Building A DIY MSX Mega Cartridge

September 7, 2024 by Dave Rowntree 9 Comments

[Mike] from Leaded Solder has a soft spot for old computers, and a chance encounter with a friend sent them deep down the deep hole that is the world of 80s and 90s-era Japanese home computers. Many people playing with these machines have all kinds of issues to deal with, such as rotting cartridges, failing components, and just dirt and mank in critical places. [Mike] decided that working on an MSX-standard custom programmable cartridge would be sensible, but then got stuck on how the MSX cartridge mapping works.

The Konami 128K scheme uses 4 to 4-of-8 mapping.

You may recall that the MSX platform is not a single computer but a standard to which many (mainly Japanese) manufacturers designed their products. This disconnected the software writers from the hardware makers and is essentially a mirror of the IBM-PC clone scene.

The MSX is based around the Z80, which has a 16-bit address bus, restricting it to 64K of ROM or RAM. The MSX has two cartridge slots, an ‘internal’ slot for the BIOS and RAM and a fourth for ‘misc’ use. Each of these is mapped internally into the physical address space. The cartridge slots have 64K of addressable space mapped into the Z80 physical space.

If this was not complicated enough, many MSX games and applications exceeded this restriction and added a layer of mapping inside the cartridge using bank switching. A register in the cartridge could change the upper bits of the address allowing ROMs larger than 64K.

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It’s Spreadsheets All The Way Down For This 80s Handheld

September 5, 2024 by Bryan Cockfield 9 Comments

Unlike the today’s consumer computer market, the 1980s were the wild west in comparison. There were all kinds of different, incompatible operating systems, hardware, and programs, all competing against one another, and with essentially no networking to tie everything together. Some of these products were incredibly niche as well, only running one program or having a limited use case to keep costs down. Such was the Convergent WorkSlate, a computer that ran only a spreadsheet with any programs also needing to be built into a spreadsheet.

Upon booting the device, the user is presented with a fairly recognizable blank spreadsheet, albeit with a now-dated LCD display (lacking a backlight) and a bespoke keyboard and cursor that wouldn’t have allowed for easy touch typing. The spreadsheet itself is quite usable though, complete with formatting tools and the capability to use formulas like a modern spreadsheet program would. It also hosted a tape deck for audio and data storage, a modem for communicating with other devices, and an optional plotter-style printer. The modem port is how [Old VCR] eventually interfaces with the machine, although as one can imagine is quite a task for a piece of small-batch technology from the 80s like this. After learning how to send and receive information, a small game is programmed into the machine and then a Gopher interface is built to give the device limited Internet connectivity.

The investigation that [Old VCR] goes into on this project to get this obsolete yet unique piece of hardware running and programmed to do other tasks is impressive, and worth taking a look at especially because spreadsheets like this aren’t Turing-complete, leading to a few interesting phenomenon that most of us wouldn’t come across in the modern computing world. Since only around 60,000 units were ever made it’s difficult to come across these machines, but if you want to take a look at the spreadsheet world of the 80s without original hardware you can still run Lotus 1-2-3 natively in Linux today.

Thanks to [Cameron] for the tip!

The Macintosh Plus Sounds Great If You Do Exactly This With It

August 26, 2024 by Lewin Day 3 Comments

The Macintosh Plus is not exactly known as particularly relevant in the worlds of chiptune or electronic music more broadly. That’s not to say it can’t do anything that sounds cool, however. As [Action Retro] demonstrates, it’s got some really impressive tricks up its sleeve if you know what you’re doing.

The video centers around “Music Mouse”, a piece of software created by Laurie Spiegel for the Macintosh Plus all the way back in 1986. Spiegel saw the Macintosh Plus as a potential instrument for musical expression, with the then-innovative mouse as the key human interface.

[Action Retro] shows off the software, which is able to create rather pleasing little melodies with little more than a swish and a swash across the mousepad. The software makes smart use of scales so you’re not forever dodging around dissonant notes, so it’s quite easy to play something beautiful. He then makes things more interesting by pairing the Macintosh Plus with his favorite guitar pedal—the Old Blood Noise Endeavors Sunlight. It’s a dynamic reverb that really opens up the sonic landscape when paired with the Mac Plus. If you’re looking for a weird avant-garde setup to take on stage at your next noise show, this has to be it.

We’re usually used to seeing Nintendo and Commodore products in the retro computer music space. The Mac makes a nice change. Video after the break.

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The Famous Computer Cafe Has Now Been Archived Online

August 23, 2024 by Lewin Day 4 Comments

You might think that TV stations or production houses would be great at archiving, but it’s not always the case. Particularly from the public access perspective. However, if you’re a fan of The Famous Computer Cafe, you’re in luck! The beloved series has now been preserved on The Internet Archive!

If you’re not familiar with the show, it was a radio program broadcast from 1983 to 1986. It was pumped out of a variety of radio stations in southern and central California in the period. The creators making sure to keep a copy of each episode in reel-to-reel tape format. For years, these tapes were tragically lost, until archivist [Kay Savetz] was able to recover some of them from a recent property sale. From there, a GoFundMe paid for digitization, and the show has been placed on The Internet Archive with the blessings of the original creators.

