TSU Meeting MONDAY — October 2, 2023

David, Jeff Street, Stewart Newfeld, Paul, Mitch, Gustavo, Bruno, Joe, Carl Miles, Ryan Gray, Mark

This meeting was an oral-history session with two Zebra Systems alumni: Jeff Street, who wrote the OS-64 cartridge (the 32→64 column upgrade for the TS2068, copyright 1985), and Stewart Newfeld, Zebra's founder. They walked through Zebra's catalog (banner designer, greeting cards, Z-Term 64, the Zebra Talker speech synthesizer, A-to-D / Koala-pad interface, trackball mods, the OS-64 word-processor), the 1987 catalog that signaled the end of the Timex era, Zebra's auction-buying habits (3,200 ZX81 kits bought in 1988 and slowly sold off through eBay), and how Tom G's naive bitmap-copy code prompted Jeff's epiphany about Z80 rotate/shift tricks that powered the graphics programs. Gustavo asked whether any internal Timex docs ever existed for OS-64 or the FDD-3000 (especially the Portuguese silver version with its different ROM and Motorola SCLD-replacement) — Jeff/Stuart had no surviving material, so the group pointed him back at João's Portuguese museum archive.

Mitch brought a keyboard-identification puzzle: an NMB/high-tech keyboard sold under both ByteBack and Zebra labels in SYNC magazine ads. Working from the catalog scans on archive.org the group identified it as the "Mark IV Business Keyboard" sold by E. Arthur Brown — US-made, dye-sublimated legends, with a side jack for a separate keypad — and pointed Mitch at David Leech (who bought ByteBack from Jerry Minchie in the mid-80s) and E. Arthur Brown as leads.

On the hardware-project side: Joe finally got his Westby board working on a ZX81 by lifting R30 — the German build instructions assume PAL timing, and an NTSC machine needs that resistor change. David offered to do a five-board run for anyone who wants one. Carl Miles told the full story of "Art's" TS2068-controlled CNC milling machine (sub-$100K, ~1984–85, hidden inside the cabinet behind a real keyboard, Ray Kingsley wrote the control software in Z80 machine code, programs saved to cassette) — that pile of returned/refurbished 2068s is what prompted Carl's original SCLD diagnostic cartridge. The group also discussed SCLD failure modes (rare; RAM usually goes first when the original PSU surges), the five-or-six 1500 SCLD iterations visible in Timex's NCR-process documents, and Larry Kenny's parallel attempt to use a 2068 as a CAD/CAM engine via HiSoft Pascal (abandoned — Z80 too slow).

David gave a status update on the TS-Pico SD-card cartridge: circuit boards are in manufacturing, delivery targeted for November. The new revision uses a Raspberry Pi Pico, a 512K flash chip carrying Gustavo's custom OS plus room for ~8 ROM images (Spectrum ROM included, so the cartridge works in Spectrum mode too), and 512K RAM mappable into the DOCK bank as a RAMdisk. The board holds reset low while the Pico boots, then releases — similar to how Oliger works, but slower-power-on. Jeff Burrell's slot-board lets it sit in a back-of-machine expansion box (3D-printable case in progress) or take an edge connector directly. Separately, Joe is iterating a 3D-printed cartridge shell (originally a Portuguese-2068-sized design that Joe is shrinking to fit US 2068 cartridge slots), and David's matching board adds a rotary image-select switch, a write-enable switch, and a larger flash chip holding eight 16K images. The meeting closed with Carl pitching a community effort to 3D-print a faithful TS-2060 Bus Expansion Unit shell from the surviving CES photos — the long-rumored Timex peripheral box — as a physical home for future 2068 expansion hardware. David has a Shapeways contact (a model-railroad-parts designer) who could do the CAD.

Highlights

Oral-history interview with Jeff Street (OS-64 cartridge author) and Stewart Newfeld (Zebra Systems founder)
Mitch's mystery ByteBack/Zebra keyboard identified as the NMB/high-tech "Mark IV" sold by E. Arthur Brown
Joe's Westby board for the ZX81 worked once R30 was lifted — German design assumes PAL timing, NTSC needs the mod
Carl recounted Art's TS2068-controlled CNC milling machine (Ray Kingsley wrote the Z80 control software, ~1984–85), which is also why Carl wrote the original 2068 SCLD diagnostic cartridge
TS-Pico SD-card cartridge boards in manufacturing, November delivery — Gustavo's custom OS, 512K flash with Spectrum-mode ROM, 512K RAM mappable to DOCK bank

Projects discussed: TS-Pico Topics: TS2068 / TC2068 · Cartridges, EPROM & dumping · Pico / modern interfaces (UnoDos, etc.) · Hardware projects & new boards · TS1000 / ZX81 / TS1500 · Disk & floppy systems (Larken, AERCO, Oliger)

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