan reported an off-by-one column bug in the recently shared 20-line Galaxian BASIC listing (line 200 should print at G−1). The next meeting was set for Monday, October 7, 9 PM Eastern.
Highlights
- Ingo Truppel demoed the KiloZ: 3D-printed ZX81 with mechanical keyboard, 32K RAM, ZX-Wespi Wi-Fi storage, and clean VGA output.
- Johan Koelman reported the ZX-Wespi loader is small enough (~949 bytes) to run on a stock 1K ZX81, not just 16K-expanded machines.
- TS-Pico beta testing progressing; goal is an SD-card auto-update package after resolving a MicroPython version mismatch.
- Gustavo explained the TPI extension reuses free 2068 HOME/XROM space, which is why it cannot be ported directly to the Spectrum ROM.
- Joe demoed the mvindalzx81 tape-reader for hand-editing noisy ZX81 tape captures bit-by-bit before exporting to TZX.
Projects discussed: TS-Pico · ZX-Wespi / Wespi-Nano · Library Tape Archiving Process Topics: Hardware projects & new boards · Pico / modern interfaces (UnoDos, etc.) · TS1000 / ZX81 / TS1500 · Video upgrades (composite, RGB, HDMI) · Tape & library archiving (TAP/TZX) · Tape, cassette & loading
Summary generated from the meeting recording; the full transcript is kept in the group's private archive.