Timex Sinclair User Group Meeting — February 6, 2023

David, Adam Trionfo, Paul Holmgren, Dave Scott, Stewart Newfeld, Ryan Gray, Keith, Larry, Gustavo, Tim Swenson

The meeting opened with two newcomer introductions. Paul Holmgren — co-owner of Mechanical Affinity with Frank Davis, the Indiana mail-order outfit and TS2068 Disk Update newsletter that hung on until roughly 1991/92, and co-author with Willie Jones of the Indiana Sinclair/Timex BBS software — joined for the first time. Paul shared two pieces of Timex trivia: a US Supreme Court justice (he believes Souter) was a TS2068 customer in the late 80s/early 90s, and any order shipped to South America had to be doubled because customs officers would keep one of every item. Dave Scott (Glasgow → Bellingham, WA), found the group via TJ Ferrari's Patreon, came up through the Spectrum and ZX Next side and is looking for a 2068; that detour pulled in a long aside on the Enterprise 64, the Hungarian Z80 machine with cartridge-swappable Spectrum-emulating ROM. David also announced that Danny Ross, former VP of Timex Computer Corporation, has agreed to present on Sunday Feb 19, with George Grimm (Timex software manager who approved third-party titles) also being lined up; the Ross talk will be streamed to YouTube, and a Google Doc was opened for questions to coalesce in advance.

Stuart walked through the ZX-Westby / ZX-Wespi project — an ESP32 acting as a web server that serves p-files to a ZX81 — for which he has designed a custom PCB. The board uses an ESP32 dev-kit module (skipping a bare ESP at the chip level), brings out optional jacks for EAR/MIC instead of soldering to internal points, has an option for the 320×240 LCD or VGA/RGB output, and uses 0805 surface-mount parts as his first proper SMT exercise. The board is wired and the display works under the Arduino IDE example sketch, but the Espressif flashing tool isn't producing a running image — Larry pointed out the four check-boxes in Espressif's flasher that have to be ticked. Stuart plans to push the design to GitHub as open source once it's verified, and offered to mail a board to anyone wanting to try it. That spun off into PCB-manufacturing chat (JLCPCB, five boards for two dollars, China COVID delays), Stuart's other in-progress boards (a tactile ZX81-keyboard-to-USB adapter, a revision of Tim Horner's Arduino-shield 2040-printer interface), and a Digilent Basys 3 FPGA board he just received — leading to a discussion of using an FPGA as glue logic to drive HDMI/VGA from the TS bus digitally, MiSTer cores for Spectrum/Enterprise, and the wish for a DSP-style FPGA project that could clean up dropouts in old Timex tape recordings.

Ryan Gray then demoed two ZX81 utilities he posted to GitHub. The first is a p-file-to-text decoder with two output modes — readable Unicode and zmake-basic-compatible escape sequences — that round-trips machine code embedded in REM statements. The second is a ZX81-to-Spectrum BASIC converter that follows his earlier write-up of the differences: gray block graphics are turned into UDGs A–F (with an auto-inserted subroutine that programs them), UNPLOT becomes PLOT INVERSE 1, plot coordinates are multiplied by four, SCROLL is emulated by poking the line-count system variable, POKEs are commented out into REMs, PEEKs are converted to INs with warnings, and SAVE-with-inverse-last-character is rewritten to SAVE-with-LINE. He also showed printable character-set cheat sheets for both the 2068 and ZX81, with hex/decimal/binary cross-references and shift-key columns, that he tucks under his keyboard. Compilation works under GCC on Linux/Mac (Xcode command-line tools), with Windows builds via WSL or MS Build Tools to come.

Keith showed his AERCO floppy interface stack: an Amdek dual 3-inch drive (single-sided, ~195K per side, originally a generic Shugart-compatible unit he re-cabled), the AERCO dual serial port board behind it, and a Larken cartridge-plug parallel port — letting him use Larken and AERCO peripherals on the same machine. Paul Holmgren and Willie's BBS code came up in the same arc: Paul rewrote TinyBoard with control-character filtering done in Z80 so junk never reached the BASIC interpreter, logged connection attempts to a 2040 printer, and ran it with the Oliger disk system swapping message bases — they had also run it on an A&J stringy-floppy (short loops only, for access time). Other threads: Jack Dellaheny supplied Paul with a 32K Spectrum+Timex ROM with pull-ups and a battery-backed real-time clock; the carrying case with an Oric red-and-black keyboard hollowed into it (the same one Keith has, and which Paul brought to the 1987 Southern show); and reminiscences about Mark Fendrick's "Sinclair Survival" column in Computer Shopper and "Across the Pond" in ZX Computing, plus Stan Kelly-Bootle, reputed to hold the first CS degree in the UK.

Highlights

Paul Holmgren (Mechanical Affinity / TS2068 Disk Update / Indiana Sinclair-Timex BBS co-author) joined the group for the first time
Stuart's PCB for the ZX-Westby/Wespi ESP32 web-server-for-ZX81 project is built but won't flash — Larry identified the four un-ticked check-boxes in Espressif's flasher tool
Ryan Gray released two ZX81 utilities on GitHub: a p-file → text/zmake-basic decoder and a ZX81 → Spectrum BASIC converter (UDG-substituted gray graphics, UNPLOT→PLOT INVERSE 1, SCROLL via system-variable poke, etc.)
Keith showed his AERCO floppy stack — Amdek dual 3-inch drive, AERCO dual serial card, and a Larken parallel cartridge — running side by side; Paul described running his TinyBoard-derived BBS over the Oliger system (and briefly over A&J stringy floppy)
Danny Ross, former VP of Timex Computer Corporation, confirmed for Sunday Feb 19 at 2pm Eastern; questions go in a shared Google Doc and the session will be streamed to YouTube

Projects discussed: ZX-Wespi / Wespi-Nano Topics: Hardware projects & new boards · TS1000 / ZX81 / TS1500 · Pico / modern interfaces (UnoDos, etc.) · Disk & floppy systems (Larken, AERCO, Oliger) · BASIC programming · Utilities & applications

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