Retrocomputing

1675 Articles

Another World On The Apple II

August 26, 2019 by 11 Comments

What’s more fun than porting an old game released for an old system such as the Apple IIgs to its 10-year-older predecessor, the Apple II from 1977? Cue [Deater]’s port of the classic video game ‘Another World‘ to the original Apple II. As was fairly obvious from the onset, the main challenges were with the amount of RAM, as well as with the offered graphics resolutions.

Whereas the Apple II could address up to 48 kB of RAM, the 16-bit Apple IIgs with 65C816 processor could be upgraded to a maximum of 8 MB. The graphics modes offered by the latter also allowed ‘Another World’ to run at a highly playable 320×200, whereas the ported version is currently limited to the ‘low resolution’ mode at 40×48 pixels.

The game itself still needs a lot of work to add missing parts and fix bugs, but considering that it has been implemented in 6502 assembler from scratch, using just the gameplay of the IIgs version as reference, it’s most definitely an achievement which would have earned [Deater] a lot of respect back in the late ’80s as well.

Feel free to check out the Github page for this project, grab a floppy disk image from the project page and get playing. Don’t forget to check out the gameplay video linked after the break as well.

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Vintage Console Becomes The Calculator It Appears To Be

August 25, 2019 by 9 Comments

What’s sitting on [Bob Alexander]’s desk in the video below did not start out life as the desktop calculator it appears to be. Turning it into a standalone calculator with features the original designers couldn’t imagine turned out to be an interesting project, and a trip down the retrocomputing rabbit hole.

A little explanation is in order. Sure, with its Nixie display, calculator keypad, and chunky mid-century design, the Wang 360 desktop console looks like a retro calculator. But it’s actually only a dumb terminal for a much, MUCH bigger box, called the Electronic Package, that would fit under a desk. The foot-warming part that was once connected to [Bob]’s console by a thick cable that had been unceremoniously lopped off by a previous owner. [Bob] decided to remedy the situation with modern electronics. The console turned out to have enough room for a custom PCB carrying a PIC32, some level-shifting components, power supply modules that include the high-voltage supply for the Nixies, and a GPS module because Nixies and clocks just go together. The interesting bit is the programming; [Bob] chose to emulate the original Wang methods of doing math, which include multiplication by logarithmic addition. Doing so replicates the original look and feel of the calculator down to the rapid progression of numbers across the Nixies as the logarithms are calculated using the display registers.

We normally frown on vintage gear being given modern guts, but in this case [Bob] hit just the right balance of new and old, And given that the Electronic Packages these consoles were connected to go for $1500 or more on eBay, it was a better choice than letting the console go to scrap. A similarly respectful approach was taken with this TRS80 Model 100 revival.

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An Entire PDP-11 On Your Bench

August 24, 2019 by 25 Comments
A PDP-11 at The National Museum Of Computing, Bletchley, UK.
A PDP-11 at The National Museum Of Computing, Bletchley, UK.

The DEC PDP series of minicomputers occupy a special place in computing history for us, because as the workhorses of commercial computing from the 1960s through to some time in the 1990s they provided the bedrock upon which so many of the computing technologies we take for granted today were built. If we think of any PDP, the chances are we’ll be imagining fridge-sized units with panels of blinkenlights that have become iconic in their own right. But that wasn’t the sum of PDP hardware, for at the end of the series of machines there were produced PDP-11s containing what had previously needed those fridge-sized units on a single chip-sized module. [Peter Schranz] had one of these modules, a DCJ11 that he’d salvaged in the 1990s, and he set to with it in making a modern desktop version of a PDP-11.

The PDP-11/hack is a PDP-11 as a set of daughter cards on a lightly modified Q-bus backplane. The DCJ11 and its memory sit on one, an emulated disc controller on another, and finally a multifunction board brings together clock and serial functions. Where the original would have had acres of 74 logic the PDP-11/hack uses more modern CPLDs and microcontrollers to provide glue logic and to emulate now-obsolete components. Given a serial terminal it will boot and run PDP operating systems and software, though it lacks a set of blinkenlights to display its status.

This isn’t the first PDP-11 using this chip we’ve shown you.

Modern Linux Runs On Ancient Toshiba

August 23, 2019 by 65 Comments

While Microsoft no longer supports those of its operating systems that were in heavy use into the early 2000s, support for old hardware is not typically something that you will have to worry about if you run Linux on your machines. Sure, there will be driver issues from time to time, and you might have to do some things by hand, but if you’re using legacy hardware you’ll want a Linux distribution of some sort. Especially if you’re running it on one of the first laptops to ever feature a Pentium processor of any kind.

This is a Toshiba T4900CT which [MingcongBai] has been able to spruce up by installing a simplified version of the AOSC OS Linux distribution. The distribution is known for its simplified user interface, and this particular one runs a “Retro” command-line-only version. Upon startup (which takes over two minutes), the user can view the hardware and software specs: Linux kernel 4.19.67 (released within the past year) on a 75 MHz Intel processor.

