Vintage Computer Festival Southern California

October 16, 2023 by Adam Fabio 13 Comments

The Vintage Computer Festival is coming to sunny Southern California in February 2024. That’s right, bring your Commodores, your Tandys, your PDP-11s, and Altairs. The world of retrocomputing will be open to vendors, visitors, and exhibitors at The Hotel Fera Events Center in Orange, California on February 17th and 18th, 2024.

If you’re thinking there already is a VCF out west, you’d be right. VCF West was held in August at the Computer History Museum. The CHM is in Mountain View, California. That puts it nearly at the epicenter of the microcomputer revolution of the ’70s and ’80s.

Southern California still had plenty of computer enthusiasts though. For the non-geographically inclined amongst us, SoCal is nearly 6 hours from Mountain View by car. We’re sure we’ll see many familiar faces at SoCal, along with plenty of new ones.

The Vintage Computer Federation holds several events across the country each year. You might have heard some music from VCF Midwest 2023 back in September. Hackaday was also out in force at VCF East this year, where our own [Bil Herd] moderated a panel of vintage computer YouTubers including [Usagi Electric], [Adrian’s Digital Basement], and [FranLab].

RP2040 Emulator Brings The Voice Of The 80s Back To Life

September 22, 2023 by Dan Maloney 23 Comments

You may not have heard, but there’s a chip shortage out there. And it’s not just the fancy new chips that are in short supply; the chips that were fancy and new back when you could still buy them from Radio Shack are getting hard to come by, too. For different reasons, of course, but it does pose a problem that requires a little hacking to fix.

The chip in question here is the General Instrument SP0256, a 1980s-era speech synthesizer chip that [Andrew Menadue] relies on. The LSI chip stored 59 unique allophones, or basic sounds the vocal tract is capable of, and synthesized speech by rapidly concatenating these sounds. The chip and its descendants made regular appearances in computers and games throughout the 80s, so chances are good you’ve heard it. If not, think WarGames (yes, we know that wasn’t actually a computerized voice) or [Stephen Hawking] and you’ll be pretty close.

[Andrew]’s need for such a chip stems from his attempts to give voice to his collection of Psion Organisers, another 80s relic that was one of the first pocket computers. Some time ago he built a speech board for the Psion based on the SP0256-AL2, but had to resort to building an emulator for the chip since none were to be had. The emulator uses an RP2040 and lives on a PCB that has the same footprint as the original chip, so it can just plug right in. He dug up WAV files of the allophones and translated those to sequences of bytes, allowing the RP2040 to output the correct sounds as they’re called for. Speaker problems notwithstanding, it sounds pretty good in the video below.

We’ve featured a fair number of SP0256 projects before, on everything from Amstrad to Z80. We’ve also shown off a few of [Andrew]’s builds before, including this exploration of the voltage tolerance of the RP2040.

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Building RAM Expansions For The DEC Rainbow 100

September 14, 2023 by Lewin Day 3 Comments

It’s hard enough to get your hands on a forgotten computer from yesteryear. It’s even more difficult to get accessories like RAM expansions and graphics cards, because half the time they’re just discarded as random e-waste when they’re outside of their original context. [na103] has solved this problem for the DEC Rainbow 100 to a degree, by building new RAM expansions and graphics cards from scratch.

In the case of the RAM expansion, the design [na103] built is capable of boosting a Rainbow 100 computer to a full 896KB. This is more than other contemporary IBM machines like the 8088 XT, which had an architecture-enforced limit of 640 KB. It was rebuilt from some notes and original DEC schematics.

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Book8088 Slows Down To Join The Demoscene

September 12, 2023 by Dan Maloney 9 Comments

As obsolete as the original IBM Model 5150 PC may appear, it’s pretty much the proverbial giant’s shoulders upon which we all stand today. That makes the machine worth celebrating, so much so that we now have machines like the Book8088, a diminutive clamshell-style machine made from period-correct PC chips; sort of a “netbook that never was.”

But the Book8088 only approximates the original specs of the IBM PC, making some clever hardware hacks necessary to run some of the more specialized software that has since been developed to really stretch the limits of the architecture. [GloriousCow]’s first steps were to replace the Book8088’s CPU, an NEC V20, with an actual 8088, and the display controller with a CGA-accurate Motorola MC6845. Neither of these quite did the trick, though, at least not on the demanding 8088MPH demo, which makes assumptions about CPU speed based on the quirky DRAM refresh scheme used in the original IBM PC.

