TSU Meeting SUNDAY — June 23, 2024

David, Joe, Tim, Gustavo, Ryan Gray, Larry Lorenson, Mike, Jack, Mowgli, Paul Holmgren, Keith Watson

Joe opened with a demo of the SPO 256 speech synthesizer (the UK William Stewart Systems unit, paired with a "Big Ears" speech-recognition module) saying "Welcome to the Timex Sinclair online computer group." He then reported that he had finished his redesigned cartridge for Carl Miles's TS1510 reconstruction: drawn in EasyEDA with a surface-mount baseboard but a through-hole socketed EPROM (so it can be reprogrammed in a TL866) wired for 32K/48K images at the standard 8–16K window with image-select switches. A matching 3D-printed case in silver plastic, similar to the original 1510 cartridge, is next; he has sent the design to Carl and the group for review before ordering PCBs.

A long discussion of why the group still bothers with the TS1000/ZX81 (challenge, nostalgia, fitting code into a tiny machine) led to Ryan Gray's thought experiment of a 16K ROM for the 1000 that would bring Spectrum-style BASIC down to the smaller machine — touching on the John Oliger / Fred Nadelbauer TMS9918 video board, Wilf Rigter's ZX97, and how much of the Spectrum's improvement was really just the extra 8K of ROM. Members showed off period cassette recorders (Radio Shack CCR-81/82, a GE "computer" cassette unit, cheap modern Chinese decks with internal speed pots) and traded tips on calibrating motor speed against a 1 kHz reference tone. Larry Lorenson described trying to replicate Carl's circuitry on a hand-wired board and a strange failure mode where locking the ZIF socket — empty or populated — freezes the machine.

New attendee Mowgli introduced himself as the author of Sector 2068, the AERCO disk sector editor he wrote at 18 on his 2068 and sold through Rod Gowan (about 80 copies at $15, $3 to him). He still has his AERCO drives, disks, and paperwork, and his manual's appendix documenting the AERCO disk anatomy is exactly what David needed to extend his Python disk-imaging/extraction tooling (which already handles Larken and Oliger images via Greaseweazle, producing TAP files) to AERCO. Gustavo (Argentina), also an AERCO owner upgraded to 256K running RPM/CP/M, noted that an Argentine company cloned the AERCO as the FD68 and even adapted the +D for the 2068. Keith Watson revealed he bought the AERCO ROM source for $20 back then and has his own modified versions up to 10.7. David confirmed Jerry Chamkis of AERCO passed away in 2021 (he had moved on to building microphone preamps for Grateful Dead tapers).

On archiving, David walked through his preferred tape-recovery workflow — load a wobbly cassette into a real TS1000, save the cleaner output back out as a WAV via Audacity, and let the EightyOne emulator's waveform tools convert it to P/TZX — and discussed using a compander (e.g. the 570 chip) for tapes with bad dropout. He has roughly 600–700 programs archived so far. Larkin disks from Bob Swoger's collection are loaded with Larken-specific BASIC commands (RAND USR 100 etc.) that reset a stock 2068; Ryan and David agreed to write a filter that strips/translates those so the programs run on plain machines, and Gustavo proposed a broader conversion tool from disk images to standard TAP. The TS-Pico's TPI command set (Gustavo's public-domain OS work on Ricardo Calcagno's hardware) was contrasted with the closed ESXDOS on DivIDE/DivMMC. Housekeeping: the Wednesday-evening slot is becoming a hardware SIG; next general meeting is Monday July 1 at 9 PM Eastern (shifted because Father's Day displaced the usual third-Sunday slot).

Highlights

Joe finished a redesigned TS1510 reconstruction cartridge in EasyEDA — SMT baseboard, socketed EPROM, original-style 3D-printed case to follow
Mowgli, author of the AERCO sector editor Sector 2068, joined the group; his manual's AERCO disk-format appendix unlocks David's TAP-extraction tooling for AERCO images
Gustavo confirmed an Argentine company cloned the AERCO as the FD68 and even adapted the +D for the 2068; Keith has private AERCO ROM mods up to v10.7
Ryan and David agreed to write a filter that strips Larken-specific BASIC commands from Bob Swoger's disk collection so the programs run on stock 2068s
Wednesdays are becoming a hardware SIG; next general meeting is Monday July 1, 9 PM Eastern (Father's Day shifted the usual third-Sunday slot)

Projects discussed: TS1510 Cartridge Interface Clone · TS-Pico · Library Tape Archiving Process · "1068" — Enhanced TS1000 Topics: TS1510 cartridge interface · Disk & floppy systems (Larken, AERCO, Oliger) · Tape & library archiving (TAP/TZX) · TS1000 / ZX81 / TS1500 · Cartridges, EPROM & dumping · Tape, cassette & loading

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