Giant Brains, Or Machines That Think

Last week, I stumbled on a marvelous book: “Giant Brains; or, Machines That Think” by Edmund Callis Berkeley. What’s really fun about it is the way it sounds like it could be written just this year – waxing speculatively about the future when machines do our thinking for us. Except it was written in 1949, and the “thinking machines” are early proto-computers that use relays (relays!) for their logic elements. But you need to understand that back then, they could calculate ten times faster than any person, and they would work tirelessly day and night, as long as their motors keep turning and their contacts don’t get corroded.

But once you get past the futuristic speculation, there’s actually a lot of detail about how the then-cutting-edge machines worked. Circuit diagrams of logic units from both the relay computers and the brand-new vacuum tube machines are on display, as are drawings of the tricky bits of purely mechanical computers. There is even a diagram of the mercury delay line, and an explanation of how circulating audio pulses through the medium could be used as a form of memory.

All in all, it’s a wonderful glimpse at the earliest of computers, with enough detail that you could probably build something along those lines with a little moxie and a few thousands of relays. This grounded reality, coupled with the fantastic visions of where computers would be going, make a marvelous accompaniment to a lot of the breathless hype around AI these days. Recommended reading!

Homebrew Reader Brings Paper Tape Programs Back To Life

We may be a bit biased, but the storage media of yesteryear has so much more personality than that of today. Yes, it’s a blessing to have terabyte SD cards smaller than your pinky nail and be able to access its data with mind-boggling speed. But there’s a certain charm to a mass storage device that can potentially slice off your finger.

We’re overstating the dangers of the venerable paper tape reader, of course, a mass storage device that [David Hansel] recreated a few years back but we only just became aware of. That seems a bit strange since we’ve featured his Arduino-based Altair 8800 simulator, which is what this tape reader is connected to. Mechanically, the reader is pretty simple — just a wooden frame to hold the LEGO Technic wheels used as tape reels, and some rollers to guide the tape through a read head. That bit is custom-made and uses a pair of PCBs, one for LEDs and one for phototransistors. There are nine of each — eight data bits plus the index hole — and the boards are sandwiched together to guide the paper tape.

The main board has an ATmega328 which reads the parallel input from the read head and controls the tape motor. That part is important thanks to Altair Basic’s requirement for a 100- to 200-ms delay at the end of each typed line. The tape reader, which is just being used as sort of a keyboard wedge, can “type” a lot faster than that, so the motor speed is varied using PWM control as line length changes.

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Shipping Your Illicit Software On Launch Hardware

In the course of a career, you may run up against projects that get cancelled, especially those that are interesting, but deemed unprofitable in the eyes of the corporate overlords. Most people would move, but [Ron Avitzur] just couldn’t let it go.

In 1993, in the midst of the transition to PowerPC, [Avitzur]’s employer let him go as the project they were contracted to perform for Apple was canceled. He had been working on a graphing calculator to show off the capabilities of the new system. Finding his badge still allowed him access to the building, he “just kept showing up.”

[Avitzur] continued working until Apple Facilities caught onto his use of an abandoned office with another former contractor, [Greg Robbins], and their badges were removed from the system. Not the type to give up, they tailgated other engineers into the building to a different empty office to continue their work. (If you’ve read Kevin Mitnick‘s Ghost in the Wires, you’ll remember this is one of the most effective ways to gain unauthorized access to a building.)

We’ll let [Avitzur] tell you the rest, but suffice it to say, this story has a number of twists and turns to it. We suspect it certainly isn’t the typical way a piece of software gets included on the device from the factory.

Looking for more computing history? How about a short documentary on the Aiken computers, or a Hack Chat on how to preserve that history?

[Thanks to Stephen for the tip via the Retrocomputing Forum!]

Restoring A Vintage CGA Card With Homebrew HASL

Right off the bat, we’ll stipulate that what [Adrian] is doing in the video below isn’t actual hot air solder leveling. But we thought the results of his card-edge connector restoration on a CGA video card from the early 80s was pretty slick, and worth keeping in mind for other applications.

