Ditch The IPad; Build A Commodore 64 Tablet

The classic Commodore 64 has had its share of modernizing in the OS department. From its roots starting up a basic prompt, to full high resolution GUI packages like GEOS, to today where [Jim_64] added a tablet like launcher complete with a touch screen interface.

The GUI itself takes advantage of the high resolution graphics of the C-64 that looks similar to iOS, Icons are selected via cursor keys or joystick (what? no light pen?) and launch the various functions they represent. To add to the tablet-like feel of the OS, an off the shelf 3m touch screen panel and its corresponding RS232 interface board were obtained from digikey.

With the panel securely attached to the monitor, XY data from the various finger pokes are sent via serial at a blazing 1200 bps where the program interprets the position. Using the available demo (download sideA and sideB) and off the shelf parts, this should be easy for anyone with a classic C-64 to set up in their own home and have some fun.

Join us after the break for a few demo videos!

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Replacing The CRT In A Vectrex

The Vectrex is a rare beast in the world of retro video games. Introduced in 1982, this was the only video game system to put a monitor right in the console, and it did so for good reason. This was a games system with vector graphics and rotating 3D objects, something that just couldn’t happen on the TV in the family room. A while ago, [John] dug his old Vectrex out of his basement and replaced a faulty logic board. The CRT was still broken, but with a little bit of research and a not-so-ugly kludge, he managed to replace the CRT in a Vectrex.

[John] found someone willing to part with an old CRT online, and after whipping out his credit card, the tube was on his way to his front door. This new tube wasn’t a direct drop in; The original Vectrex had small ears around the edges of the screen that served as mounting points. The new tube had no such ears. Now, a bit of plastic strapping holds the CRT in the chassis. It’s a bit of a kludge, but at least now [John] has a source of Vectrex CRTs.

While the rest of [John]’s repair work didn’t go as well – the Vectrex in question still has all the logic board problems it had when it was taken out of storage. This Vectrex does have a new CRT, and with a bit more work on rehabbing this old machine, it should keep on working for another thirty years.

Whenever you come cross an interesting CRT, make sure you snatch it up. Here’s another offering that uses a tiny screen for some classic MAME action.

Breaking Out A Game Boy Link Cable

[Samuel] is working on one of the most important electronics projects of our generation. He’s building a device for the Game Boy that will allow Pokemon trades between generation II and III. Yes, This means bringing your Charmander from Pokemon Red to your team in Pokemon Ruby, Sapphire, or Emerald. and finally completing the National Dex you’ve been working on for 20 years. Before he gets to designing this system, he first needs to listen in on the Game Boy Link Cable, and that means creating a breakout board.

The Game Boy Link Cable – sometimes inaccurately referred to as the Zelda cable – is a special proprietary connector. The design is well documented, but unlike the Wii Nunchuck controller, there’s no readily available breakout board available for this piece of obsolete technology.

Together with a his friend [David], [Samuel] loaded up a copy of Eagle and designed a board that will fit on a small piece of copper clad FR4. This design was then sent over to a small CNC mill, The traces were machined away, and a sextet of pins were soldered into the holes.

With a breakout board for the Game Boy Link Cable, [Samuel] now has a great platform for peering into the strange and magical world of Pokemon. He’ll be using a Teensy microcontroller for his trading device, and with several similar projects already completed by others around the Internet, the potential for a Gen II to Gen III Pokemon trader is palpable.

The IBM 1401’s Unique Qui-Binary Arithmetic

Old mainframe computers are interesting, especially to those of us who weren’t around to see them in action. We sit with old-timers and listen to their stories of the good ol’ days. They tell us about loading paper tape or giving instructions one at a time with toggle switches and LED output indicators. We hang on every word because its interesting to know how we got to this point in the tech-timeline and we appreciate the patience and insanity it must have taken to soldier on through the “good ol’ days”.

[Ken Shirriff] is making those good ol’ days come alive with a series of articles relating to his work with hardware at the Computer History Museum. His latest installment is an article describing the strange implementation of the IBM 1401’s qui-binary arithmetic. Full disclosure: It has not been confirmed that [Ken] is an “old-timer” however his article doesn’t help the argument that he isn’t.

Ken describes in thorough detail how the IBM 1401 — which was first introduced in 1959 — takes a decimal number as an input and operates on it one BCD digit at a time. Before performing the instruction the BCD number is converted to qui-binary. Qui-binary is represented by 7 bits, 5 qui bits and 2 binary bits: 0000000. The qui portion represents the largest even number contained in the BCD value and the binary portion represents a 1 if the BCD value is odd or a 0 for even. For example if the BCD number is 9 then the Q8 bit and the B1 bit are set resulting in: 1000010.

