retrocomputing

334 Articles

Increasing System Memory With The Flick Of A Switch

June 5, 2023 by 17 Comments

There’s an apocryphal quote floating around the internet that “640K ought to be enough memory for anybody” but it does seem unlikely that this was ever actually said by any famous computer moguls of the 1980s. What is true, however, is that in general more computer memory tends to be better than less. In fact, this was the basis for the Macintosh 512k in the 1980s, whose main feature was that it was essentially the same machine as the Macintosh 128k, but with quadruple the memory as its predecessor. If you have yet to upgrade to the 512k, though, it might be best to take a look at this memory upgrade instead.

The Fat Mac Switcher, as it is called by its creator [Kay Koba], can upgrade the memory capability of these retro Apple machines with the simple push of a switch. The switch and controller logic sit on a separate PCB that needs to be installed into the computer’s motherboard in place of some of the existing circuitry. The computer itself needs its 16 memory modules replaced with 41256 DRAM modules for this to work properly though, but once its installed it can switch seamlessly between 512k and 128k modes.

Another interesting quirk of the retro Macintosh scene is that the technically inferior 128k models tend to be valued higher than the more capable 512k versions, despite being nearly identical otherwise. There are also some other interesting discussions on one of the forum posts about this build as well. This module can also be used in reverse; by installing it in a Macintosh 512k the computer can be downgraded to the original Macintosh 128k. For this the memory modules won’t need to be upgraded but a different change to the motherboard is required.

A product like this certainly would have been a welcome addition in the mid 80s when these machines were first introduced, since the 512k was released only months after the 128k machines were, but the retrocomputing enthusiasts should still get some use out of this device and be more able to explore the differences between the two computers. If you never were able to experience one of these “original” Macintosh computers in their heyday, check out this fully-functional one-third scale replica.

Commodore 64 Web Server Brings 8-Bit Into The Future

June 1, 2023 by 28 Comments

These days, most webservers are big hefty rackmount rigs with roaring fans in giant datacenters. [naDDan]’s webserver is altogether more humble, as it runs on a single Commodore 64. 

The C64 is running Contiki OS, an operating system for 6502-based computers. It’s built with an eye to networking, requiring ethernet hardware for full functionality. In [naDDan]’s case, he’s outfitted his C64 with an ETFE network adapter in the cartridge port to get it online. It serves up the HTML file off a 1541C floppy drive, with the drive buzzing away every time someone loads up the page.

The page itself is simple, showing some basic information on a simple blue background. There is some scrolling text though, as is befitting the 8-bit era. It’s also available in four languages.

[naDDan’s] server can be found here, according to his video, but at the time of writing, it was down for the count. Whether that’s due to a dynamic DNS issue or the simple fact that an 8-bit 6502 isn’t up to heavy traffic is up for debate. Regardless, try for yourself and see how you go. Video after the break.

New Zealand’s First Microcomputer May Be This 1802

May 24, 2023 by 13 Comments

Hardware hackers of a certain age likely got started with microcontrollers via the RCA 1802 — a relatively easy-to-use processor that was the subject of several excellent articles in Popular Electronics magazine back in the late 1970s. [Al’s Geek Lab] has an interview with [Hugh Anderson], who saw the articles and eventually designed the HUG1802, which may be the first microcontroller kit designed and sold in New Zealand.

The 1802 was very attractive at the time since it was inexpensive, static, didn’t require exotic voltages, and had a DMA system that allowed you to load software without complex ROMs. He initially marketed a kit unsuccessfully until an Australian company convinced him to create a proper PC board — the resulting kit was sold to about 100 customers.

The HUG1802 reminded us somewhat of the Quest Super Elf since it had a keypad, a cassette interface, and even a TV output. The 1802 had a DMA-enabled chip that made crude memory-mapped video output. The computer eventually morphed into the ETI 660, which they talk about at the end of the interview.

A lot of people built 1802 computers back in those days. If you don’t have an 1802, but you have an Arduino… ell, there’s always emulation.

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Commodore 64 Upgrade In Modern Package

May 23, 2023 by 50 Comments

While the Commodore 64 was an immensely popular computer for its time, and still remains a strong favorite within the retrocomputing community, there’s a reason we’re not using modern Commodore-branded computers today. Intense competition, company mismanagement, and advancing beyond 8-bit computers too late in the game all led to the company’s eventual downfall. But if you’re still a Commodore enthusiast and always wished you were able to get an upgraded C64, you might want to take a look at the Commander X16, a modern take on this classic computer.