The back story is that [Adrian], of “Digital Basement” YouTube fame, came across an original IBM video card from the early days of the IBM-PC. The card was unceremoniously dumped, probably due to the badly corroded pins on the card-edge bus connector. The damage appeared to be related to a leaking battery — the corrosion had that sickly look that seems to only come from the guts of batteries — leading him to try cleaning the formerly gold-plated pins. He chose naval jelly rust remover for the job; for those unfamiliar with this product, it’s mostly phosphoric acid mixed with thickeners and is used as a rust remover.

The naval jelly certainly did the trick, but left the gold-plated pins a little worse for the wear. Getting them back to their previous state wasn’t on the table, but protecting them with a thin layer of solder was easy enough. [Adrian] used liquid rosin flux and a generous layer of 60:40 solder, which was followed by removing the excess with desoldering braid. That worked great and got the pins on both sides of the board into good shape.

[Adrian] also mentioned a friend who recommended using toilet paper to wick up excess solder, but sadly he didn’t demonstrate that method. Sounds a little sketchy, but maybe we’ll give it a try. As for making this more HASL-like, maybe heating up the excess solder with an iron and blasting the excess off with some compressed air would be worth a try.

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The World’s First DIY Minicomputer Was Almost Australian

The EDUC-8, a DIY minicomputer design that came out in “Electronics Australia” magazine, was almost the world’s first in August 1974. And it would have been tied for the world’s first if inventor [Jamieson “Jim” Rowe] hadn’t held back from publishing to rework the design to expand the memory to a full 256 bytes. The price of perfectionism?

Flash forward 50 years, and [Gwyllym Suter] has taken on the job of recreating the EDUC-8 using modern PCBs, but otherwise staying true to the all-TTL design. He has all of his schematics up on the project’s GitHub, but has also sent us a number of beauty shots that we’re including below. Other than the progress of PCB tech and the very nice 3D-printed housing, they look identical. We have to admit that we love those wavy hand-drawn traces on the original, but we wouldn’t be sad about not having to solder in all those jumpers.

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Baldur’s Gate III Comes To The TRS-80 Model 100

To say that Tandy’s TRS-80 Model 100 was an influential piece of computer hardware would be something of an understatement. While there’s some debate over which computer can historically be called the “first laptop”, the Model 100 was early enough that it helped influence our modern idea of portable computing. It was also one of the most successful of these early portables, due in part to how easy it was to write your own software for it using the built-in BASIC interpreter.

But as handy and capable as that integrated development environment might have been, it never produced anything as impressive as this Baldur’s Gate III “demake” created by [Alex Bowen]. Written in assembly, the game’s engine implements a subset of the Dungeons & Dragons Systems Reference Document (SRD), and is flexible enough that you could use it to produce your own ASCII art role-playing game that can run on either a Model 100 emulator like Virtual-T or on the real hardware.

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A C64 SID Replacement With Built-in Games

Developer [frntc] has recently come up with a smaller and less expensive way to not only replace the SID chip in your Commodore 64 but to also make it a stereo SID! To top it off, it can also hold up to 16 games and launch them from a custom menu. The SIDKick Pico is a simple board with a Raspberry Pi Pico mounted on top. It uses a SID emulation engine based on reSID to emulate both major versions of the SID chip — both the 6581 and the 8580. Unlike many other SID replacements, the SIDKick Pico also supports mouse and paddle inputs, meaning it replaces all functionality of the original SID!

Sound can be generated in three different ways: either using PWM to create a mono audio signal that is routed out via the normal C64/C128 connectors, an external PCM5102A DAC board, or using a different PCB design that has pads for an on-board DAC and TL072 op-amp. While many Commodore purists dislike using replacement chips, the reality is that all extant SID chips were made roughly 40 years ago, and as more and more of them fail, options like the SIDKick Pico are an excellent way to keep the sound of the SID alive.

If you want to hear the SIDKick Pico in action, you can check out the samples on the linked GitHub page, or check out the video below by YouTuber Wolfgang Kierdorf of the RETRO is the New Black channel. To get your hands on a SIDKick Pico, you can follow the instructions on the GitHub page for ordering either bare PCBs or pre-assembled PCBs from either PCBWay or your board manufacturer of choice.

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