Timex Sinclair User Group Meeting — April 4, 2022

David Anderson, Tim Swenson, David Spinnett, Willie, Carl Miles, Jay, Ingo, Adam Trionfo, Keith, Neil Cohen

Tim Swenson was the guest and walked the group through forty years of Sinclair newsletter publishing. He started writing for Timelines with the Bay Area QL/Timex user groups in the mid-80s, then took over the CATS newsletter (Capitol Area Timex Sinclair user group) while stationed at the Pentagon, ran the QL Hackers Journal for ten years as a half-sheet print/email zine, and currently publishes SMSQ Zine (QL) and ZXZine (ZX81/2068) using Scribus and all-open-source tools. Tim also recapped his hardware path from a CX-81 (1981) to a TS1000, a TS2068 that died at six months (SCLD failure), and a 1986 QL he kept as his main system into 2000 — Gold Card, ROM disk, EDs, the Sinclair QL Vision monitor, and a QL emulator (SMSQ/E, QPC2, SQLX) workflow today. David Spinnett dropped in to share that he and a friend are writing new hi-res Z80 assembly for the TS1000 (a Donkey Kong remake), have built a universal 3D-printed Sinclair power supply, and bought Marcel Kilgus's VGA adapter for the QL.

On the hardware side, David relayed an update from Neil Cohen in Florida: Neil's Larken RAM disk had its connector soldered on backwards, and a friend is reverse-engineering it with the goal of producing new boards with a USB-rechargeable battery-backup circuit. Willie described his custom build of Profile 2068, converted from cassette to the JLO disk system so users could swap floppies for much larger address-book databases — relevant because Bill Jones's TS2068 Update newsletter had estimated ~700 disk systems in the field (≈400 on one platform). That led into reminiscence about Larry Kenney (Larken, now in Ontario making CNC machines after running his 2068-based controller in compiled Pascal) and John Oliger, plus the Fred Nachbaur / John Oliger TI-9918 color video add-on for the TS1000.

Show-and-tell ran long. David demoed the ZX99 "data-set" (two-tape cassette controller for the TS1000, needing a 10-ohm resistor on the remote line), the Sinclair beeper add-on, the joke "ROM/RUM" keycap-sticker set, and a TI-99-style speech box he had in the garage. Ingo demoed his hand-built full-size mechanical keyboard for the ZX81/TS1000: Gateron switches on a laser-cut black acrylic plate, hand-wired with ribbon, and custom Inkscape water-transfer decals — the first run peeled, but a model-railroad decal solvent plus clear-coat made the second run stick. He plans a v2 with a microcontroller for a 60% layout and will blog the build. That dovetailed into a long discussion of building a PS/2 or USB keyboard adapter for the Timex machines (FPGA versions exist; a Pi Pico is the obvious modern part) — David has redrawn Jack Doheny's 1996 schematic (two 2764 EPROMs + 74HC365) and ordered cartridge-slot boards. Carl noted the ZX81 hangs the matrix off the address/data bus while the 2068 routes it through the SCLD, which changes where the adapter has to tap in. Sourcing cartridge-slot keying plastics from Digi-Key/Mouser was flagged as overpriced ("30% unobtainium"); the workshop alternatives are soldering two pins or cutting down a larger connector on a bandsaw.

Administrative wrap-up: David wants to organize community tape archiving as a recurring effort — Jay has commercial tapes, Tim has more, Adam has the rig, and Paul Backer was named as the audio-cleanup specialist (with surprising results from platinum audio cabling). The third-Sunday meeting was moved to the fourth Sunday of April to avoid Easter. Upcoming guests David has been recruiting include Tom Woods (Profile databases, Syncware News, the 32K RAM cartridge with Tom Bent), Alder Salt (VOTEM analog-to-digital interface for the TS1000 — reportedly used on a shuttle project), Lon Hildreth, Dave Ornstein (early Sinclair insider who sold ZX80 schematics), Nazir Pashtun (Chicago group, Twister adapter), Bob Swoger (Larken/Oliger menu front-end), and Bruno for a Sunday slot.

Highlights

Tim Swenson recapped 40 years of Sinclair newsletter publishing — Timelines, CATS, the QL Hackers Journal, and his current SMSQ Zine and ZXZine
Neil Cohen's Larken RAM disk is being reverse-engineered for a community repro board with USB-rechargeable battery backup
Willie described his custom Profile 2068 ported from cassette to the JLO disk system
Ingo demoed his hand-built full-size mechanical keyboard for the ZX81/TS1000 with custom Inkscape water-transfer keycap decals
Long thread on a PC-keyboard-to-Timex adapter — David has redrawn Jack Doheny's 1996 schematic and ordered cartridge-slot boards

Projects discussed: TS1510 Cartridge Interface Clone · Library Tape Archiving Process Topics: Newsletters & documentation · TS1000 / ZX81 / TS1500 · Hardware projects & new boards · Disk & floppy systems (Larken, AERCO, Oliger) · Cartridges, EPROM & dumping · Tape & library archiving (TAP/TZX)

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