Retrocomputing

1675 Articles

Displaying Bitmaps On The Apple II

October 5, 2018 by 34 Comments

The Apple II was the popular darling that truly kicked off the ascention of the company that would later bring you darlings such as the iMac, iPod, and iPhone. The brainchild of the legendary Steve Wozniak, it was a low-cost home computer that made use of some interesting compromises to create video output with the bare minimum components. This can make it difficult if you want to output full-bitmap graphics on the Apple II – but it is certainly possible.

[cybernesto] set about completing this task, and released VBMP on GitHub. Programmed in assembly, it builds upon the work of democoder Arnaud Cocquière to display bitmap images on the vintage 6502-powered machine. Capable of displaying monochrome images in 560 x 192 or sixteen colors in 140 x 192, it loads slowly but does get the job done.

We’ve seen similar development underway elsewhere, too – on this vintage satellite tracker project. [Keplermatic] reports that their code runs at a similar speed to the VBMP loader, despite doing several things differently. It’s also available over at GitHub, for your reading pleasure.

If you’re looking to achieve something similar with your vintage hardware, it’s worth a look. Having the source available makes integrating it into further projects a snap. Learning to program these older machines can be challenging, but that’s half the fun – and when you build something awesome, be sure to drop it on the tips line.

Ants, Dirt, Rain, And The Commodore 64 That Wouldn’t Quit

October 3, 2018 by 34 Comments

Some electronics gear is built for the roughest conditions. With rugged steel cases, weatherproof gaskets, and cables passing through sealed glands, these machines are built to take the worst that Mother Nature can throw at them, shrugging off dust, mud, rain, and ice. Consumer-grade computers from the start of the home PC era, however, are decidedly not such machines.

Built to a price point and liable to succumb to a spilled Mountain Dew, few machines from that era that received any kind of abuse lived to tell the tale. Not so this plucky Commodore 64C, which survived decades exposed to the elements. As [Adrian Black] relates in the video below, this machine was on a scrap heap in an Oregon field, piled there along with other goodies by one of those “pickers” that reality TV loves so much. The machine was a disaster. It hadn’t been soaked in oil, but it was loaded with pine needles and an ant colony. The worst part, though, was the rust. The RF shielding had corroded into powder in some places, leaving reddish rust stains all over the place. Undeterred, [Adrian] gave the machine a good bath, first in water, then in isopropanol. Liberal applications of Deoxit helped with header connections, enough to see that the machine miraculously booted. It took some finagling, especially with the 6526 I/O controller, but [Adrian] was eventually able to get everything on the motherboard working, even the sound chip.

Whether this machine survived due to good engineering or good luck is debatable, but it’s a treat to see it come back to life. We hope a full restoration is in the works, not least as a way to make up for the decades of neglect.

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Pristine Apple I Sells At Auction For A Jaw-Dropping Price

October 1, 2018 by 29 Comments

If you think Apple products are overpriced now, wait until they’re 50 years old.

This original Apple I recently sold at auction for $375,000, making it one of the most expensive 6502-based computers in history. Given that only something like 60 or 70 of the machines were ever made are known to exist, most built by hand by [Jobs] and [Wozniak], it’s understandable how collectors fought for the right to run the price up from the minimum starting bid of $50,000. And this one was particularly collectible. According to the prospectus, this machine had few owners, the most recent of whom stated that he attended a meeting of the legendary Homebrew Computer Club to see what all the fuss was. He bought it second-hand from a coworker for $300, fiddled with it a bit, and stashed it in a closet. A few years later, after the Apple ][ became a huge phenomenon, he tried to sell the machine to [Woz] for $10,000. [Woz] didn’t bite, and as a result, the owner realized a 125,000% return on his original investment, before inflation.

The machine was restored before hitting the auction block, although details of what was done were not shared. But it couldn’t have been much since none of the previous owners had even used the prototyping area that was so thoughtfully provided on the top edge of the board. It was sold with period-correct peripherals including a somewhat janky black-and-white security monitor, an original cassette tape interface, and a homebrew power supply. Sadly, there’s no word who bought the machine – it was an anonymous purchase.

Hackers, check your scrap bins. Anything hanging out there that might be worth six figures in a few decades? It’s unlikely, but if you get lucky, hacking just might turn into your retirement plan.

Thanks to [my wife] for the tip on this one.

Microsoft Releases Crown Jewels — From 1982!

October 1, 2018 by 45 Comments

If you look back 30 or so years ago, it wasn’t clear what was going to happen with personal computers. One thing most people would have bet on, though, was that CP/M — the operating system from Digital Research — would keep growing and power whatever new machines were available. Except it didn’t. MS-DOS took over the word and led — eventually — to the huge number of Windows computers we know today. Microsoft has released the source code to MS-DOS 1.25 and 2.0 on GitHub.

