Showing posts with label workslate. Show all posts
Showing posts with label workslate. Show all posts

Saturday, January 18, 2025

The "35-cent" Commodore 64 softmodem

Rockwell famously used 6502-based cores in modems for many years, but that doesn't mean other 6502s couldn't be used. If only there were a way to connect a Commodore 64's audio output directly to an RJ-11 plug ...
Of the many interesting posts from Usenet's more golden days, one of my favourites was John Iannetta's "35-cent modem," where the SID chip provides one-way data modulation to a receiving modem connected via the C64's sound output. While I remember him posting it back in 1998, I never actually tried it at the time.

Wouldn't you know it, but it came to mind the other day when I was looking at a recent haul of Convergent WorkSlate stuff I've got to catalogue. Officially the WorkSlate's only means of telecommunications is its 300 baud internal modem. While we have a 9600bps way of wiring up a Workslate to a modern computer, it's always nice to have a simpler alternative, and I figured this would be a great challenge to see if John's old program could let my Commodore SX-64 talk to my WorkSlate. Spoiler alert: it works!

Tuesday, September 3, 2024

Programming the Convergent WorkSlate's spreadsheet microcassette future

In this particular future, we will all use handheld spreadsheets stored on microcassettes, talking to each other via speakerphone, and probably listening to Devo and New Order a lot. (Though that part isn't too different from my actual present.)
It's been awhile since we've had an entry for reasons I'll talk about later, and this entry is a doozy. Since we recently just spent a couple articles on a computer whose manufacturer insisted it was mostly a word processor, it only seems fitting to spend some time with a computer whose very designer insisted it was mostly a spreadsheet.

That's the 1983 Convergent WorkSlate, a one-of-a-kind handheld system from some misty alternate history where VisiCalc ruled the earth. Indeed, even the "software" packages Convergent shipped for it — on microcassette, which could store voice memos and data — were nothing more than cells and formulas in a worksheet. The built-in modem let you exchange data with other Workslates (or even speak over the phone to their users), and it came with a calculator desk accessory and a rudimentary terminal program, but apart from those creature comforts its built-in spreadsheet was the sole centre of your universe. And, unlike IAI and the Canon Cat, I've yet to find any backdoor (secret or otherwise) to enable anything else.

That means anything you want to program has to be somehow encoded in a spreadsheet too. Unfortunately, when it comes to actually programming the device it turns out the worst thing a spreadsheet on an 8-bit CPU can be is Turing-complete (so it's not), and it has several obnoxious bugs to boot. But that doesn't mean we can't make it do more than balance an expense account. Along the way we'll examine the hardware, wire into its peripheral bus, figure out how to exchange data with today's future, create a simple game, draw rudimentary graphics and (with some help) even put it on the Internet with its very own Gopher client — after we tell of the WorkSlate's brief and sorrowful commercial existence, as this blog always must.