Getting old equipment to work, even if the software is available, is a challenge and this one stands out for the historical noteworthiness of the laptop. We didn’t see it connect to the Internet, but if it ever does we still keep Retro Hackaday up specifically for situations like this.

Dirty Tricks For 6502 Programming

August 20, 2019 by 30 Comments

We know the 6502 isn’t exactly the CPU of choice for today’s high-performance software, but with the little CPU having appeared in so many classic computers — the Apple, the KIM-1, The Commodores, to name a few — we have a real soft spot for it. [Janne] has a post detailing the eight best entries in the Commodore 64 coding competition. The goal was to draw an X on the screen using the smallest program possible. [Janne] got 56 bytes, but two entrants clocked in at 34 bytes.

In addition to the results, [Janne] also exposes the tricks people used to get these tiny programs done. Just looking at the solution in C and then 6502 assembly is instructive. Naturally, one trick is to use the existing ROM code to do tasks such as clearing the screen. But that’s just the starting point.

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You Need A Cyberdeck, This Board Will Help

August 16, 2019 by 8 Comments

In 1984, William Gibson’s novel Neuromancer helped kick off the cyberpunk genre that many hackers have been delighting in ever since. Years before Tim Berners-Lee created the World Wide Web, Gibson was imagining worldwide computer networks and omnipresent artificial intelligence. One of his most famous fictional creations is the cyberdeck, a powerful mobile computer that allowed its users to navigate the global net; though today we might just call them smartphones.

While we might have the functional equivalent in our pockets, hackers like [Tillo] have been working on building cyberdecks that look a bit more in line with what fans of Neuromancer imagined the hardware would be like. His project is hardly the first, but what’s particularly notable here is that he’s trying to make it easier for others to follow in his footsteps.

There’s a trend to base DIY cyberdecks on 1980s vintage computer hardware, with the logic being that it would be closer to what Gibson had in mind at the time. Equally important, the brutalist angular designs of some of those early computers not only look a lot cooler than anything we’ve got today, but offer cavernous internal volume ripe for a modern hardware transfusion. Often powered by the Raspberry Pi, featuring a relatively small LCD, and packed full of rechargeable batteries, these cyberdecks make mobile what was once anchored to a desk and television.

[Tillo] based his cyberdeck on what’s left of a Commodore C64c, reusing the original keyboard for that vintage feel. That meant he needed to adapt the keyboard to something the Raspberry Pi could understand, for which some commercially available options existed already. But why not take the idea farther for those looking to create their own C64c cyberdecks?

He’s currently working on a new PCB specifically designed for retrofitting one of these classic machines with a Raspberry Pi. The board includes niceties like a USB hub, and should fill out some of those gaping holes left in the case once you remove the original electronics. [Tillo] has already sent the first version of his open source board out for fabrication, so hopefully we’ll get an update soon.

In the meantime, you might want to check out some of the other fantastic cyberdeck builds we’ve covered over the last couple of years.

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Giving The Amstrad CPC A Voice And A Drum Kit

August 12, 2019 by 7 Comments

Back in the ’80s, home computers weren’t capable of much in terms of audio or multimedia as a whole. Arguably, it wasn’t until the advent of 16-bit computers such as the Amiga that musicians could make soundtrack-quality music without having to plug actual studio gear up to their machines. [Michael Wessel] is trying to bring some of that and many more features to the Amstrad CPC with his ambitious LambdaSpeak 3 project, an expansion card built completely up from scratch and jam-packed with features.

First, and likely giving it its name, is the speech synthesizer. [Michael] has made an emulation mode where his card can act just like the original SSA-1 expansion, being able to be controlled by the same software as back then. By default, the card offers this mode with an Epson S1V30120 daughterboard (which is based on DECTalk synthesis), however for further authenticity you also have the option of fitting it with an SP0256-AL2 chip, the same one used in the original Amstrad hardware in 1985.

As for the more musical part of the project, the board supports 4-channel PCM playback, much like the Amiga’s sound offering. This can be used for a drum machine sequencer program, and it has an Amdrum mode, emulating another expansion from the original Amstrad days. Sample playback can also be used alongside the speech synthesis as shown here, with random allophone beats that wouldn’t sound out of place in a Kraftwerk recording. Finally, by using the UART interface included on the LambdaSpeak, you can also turn the CPC itself into a synth by giving it MIDI in/out and interfacing a controller in real time with the computer’s AY-3-8912 sound chip.

If you like modern expansions giving old computers new life, did you know that you can get just about any retro computer online, perhaps a TRS-80, an Amiga and even a Psion Organizer? And if you’re interested in just using old systems’ sound chips with modern USB MIDI controllers, it’s easy to make a microcontroller do all the heavy lifting.

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