We’ve actually seen the Commander X16 before, but this was back in its early days of prototyping and design. This video from [Adrian’s Digital Basement], also linked below the break, takes a look at how it’s come in the four years since [David Murray] started this project. At its core, it’s an 8-bit 6502-based computer like you’d find in the 1980s but built with new components. There are some more modern updates as well such as the ability to use an SD card as well as built-in SNES controller ports, but the real magic here is the VERA module. Built around an FPGA, this module handles graphics, some of the audio, and the storage capabilities and does all of these things much better than the original Commodore, while still being faithful to what made these computer great.

While the inclusion of the FPGA might offend some of the most staunch 8-bit purists, it turns out to be necessary due to the lack of off-the-shelf video chips and really makes this build shine in the end. It’s also capable of running 6502-based software from other machines too, including the original NES. The VERA module makes it possible to run other software too, including a sample of Sonic the Hedgehog from the Sega Genesis which [Adrian] demonstrates in his video. 6502-based computers are quite versatile as the Commander X16 demonstrates, and it’s even possible to build a rudimentary 6502 on a breadboard with just a few parts.

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A Look Back At Computer Displays

May 21, 2023 by 10 Comments

These days, our video cards are actually as powerful as yesterday’s supercomputer and our monitors are bigger than the TVs most of us had as kids. But how did we get there? [RetroBytes] covers computer displays starting with the Colossus computer to today.

Back in the days of Colossus, of course, a display was actually a TeleType-like device printing on a roll of paper. The Manchester Baby actually had a crude display which was actually a Williams tube (no relation) that used phosphor persistence to store data. You could physically see memory on the tube or monitor it on a parallel tube — an early form of memory-mapped display.

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WordStar Reborn

May 9, 2023 by 46 Comments

Wordstar was the word processor that helped sell the personal computer. At one time, it was ubiquitous, and many authors had a hard time giving it up. Some, like George R. R. Martin, apparently are still refusing to give it up. But most of us have moved on. Thanks to an open-source clone, WordTsar, you may not have to. This is a modern interpretation of our old friend.

Programmers that write were especially fond of WordStar since it had a non-document mode and was often the best text editor you had available for writing code. Being able to do your documentation without switching brain gears is useful, too. Touch typists love the efficiency of easy control of things without resorting to cursor keys or a mouse — the same thing vi and emacs fans enjoy but in a different way.

The software runs on multiple platforms and has some new features. Installation on Linux is easy because it is packaged in an AppImage file. Of course, you can also fire up your best CP/M machine, replica, or emulation and run the real WordStar, but — honestly — WordTsar seems more practical if you wanted to go back to using this kind of wordprocessor or editor for everyday use.

Of course, some word processors were actual hardware. If you want some cheap CP/M hardware, that’s easy enough, too.

Soviet-Era Computer Is Both A Mystery And A Disaster

May 7, 2023 by 56 Comments

There are plenty of bizarre computers around from the 70s through the 90s before the world somewhat standardized around various duopolies of hardware vendors and operating systems. Commodore, Atari, and even Apple had some bizarre machines from this era but for our money, the most unusual systems come out of the Eastern Bloc. We’ve featured plenty of these before, and the latest is a Robotron CM1910 which comes to us from [Chernobyl Family] via YouTube.

Built in East Germany behind the wall, the Robotron factories had easier access to Soviet than western parts, but the latter were also available when necessary. Hence it’s built on an Intel 8086 processor, which seems common enough for the era, but after opening the case some non-standard construction becomes apparent.

The first is a densely-packed array of circuit boards and wiring, far beyond what a western PC might have included in this time. This also partially explains its massive 25 kg weight. It does include a hard drive, two floppy disk drives, a large dedicated graphics card, and a modem which all contribute as well. The overall design philosophy of the machine was a headscratcher too, which would have involved near-complete dismantling of the machine to access or repair some of the parts, as well as some hidden peripheral and drive controllers in questionable locations.

From the looks of it, we doubt this computer will see any uptime anytime soon, although they did at least restore the keyboard. With all of the chips accessible on PCBs, it might be possible to get this machine up and running again although it would take a massive effort thanks to its non-standard design and construction, and might also require help from builds like this to replace or emulate some of the hardware.

Thanks to [Stephen] for the tip!

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