Microsoft — then another fledgling computer company — had written some BASIC interpreters and wanted in on the operating system space. They paid the princely sum of $75,000 to Seattle Computer Products for something called QDOS written by [Tim Paterson]. Rebranded as MS-DOS, the first version appeared in late 1981 and version 1.25 was out about a year later.

While you might not think having MS-DOS source code is a big deal, there’s still a lot of life left in DOS and it is also interesting from an educational and historical perspective. If you don’t want to read x86 assembly language, there’s also the BASIC source for the samples (paradoxically, in the bin subdirectory) along with compiled COM files for old friends like EDLIN and DEBUG.

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A Nibble And A Half Of Wooden Bits

September 25, 2018 by 8 Comments

If you are familiar with binary, what would you need to teach someone who only knows decimal? If you do not know how to count in binary, let us know if the video below the break helps you understand how the base-2 number system works. If learning or counting binary is not what you are interested in, maybe you can appreciate the mechanics involved with making a counter that cycles through all the ones and zeros (links to the video shown below). The mechanism is simple enough. A lever at the corner of each “1” panel is attached off-center, so it hangs when it is upside-down, then falls to the side when it is upright, so it can swivel the adjacent panel.

Perhaps this is a desktop bauble to show off your adeptness at carpentry, or skills with a laser cutter, or 3D printer. No matter what it is made out of, it will not help you get any work done unless you are a teacher who wants to demonstrate the discrete nature of binary. If wood and bits are up your alley, we have a gorgeous binary driftwood clock to feast your eyes on. Meanwhile if analog methods of working digital numbers suit you, we have binary math performed with paper models.

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C64 Keyboard Helps Keep The Memory Alive

September 20, 2018 by 11 Comments

To say that the Commodore 64 was an important milestone in the history of personal computing is probably a bit of an understatement. For a decent chunk of the 1980s, it was the home computer, with some estimates putting the total number of them sold as high as 17 million. For hackers of a certain age, there’s a fairly good chance that the C64 holds a special spot in their childhood; perhaps even setting them on a trajectory they followed for the rest of their lives.

At the risk of showing his age, [Clicky Steve] writes in to tell us about the important role the C64 played in his childhood. He received it as a gift on his fifth birthday from his parents, and fondly remembers the hours he and his grandfather spent with a mail order book learning how to program it. He credits these memories with getting him interested in technology and electronic music. In an effort to keep himself connected to those early memories, he decided to build a modern keyboard with C64 keycaps.

As you might expect, the process started with [Steve] harvesting the caps from a real Commodore, in fact, the very same computer he received as a child. While the purists might shed a tear that the original machine was sacrificed to build this new keyboard, he does note that his C64 had seen better days.

Of course, you can’t just pull the caps off of C64 and stick them on a modern keyboard. [Steve] found the STLs for a 3D printable C64 to Cherry MX adapter on GitHub, and had 80 of them professionally printed as he doesn’t have access to an SLS printer. He reports the design works well, but that non-destructively removing the adapters from the caps once they are pressed into place probably isn’t going to happen; something to keep in mind for others who might be considering sacrificing their personal C64 for the project.

[Steve] installed the caps on a Preonic mechanical keyboard, which worked out fairly well, though he had to get creative with the layout as the C64 caps didn’t really lend themselves to the keyboard’s ortholinear layout. He does mention that switches a bit heavier than the Cherry MX Whites he selected would probably be ideal, but overall he’s extremely happy with his functional tribute to his grandfather.

If you’re more of a purist, you can always adapt the C64 keyboard directly to USB. Or go in the complete opposite direction and put a Raspberry Pi into a C64 carcass.

It’s The Web, Basically

September 17, 2018 by 43 Comments

If you are of a certain age, you probably learned to program in Basic. Even if you aren’t, a lot of microcontroller hobbyists got started on the Basic Stamp, and there are plenty of other places where to venerable language still hides out. But if you want to write cool browser applications, you have to write JavaScript, right? Google will now let you code your web pages in Basic. Known as WWWBasic, this is — of course — a Javascript hack that you can load remotely into a web page and then have your page use Basic for customization. You can even import the thing into Node.js and use Basic inside your JavaScript, although it is hard to think of why you’d want to.

According to the project’s documentation — which is pretty sparse so far, we’re afraid — the Basic program is compiled into JavaScript on page load. There are a few examples, so you can generally pick up what’s available to use. There are graphics, the ability to read a keyboard key, and a way to handle the mouse.

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