A PC Engine To TurboGrafx-16 Converter

October 10, 2014 by Brian Benchoff 23 Comments

The PC Engine was pretty popular in Japan, but only the coolest kids in America had the US edition, the TurboGrafx16. These two systems weren’t exactly the same; the TurboGrafx-16’s data bus was flipped so the games were made to be incompatible, and the US games have a region lockout. [Kaz] looked at the existing hacks for running Japanese games on US systems, and every single one of them required modding a console. Thinking he could do better, he came up with the PC-Henshin, an adapter and CPLD that allows Japanese game to run on US consoles.

To take care of the mixed up lines on the PC card connector between the US and Japanese variants, a few adapter cards are available. That’s great, but they only solve one part of the compatibility problem. The region lockout routine found on nearly every American title mean PC Engine consoles can’t run TurboGrafx-16 games. [Kaz] used a small, cheap CPLD to read the data bus, patch everything as it is read out, and turns a Japanese console into something that can play American games.

Video below.

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The Cassette MP3 Player

October 9, 2014 by Brian Benchoff 34 Comments

1994 was twenty years ago. There are people eligible to vote who vaguely remember only one Bush presidency. You can have a conversation with someone born after the millennium, and they think a 3.5 inch disk is called a save icon. Starting to feel old? Don’t worry, all the trinkets of your youth have now become shells for MP3 players, the cassette tape included.

[Britt] is aware you can pick up one of these cassette tape MP3 players through the usual channels, but she wanted her build to be a little different. She’s using ar real, vintage cassette tape for starters, and from the outside, looks pretty much like any other cassette tape: there’s a thin strip of tape at the bottom, and the clear plastic window shows the tape is at the beginning of side A.

Outside appearances are just that; inside, there is a small, repurposed MP3 player, with tact switches wired up to the old buttons, actuated by moving the spools back and forth. Yes, you actually play, pause, rewind and fast forward by sticking a pencil in the spool and moving it back and forth. Amazing.

It’s a great build, and considering both cassette tapes and cheap MP3 players can be found in the trash these days, it’s something that should be hard to replicate.

CP/M Source Code Released

October 6, 2014 by Adam Fabio 51 Comments

To celebrate the 40th anniversary of CP/M, the Computer History Museum has released a package containing early source code for several versions of CP/M. Originally designed by [Gary Kildall] in 1973, Control Program for Microcomputers (CP/M) is an early operating system for microprocessor based computers. The OS was originally written for the Intel Intellec 8, an Intel 8008 based computer. Since it was on an Intel machine, CP/M was written in PL/M (Programming Language for Microcomputers), a language [Kildall] had previously developed for Intel .

CP/M pioneered the idea of a ROM based Basic Input Output/System (BIOS) for commonly used routines on a given computer. The use of BIOS made CP/M easy to port. Eventually it was ported to thousands of different machines and architectures, including the Altair, IMSAI 8080, C-64, and C-128 and Apple II systems.

Gary and his company Digital Research, were one of the top contenders for the operating system on IBM’s new personal computer. Ultimately, Microsoft got the job by purchasing 86-DOS from Seattle Computer Products. Somewhat ironically, 86-DOS itself was written based on the CP/M Application Programming interface (API).

The source itself is an amazing trip back in time. Included are portions of CP/M 1.1, 1.3, 1.4, and 2.0. Portions of CP/M have been released previously. As with the previous files, this version includes modifications performed by z80-pack author [Udo Munk] in 2007. Version 1.3 is especially interesting as it is primarily scanned copies of the CP/M source code.

If you’re into vintage computing, and know how important CP/M was to the early days of personal computers, check out the CP/M source. If you find any interesting or clever bits of code, be sure let us know about it in the comments.

[Image Source: CulturaInformatica]

Hackaday 10th Anniversary: Quinn Dunki And Veronica

October 5, 2014 by Brian Benchoff 19 Comments

In case you haven’t been reading Hackaday for the last few weeks, we just had an amazing 10th anniversary party in Pasadena this weekend, full of workshops, talks, and a party that reportedly went until four in the morning. One of the amazing hackers we invited to give a talk was [Quinn Dunki], creator of Veronica, the modern 6502 computer stuffed inside an old radio.

