Saturday, March 30, 2024

Refurb weekend: Data General/One (and the worst LCD in the world)

I mentioned earlier that while I prefer specializing in non-x86 laptops, that doesn't mean I don't collect interesting or unusual x86 laptops, like the Brother GeoBook NB-60 (I finally tracked down a mostly working NB-80C, the top of the line model, which will be the subject of a future restoration). However, this one is a unit I've had since about 1998 when they were getting rid of it at the University I worked for, and in many ways a landmark PC laptop since it was the first battery-capable system with a full 80x25 or CGA 640x200 LCD — though with a notorious deficiency: more on that shortly — and also came with a terminal and text editor in ROM. This is the 1984 Data General/One.
I suspect it was primarily used to dial into the campus network using the built-in modem and ROM terminal emulator, at least until better alternatives became available, and then ended up forgotten somewhere until they were cleaning things out and asked me if I wanted it. (Yes, I was retro even before retro.) It came with its bag, power supply and modem cable, and of course I said yes. It wasn't pristine, though: the floppy disk eject buttons wouldn't stay on anymore, it couldn't remember its hardware configuration, and the main drive had issues with nearly full disks. And then there was that infamous LCD.

Ah, what the heck. I finally got a round tuit. That makes it time for ... another Refurb Weekend.

Monday, March 18, 2024

After 41 years, my first assembly program on my first computer, the Tomy Tutor

We got it in 1983, I think, so it only took me about 41 years to get around to it. This Tomy Tutor isn't a replacement system I secondarily acquired, nor is it a Ship of Theseus Frankenstein rebuild. This is my actual first computer, in its original case, on its original components, with the Federated Group sticker still on the original box. And it still works.
Now, why so long? Well, for one thing, it was only supposed to be a training wheels computer because a full Commodore 64 system would have cost too much, but my folks wanted to see whether we'd take to a home computer and His High Holy Munificence Fred R. Rated was blowing these babies out for a song by then. The receipt has long since disappeared, though $99 sounds about right plus maybe around $40 or so for a joystick, cassette deck and some cartridges, compared to somewhere between $200 and $300 for the recently discounted 64 — which didn't include anything else. (It tells you something about our family finances at the time when a C64 was too expensive.) I immediately started writing my own BASIC programs on it in its perverse little BASIC dialect and when my folks indeed saved up and bought us a C64 system the next year (complete with 1702 monitor and 1541 disk drive), I refused to use it. In retaliation my best interests, my parents forcibly relocated the Tomy to storage and I went on to do even bigger things on the Commodore, making it, not the Tutor, the defining computer of my childhood. That's why there's still a Commodore 128DCR on my desk.

The other reason is that there was never really a simple way to do it. Even when I found out what CPU was actually inside (incredibly a 16-bit TMS 9995, an evolved version of the TMS 9900 in the Texas Instruments 99/4 and 99/4A), there was never a Tomy assembler, and other than its small amount of scratchpad RAM (256 bytes) the entirety of the Tutor's 16K of memory is tied up in the 9918ANL VDP video chip. That sort of architecture was typical for the family, but that also means that almost everything is stored in non-executable VDP RAM, so short of burning your own cartridge EPROMs there's no way to actually create and run a machine language program on the Tutor. The first flashcart for the Tutor didn't exist until around 2016 and it was still all ROM; furthermore, while the 99/4A could have its CPU-addressable RAM expanded (as well as the 99/8, its unreleased successor to which the Tomy Tutor is closely related), there wasn't ever a Tutor RAM expansion cartridge either until very recently. But now there are multiple homebrew options even for obscure home computers like this one, and at last I've got my own assembly language program finally running on it.

And it's all done with its own, better I/O routines (if I do say my own better self) as a basis for bigger projects. But first, a little tour of the Tutor itself, and then we'll dig in.

Tuesday, March 5, 2024

xa (xa65) 2.4.1

A quick one: xa (xa65), André Fachat's compatible fast two-pass cross-assembler for 6502, 65C02, R65C02 and 65816 processors that André and I maintain is now at version 2.4.1. This optionally expands the syntax from 2.4.0 and fixes some bugs primarily with relocatable .o65 objects. As usual, there are even more tests in its extensive conformance test-suite, and it is tested on Linux/ppc64le, Mac OS X (PowerPC, Intel and Apple silicon), AIX (its primary development platform, just to be difficult), and NetBSD/macppc and NetBSD/mac68k. You can download it and read documentation in man(1) format (converted to HTML) from the main xa65 home page. xa is free and open-source under the GNU Public License v2.

Saturday, March 2, 2024

An Apple district manager's Macintosh Portable in 1989-91 (featuring GEIS AppleLink and a look at System 7.0 alpha)

A few months ago I introduced you to one of the more notable Apple pre-production units in my collection, a late prototype Macintosh Portable. But it turns out it's not merely notable for what it is than what it has on it: a beta version of System 6.0.6 (the doomed release that Apple pulled due to bugs), Apple sales databases, two online services — the maligned Mac Prodigy client, along with classic AppleLink as used by Apple staff — and two presentations, one on Apple's current Macintosh line and one on the upcoming System 7. Now that I've got the infamous Conner hard drive it came with safely copied over, it's time to explore its contents some more.
We'll start with this Macintosh Portable itself and Apple's sales channel applications, moving from there to a brief presentation of Apple's Macintosh product line as Apple's own marketing staff would have presented it, at a distinct point in the company's history.
After that, we'll also look at the upcoming System 7.0 circa 1989-90 and a couple very different views of the operating system during its alpha phase.
Finally, after a brief glance at Mac Prodigy, we'll explore a little taste of AppleLink in its classic incarnation on General Electric's Mark III network — and spoof it enough to actually get it to log in.

See more of my general vintage computing projects,
mostly microcomputers, 6502, PalmOS, 68K/Power Mac
and Unix workstations, but that's not all. Be kind, REWIND and PLAY.

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Thanks for reading. -- Cameron Kaiser