Knowing this, [GloriousCow] embarked on a bodge-fest aimed at convincing the demo that the slightly overclocked Book8088 was really just a 4.77-MHz machine with a CGA adapter. This involved cutting a trace on the DMA controller and reconnecting it to the machine’s ~~PIO~~ timer chip, with the help of a 74LS74 flip-flop, a chip that made an appearance in the 5150 but was omitted from the Book8088. Thankfully, the netbook has plenty of room for these mods, and with the addition of a little bit of assembly code, the netbook was able to convince 8088MPH that it was running on the correct hardware.

We thoroughly enjoyed this trip down the DMA/DRAM rabbit hole. The work isn’t finished yet, though — the throttled netbook still won’t run the Area 5150 demo yet. Given [GloriousCow]’s recent Rust-based cycle-accurate PC emulation, we feel pretty good that this will come to pass soon enough.

Clock Hack Gives DEC Rainbow A New Lease On Life

September 12, 2023 by Dan Maloney 21 Comments

In retrocomputing circles, it’s often the case that the weirder and rarer the machine, the more likely it is to attract attention. And machines don’t get much weirder than the DEC Rainbow 100-B, sporting as it does both Z80 and 8088 microprocessors and usable as either a VT100 terminal or as a PC with either CP/M or MS-DOS. But hey — at least it got the plain beige box look right.

Weird or not, all computers have at least a few things in common, a fact which helped [Dr. Joshua Reichard] home in on the problem with a Rainbow that was dead on arrival. After a full recapping — a prudent move given the four decades since the machine was manufactured — the machine failed to show any signs of life. The usual low-hanging diagnostic fruit didn’t provide much help, as both the Z80 and 8088 CPUs seemed to be fine. It was then that [Joshua] decided to look at the heartbeat of the machine — the 24-ish MHz clock shared between the two processors — and found that it was flatlined.

Unwilling to wait for a replacement, [Joshua] cobbled together a temporary clock from an Arduino Uno and an Si5351 clock generator. He connected the output of the card to the main board, whipped up a little code to generate the right frequency, and the nearly departed machine sprang back to life. [Dr. Reichard] characterizes this as a “defibrillation” of the Rainbow, and while one hates to argue with a doctor — OK, that’s a lie; we push back on doctors all the time — we’d say the closer medical analogy is that of fitting a temporary pacemaker while waiting for a suitable donor for a transplant.

This is the second recent appearance of the Rainbow on these pages — [David] over at Usagi Electric has been working on the graphics on his Rainbow lately.

Linux Fu: The Old School Terminal

August 23, 2023 by Al Williams 40 Comments

Maybe you have a vintage old-school computer. Maybe you have a replica. Maybe you just want to run SIMH and relive the glory days of CP/M or VMS. The problem is, it looks kind of silly to have CP/M running in your beautiful X11 terminal window full of 3D animations, opacity effects, and special fonts. You could buy an old CRT monitor. That would be cool, too, because on a modern screen, you don’t get scan lines and all the crummy artifacts that go along with an electron beam and phosphor display device. Or you can grab retro-cool-term.

Even if you don’t have an old computer, the program will work fine to simply run your shell for everyday use. Confound the youngsters when they see your terminal with scan lines and CRT jitter updating the latest packages.

What Is It?

If you want a shell in a GUI, you used to use xterm, although most people use something more modern. I use Konsole, but some like RXVT or whatever terminal your distro favors. Cool-retro-term is just a replacement for this. By default, it only opens a shell prompt.

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Ask Hackaday: Why Retrocomputing?

August 16, 2023 by Al Williams 81 Comments

I recently dropped in on one of the Vintage Computer Festival events, and it made me think about why people — including myself — are fascinated with old computer technology. In my case, I lived through a lot of it, and many of the people milling around at VCF did too, so it could just be nostalgia. But there were also young people there.

Out of curiosity, I asked people about the appeal of the old computers on display there. Overwhelmingly, the answer was: you can understand the whole system readily. Imagine how long it would take you to learn all the hardware and software details of your current desktop computer CPU. Then add your GPU, the mass storage controllers, and your network interface. I don’t mean knowing the part numbers, specs, and other trivialities. I mean being able to program, repair, and even enhance it.

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