We first saw Veronica a few years ago, but [Quinn] figures she’s been building her computer for about five years now. She’s a software developer by trade that decided one day to dip her toes into the murky seas of hardware development and build a computer from the ground up. She chose the 6502 as the brains of her contraption, laid out everything on single-sided boards etched in a kitchen, and connected everything with a backplane. Right now it has a USB keyboard, (technically a PS/2 keyboard with a USB plug), NES controllers, a VGA display, and a monitor and Pong in ROM. [Quinn]’s goal was to build a computer that could program itself, and after five years, she’s accomplished that goal.

[Quinn] admits her software background was responsible for a few of her admittedly bad design choices; the VGA is generated by an ATMega microcontroller, working under the theory that if she could clock the micro fast enough, she could do VGA. She now believes an FPGA would have been a better choice for video output, but now that the video circuit is done, she probably won’t revisit that problem.

There is one thing missing from Veronica, and something that [Quinn] will be working on in the future: mass storage. Right now every program Veronica can run is either stored in ROM or entered via the keyboard. A hard drive is the next problem to solve, either with an SD card, or a Compact Flash or IDE hard drive.

Split Flap Display: If You Can’t Find It, Built It

October 4, 2014 by Mike Szczys 18 Comments

It’s pretty hard to deny that split-flap displays are incredibly awesome. This one has been a long time coming, and it’s not a refab or surplus build. [Tom] fabricated these beautiful alpha-numeric split flaps from scratch.

Having recently seen an alarm-clock split flap hack just a week or so ago we found ourselves wondering where in the world people manage to find this type of awesome mechanical hardware. If you can’t get it out of grampa’s attic, the next best thing is to build it from the ground up.

This was not a build to be taken lightly. [Tom] started years ago, and part way into the project we looked at some of the control hardware for the installation. Make sure that you dig deep into his blog posts. It’s the only way you’ll put together the whole picture of how he ended up with each belt and stepper motor driven character module.

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Sine Waves, Squares Waves, And The Occasional FFT

October 1, 2014 by Bil Herd 35 Comments

I became aware of harmonics and the sound of different shaped waveforms early in my electronics career (mid 1970’s) as I was an avid fan of [Emerson Lake and Palmer], [Pink Floyd], [Yes], and the list goes on. I knew every note of [Karn Evil 9] and could hear the sweeping filters and the fundamental wave shapes underneath it.

I remember coming to the understanding that a square wave, which is a collection of fundamental and (odd) harmonics frequencies, could then be used to give an indication of frequency response. If the high frequencies were missing the sharp edges of the square wave would round off. The opposite was then true, if the low frequencies were missing the square wave couldn’t “hold” its value and the top plateau would start to sag.

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A Nixie Clock With Neon Bulb Logic

September 29, 2014 by Brian Benchoff 27 Comments

This is an oldie, but oh, man is this ever good. It’s a Nixie clock made without a microcontroller. In fact, there aren’t any logic chips in this circuit, either. As far as we can tell, the logic in this clock is made with resistors, diodes, caps, and neon tubes.

The design of this is covered in the creator’s webpage. This clock was inspired by a few circuits found in a 1967 book Electronic Counting Circuits by J.B. Dance. The theory of these circuits rely on the different voltages required to light a neon lamp (the striking voltage) versus the voltage required to stay lit (the maintaining voltage). If you’re exceptionally clever with some diodes and resistors, you can create a counting circuit with these lamps, and since it’s pretty easy to get the mains frequency, a neon logic clock starts looking like a relatively easy project.

This clock, like a lot of the author’s other work, is built dead bug style, and everything looks phenomenal. It looks like this clock is mounted to a plastic plate; a good thing, because something of this size would be very, very fragile.

Video below, thanks [jp] for sending this one in.

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