The qui-binary representation makes for easy error checking since only one qui bit should be set and only one binary bit should be set. [Ken] goes on to explain more complex arithmetic and circuitry within the IBM 1401 in his post.

If you aren’t familiar with [Ken], we covered his reverse engineering of the Sinclair Scientific Calculator, his explanation of the TL431, and of course the core memory repair that is part of his Computer History Museum work.

Thanks for the tip [bobomb].

Tote Boards: The Impressive Engineering Of Horse Gambling

Horse racing has been around since the time of the ancient Greeks. Often called the sport of kings, it was an early platform for making friendly wagers. Over time, private bets among friends gave way to bookmaking, and the odds of winning skewed in favor of a new concept called the “house”.

During the late 1860s, an entrepreneur in Paris named Joseph Oller invented a new form of betting he called pari-mutuel. In this method, bettors wager among themselves instead of against the house. Bets are pooled together and the winnings divided among the bettors. Pari-mutuel betting creates more organic odds than ones given by a profit-driven bookmaker.

Oller’s method caught on quite well. It brought fairness and transparency to betting, which made it even more attractive. It takes a lot of quick calculations to show real-time bet totals and changing odds, and human adding machines presented a bottleneck. In the early 1900s, a man named George Julius would change pari-mutuel technology forever by making an automatic vote-counting machine in his garage.

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Cutest Possible Atari Disk Drive

[rossumur]’s first computer was an Atari 400, and after riding a wave of nostalgia and forgetting the horrible keyboard found in the Atari 400, he decided it was time to miniaturize the venerable Atari 810 disk drive by putting an entire library of Atari games on a single microSD card.

SD cards have been slowly but surely replacing disk drives for just about every old computer system out there. You no longer need 400k disks for your old mac, and your Commodore 64 can run directly off an SD card. The Atari 8-bits have been somewhat forgotten in this movement towards modern solid state storage, and although a solution does exist, this implementation is a pretty pricey piece of hardware.

[rossumur]’s hardware for giving the Atari 8-bit computers an SD card slot is just one chip – an LPC1114 ARM Cortex M0. This, along with an SD card slot, 3.3V regulator, a LED and some caps allows the Atari to talk to SD card and hold the entire 8-bit Atari library on a piece of plastic the size of a fingernail.

Designing a circuit board doesn’t have the street cred it once did, and to give his project a little more pizzazz he chose to emulate the look of the very popular miniaturized Commodore 1541 disk drive with a tiny replica of the Atari 810 disk drive. This enclosure was printed at Shapeways, and with some enamel hobby paint, [rossumur] had a tiny, tiny 810 drive.

While this build does require the sacrifice of a somewhat rare and certainly old Atari SIO cable, it is by far the best solution yet seen for bringing a massive game library to the oft-forgotten Atari 8-bit home computers.

Thanks [lucas] for the tip.

No Pascal, Not A SNOBOL’s Chance. Go Forth!

My article on Fortran, This is Not Your Father’s FORTRAN, brought back a lot of memories about the language. It also reminded me of other languages from my time at college and shortly thereafter, say pre-1978.

At that time there were the three original languages – FORTRAN, LISP, and COBOL. These originals are still used although none make the lists of popular languages. I never did any COBOL but did some work with Pascal, Forth, and SNOBOL which are from that era. Of those, SNOBOL quickly faded but the others are still around. SNOBOL was a text processing language that basically lost out to AWK, PERL, and regular expressions. Given how cryptic regular expressions are it’s amazing another language from that time, APL – A Programming Language, didn’t survive. APL was referred to as a ‘write only language’ because it was often easier to simply rewrite a piece of code than to debug it.

Another language deserving mention is Algol, if only because Pascal is a descendant, along with many modern languages. Algol was always more popular outside the US, probably because everyone there stuck with FORTRAN.

Back then certain books held iconic status, much like [McCracken’s] black FORTRAN IV. In the early 70s, mentioning [Nicolas Wirth] or the yellow book brought to mind Pascal. Similarly, [Griswold, (R. E.)] was SNOBOL and a green book. For some reason, [Griswold’s] two co-authors never were mentioned, unlike the later duo of [Kernighan] & [Ritchie] with their white “The C Programming Language”. Seeing that book years later on an Italian coworker’s bookshelf translated to Italian gave my mind a minor boggling. Join me for a walk down the memory lane that got our programming world to where it is today.

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