TSU Meeting MONDAY — November 3, 2025

David, Adam Trionfo, Jeff Fetta, Jonathan, Carl Miles, Gustavo, Ryan Gray, Robert Fischer, Michael

David opened with a seasonally-appropriate type-in: a low-res "Turkey" drawing program from Family Computing (Nov 1983) for the TS1000, run in the EightyOne emulator. Adam suggested following up at a future meeting by playing 'Santa's Dilemma' (ZX Computing, Dec 1986) as a group, since it's already archived on the site. David then announced his next preservation video: a deep dive on Tom Woods's Profile database — the original 1000 version, Profile 2068, the cartridge edition that absorbed most community add-ons, and Profile Plus Five — drawing on prior Zoom recordings of Tom Woods and Robert Fischer plus a fresh one-on-one with Bob about his 'Extensions' newsletter modifications.

Jeff Fetta, returning after several years, walked through two projects he showed at VCF Midwest: a CompactFlash adapter for the ZX81/TS1000 (CF in 8-bit mode behaving as an IDE-like device, 64K RAM, the 'Shoulders of Giants' ROM, custom load/save routines and a 1.5K FAT driver so LOAD/SAVE work directly against P-files), and a from-Wilf-Rigter ZonX sound clone (his first KiCad board). He then demoed his in-progress engineering emulator for the ZX81 in SDL — register/memory inspector, breakpoints, system-variable view, live display-file dump — and explained that he's modeling the ULA at the shift-register level so he can finally get pseudo-hi-res titles like Rock Crush running. His older TS2068 engineering emulator suffered SDL bit-rot and he's reviving it. Discussion branched into Shoulders-of-Giants ROM internals, the TS1500's SCLD (RAM-remap and channel switching done in hardware, only the cartridge probe changes in ROM), and Charles Ingley's VLA81 FPGA ULA replacement — no TS1500 variant yet exists, which the group flagged as a wanted item. Gustavo pointed back to the Chuao/David YouTube series where the NCR SCLD schematic was shown.

Jonathan, a new member in Annapolis MD via New Zealand, introduced himself (ZX81 at school age 11, large Sinclair collection, restoring ZX81 titles) and asked for TS1500 repair pointers — Jeff and Carl walked him through scoping the ULA video pin and ruling out the membrane. Carl Miles led an extended discussion of the ZX-Wespi: it's open source but written for 50Hz PAL machines, so US 1000s need a hardware mod to drop to 50Hz. He's hoping someone will dig into the ESP32 C code to add 60Hz support (ideally auto-detect from sync pulses) and round-trip saving, neither of which Wespi currently does. That dovetailed into David showing the 'OpenSpand' — an open-source ZXPand clone using the Pi 2350 XL-Stamp, SD card and DAC, currently being developed on Sinclair ZX World forums; David has volunteered to build and ship the hardware for US buyers once it's ready.

David is hunting for issue #1 of Timex's 'Ramblings' newsletter (one's on eBay for $20) and asked anyone with a copy to surface it; he also showed a Norwood XLP cassette deck — externally a near-twin of the 2020 but with half-speed playback and a stereo-head selector switch, likely a dictation-and-computer hybrid. Carl closed with two hardware demos: a nearly-populated 'Interface Zero' PCB that lets a Spectrum Interface 1 (with twister board) talk to a TS2068, with Spectrum ROM, diagnostic ROM, both IF1 ROM revisions in flash, and a daughterboard for RS-232 / dual network ports; and an internal Wespi-mount board that drops in where the TS1000/ZX81 RF modulator sits, exposing VGA + composite via a mini-DIN-8 on the original TV-out cutout (US-case layout, ESP32 on the underside). Carl also mentioned in passing his 1068 (enhanced TS1000) build and a 1510-style ROM replacement cartridge; full external ROM still needs some ULA logic pulled out, which Jeff is working through in the emulator.

Highlights

Jeff Fetta demoed his ZX81 CompactFlash adapter (8-bit IDE-mode CF, 64K RAM, Shoulders-of-Giants ROM, FAT driver hooking LOAD/SAVE to P-files) and a Wilf-Rigter-based ZonX sound clone shown at VCF Midwest
Jeff is building an SDL-based engineering emulator for the ZX81 (live registers, breakpoints, system variables, ULA-level shift-register modeling) targeting pseudo-hi-res support for Rock Crush; older TS2068 emulator being revived from SDL bit-rot
Carl Miles asked for help porting the ZX-Wespi ESP32 firmware from 50Hz-only to auto-detecting 60Hz, and adding save support — and showed a drop-in modulator-replacement board exposing VGA + composite via mini-DIN-8 for US cases
David announced a forthcoming video on Tom Woods's Profile database lineage (1000 / 2068 / cartridge edition / Profile Plus Five) including Robert Fischer's Extensions newsletter modifications
OpenSpand — an open-source ZXPand clone on the Pi 2350 XL-Stamp with SD + DAC + audio + joystick — is in development on Sinclair ZX World; David volunteered to build US units when it's ready

Projects discussed: ZX-Wespi / Wespi-Nano · TS1510 Cartridge Interface Clone · "1068" — Enhanced TS1000 Topics: TS1000 / ZX81 / TS1500 · Pico / modern interfaces (UnoDos, etc.) · Hardware projects & new boards · TS2068 / TC2068 · Video upgrades (composite, RGB, HDMI) · Utilities & applications

Summary generated from the meeting recording; the full transcript is kept in the group's private archive.