This is quite the cultural victory, particularly when you observe the list of guests on the show. Timothy Leary, Bill Gates, Jack Tramiel, and even Douglas Adams made appearances in the recovered recordings. Sadly, though, not all the tapes have been recovered. Episodes with Gene Roddenberry, Robert Moog, and Ray Bradbury are still lost to time.

If you fancy a listen, 53 episodes presently exist on the archive. Take a trip back in time and hear from some technological visionaries—and futurists—speaking their minds at the very beginning of the microcomputer era! If you find any particularly salient gems, don’t hesitate to drop them on the tip line.

Happy Birthday To Dad, Retrocomputer Style

August 22, 2024 by Dan Maloney 3 Comments

For those of us who lived through the early 8-bit computing revolution — the tail end, in our case — it’s hard to believe that there’s a second wave of retrocomputing nostalgia underway. But as this bit-banged TRS-80 birthday bonus pack shows, the first generation did a pretty good job passing the retro torch.

With his father’s 70th birthday coming up and full of “borrowed nostalgia” for the good old days, [Josh Sucher] scored a TRS-80 off eBay and experimented with what could be possible. After 50-odd years, the machine needed a bit of TLC, including a new power supply, some keyboard repairs, and the usual recapping. He also had to soup the machine up a bit, given that its original capabilities were so limited.

Chief among these mods was a rudimentary IP stack thanks to a TRS-IO card, which emulates a lot of functionality of the original TRS-80 Expansion Module and adds an ESP-32 for WiFi capability. This allowed [Josh] to get a neat “Dadbot” chatbot going on the machine, using years of his dad’s text messages to train the model. There’s also a game of Go, an RPG based on his parents’ lives, and a local news and weather app. Most impressive, though, is the bit-banged audio app that uses the TRS-80’s cassette interface to play a passable rendition of “Happy Birthday to You.” The video below has the full demo.

It’s clear that this lengthy project was a labor of love, and we approve of the results. It’s been a long, long time since we first caught wind of the TRS-80 through the Radio Shack catalog, and projects like this make us feel like scratching up one for ourselves to play with.

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Historical Microsoft And Apple Artifacts Among First Christie’s Auction Of Living Computers Museum

August 19, 2024 by Maya Posch 9 Comments

Recently the Christie’s auction house released the list of items that would be going up for sale as part of the first lot of Living Computer Museum items, under the banner “Gen One: Innovations from the Paul G. Allen Collection”. One auction covers many ‘firsts’ in the history of computing, including a range of computers like an Apple 1, and a PDP-10, as well as early Microsoft memos and code printouts. The other auctions include such items like a Gemini Spacesuit as worn by [Ed White] and a signed 1939 letter from [Albert Einstein] to [US President Roosevelt] on the discovery by the Germans of a fissionable form of uranium from which a nuclear weapon could be constructed.

We previously reported on this auction when it was first announced in June of this year. At the time many were saddened at seeing the only computer history and its related educational facilities vanish, and there were worries among those who had donated items to the museum what would happen to these now that the museum’s inventory was being put up for sale. As these donations tend to be unconditional, the museum is free to do with the item as they see fit, but ‘being sold at auction’ to probably a private collector was likely not on their mind when filling in the donation form.

As the first auctions kick off in a few days we will just have to wait and see where the museum’s inventory ends up at, but it seems likely that many of these items which were publicly viewable will now be scattered across the globe in private collections.

Top image: A roughly 180° panorama of the “conditioned” room of the Living Computer Museum, Seattle, Washington, USA. Taken in 2014. (Credit: Joe Mabel)

Rebuilding The First Digital Personal Computer

August 16, 2024 by Bryan Cockfield 15 Comments

When thinking of the first PCs, most of us might imagine something like the Apple I or the TRS-80. But even before that, there were a set of computers that often had no keyboard, or recognizable display beyond a few blinking lights. [Artem Kalinchuk] is attempting to recreate one of these very early digital computers, the Kenbak-1, using as many period-correct parts as possible.

Considered by many to be the world’s first personal computer, the Kenbak-1 was an 8-bit machine with 256 bytes of memory, using TTL integrated circuits for the logic as there was no commercially available microprocessor available at the time it was designed. For [Artem]’s build, most of these parts can still be sourced including the 7400-series chips and carbon resistors although the shift registers were a bit of a challenge to find. A custom PCB was built to replicate the original, and with all the parts in order it’s ready to be assembled and put into a case which was built using the drawings for the original unit.

Although [Artem] plans to build a period-correct linear power supply for this computer, right now he’s using a modern switching power supply for testing. The only other major components that are different are the status lamps, in this case switched to LEDs because he wasn’t able to source incandescent bulbs that drew low enough current, and the switches which he’s replaced with MX-style keys. We’ll stay tuned as he builds and tests this over the course of several videos, but in the meantime if you’re curious how this early computer actually worked we featured an emulator for it a while back.

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