TSU Meeting SUNDAY — November 17, 2024

Adam Trionfo, Joe, David, Gustavo, Johnny, Ryan Gray, Tim, Paul Anderson, Baden

Adam opened with a teardown of the Timex 2090 "command stick" — a rare 1983 Timex joystick derived from the Fairchild Channel F controller — that David had sent him for a YouTube video. The group walked through the contact ring and pivot pins, diagnosed why directions were missing (dirty contacts on the metal fingers), and traced the manufacturing lineage back to Zircon, who likely also produced the original units. David ordered a set of Zircon sticks for comparison teardowns.

David asked how to access the USB ports on his ZX Spectrum Next; Carl's note clarified that the accelerated Next's USB sockets belong to the embedded Raspberry Pi Zero and are not visible to the Next OS. On emulators, the group steered David away from CSpec toward Zesarux for emulating the Next on macOS, and recommended FUSE for ingesting real cassette WAV recordings into TAP files (FUSE remains more tolerant than Zesarux for tape captures; the EightyOne emulator handles ZX81 .p / .tzx best).

Johnny walked through Tenet networking hardware: the smaller redesigned interface board uses an 8051 microcontroller (internal EPROM) and a CPLD to replace most of the original logic, and the team will showcase a master + two slaves at Lisbon Games Week. He also showed a Sherek/Yarek Adamski FDD-3 interface clone built from discrete logic, and explained that its control-bit mapping differs from the original Timex interface, requiring a patched low-level comms routine in the ROM. Discussion ranged across FDD-3000 vs FDD-3 hardware, Zebra Systems' import of Portuguese FDDs in the late 80s (tied to a Boeing trade deal), and using Gotek drives with Flash Floppy firmware to support 256-byte sectors / double density.

Ryan reported on his TS-Pico menu/front-end project: TAP loading is solid, but DCK loading reliably crashes the Pico after several iterations — looks like a memory leak on the Pico side rather than a DCK-format problem, since the failure is in the SD-card file read. A new "noop" command was added to the Pico firmware so BASIC programs can poll the device's busy state via ON ERROR. The group agreed to ship a v1.0 of Ryan's menu with TAP support only and defer DCK to v1.1, taking the deeper debugging to Wednesday's Pico-focused meeting. A long technical aside covered the DCK header / LROS / AROS detection scheme, which chunks are ROM vs RAM, and how the 2068 boot checks signature bytes at 0000h (LROS) and 4000h (AROS). Tim announced he has ported the Boreal ZX BASIC cross-compiler to the TS2068; almost everything works, but the STR$ function crashes — Gustavo volunteered to inspect the .asm output and bisect the bad ROM call. Baden (a newer member) is working through the 2068 user manual and playing games via the TS-Pico; David warned that the "blue book" is really a Spectrum title with a Timex sticker and isn't fully accurate. Closing notes: archive.org is accepting uploads again after the hack, Paul's scan of the CX81/Nanos ZX81 fold-out reference card will be uploaded, and the next meetings (Dec 2 Monday, Dec 15 Sunday) will feature holiday-themed type-ins including Ryan's Inchworm ZX81 Christmas program.

Highlights

Teardown of the rare Timex 2090 "command stick" joystick (Channel F lineage, Zircon-built); David ordered Zircon sticks for comparison.
Johnny demoed the redesigned Tenet networking board (8051 + CPLD) and a Sherek/Adamski FDD-3 interface clone; master + two slaves heading to Lisbon Games Week.
TS-Pico menu front-end: TAP loading solid, DCK loading crashes the Pico (suspected memory leak); decision to ship v1.0 with TAP only and defer DCK.
Tim ported the Boreal ZX BASIC cross-compiler to the TS2068 — works except STR$ crashes; Gustavo took the assembly listing to find the missed ROM call.
archive.org is accepting uploads again; Paul's scan of the CX81/Nanos ZX81 fold-out reference card will go up alongside Joe's tape archiving work.

Projects discussed: TS-Pico · Library Tape Archiving Process Topics: Pico / modern interfaces (UnoDos, etc.) · Disk & floppy systems (Larken, AERCO, Oliger) · Cartridges, EPROM & dumping · Spectrum emulation & software · BASIC programming · Joysticks & controllers

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