Making Punch Card Programming A Snap

January 6, 2011 by Mike Szczys 47 Comments

About thirty years ago [H. P. Friedrichs] pulled off a hack that greatly improved the process of programming with punch cards. At the time, his school had just two IBM 029 keypunch machines. One of them is shown in the upper right and it uses a keyboard to choose which parts of each card should be punched out. This was time-consuming, and one misplaced keystroke could ruin the card that you were working on. Since you had to sit at the machine and type in your source code these machines were almost always in use.

But wait, the school acquired a dozen of the TRS-80 computers seen in the lower left. They were meant to be used when teaching BASIC, but [HPF] hatched a plan to put them to task for punch card generation. He built his own interface hardware that connected to the expansion port of the new hardware. Using his custom interface a student could create a virtual card deck that could be rearranged and revised to correct mistakes in the source code. The hardware then allows the virtual deck to be dumped in to the punching machine. This broke the bottleneck caused by students sitting at the punch card terminal.

We think that [HPF] sent in this project after seeing the antiquated hardware from that 1970’s calculator. These hacks of yore are a blast to revisit so don’t be afraid to tip us off if you know of a juicy one.

Calc Is High-tech For 1970’s Homebrew

January 1, 2011 by Mike Szczys 20 Comments

Just one look at that banner image and you’ve got to be thinking “that’s old”! This 1970’s era home made calculator used a 4-function calculator IC that was quite advanced for its time. The only problem is that the chip couldn’t do anything other than calcuations, which left it up to the maker of this dinosaur to get the display and keypad working. Circuit boards were made by drawing on copper clad with resist marker. These controlled the VFD digits for the IC’s output and also fed it the user inputs.

[Thanks Brian]

MIT Inspired Impromptu SegStick

December 27, 2010 by Greg R. Jacobs 15 Comments

If many of the readers out there longed for a Segway for Christmas but Santa didn’t bring you one, you are in luck. The aptly named Seg-Stick by [scolton] is a great way for cheap transportation. It uses a broomstick, along with two DeWalt cordless drills to power this bad boy on 6” wheels. Like articles done before on Hack a Day this is an awesome although rudimentary example of the things that can be made with a short amount of time, some determination, and a few power tools. Great job [scolton].

Build A Fusion Reactor In Your Home

December 27, 2010 by Caleb Kraft 55 Comments

At first we were pretty skeptical of this home made fusion reactor instructable. However, we’ve seen home made fusion reactors before, so it is technically possible, we guess. The construction alone is interesting enough to warrant a few moments of looking.

We’re not experts, so pardon us if we can’t tell you exactly what is going on, but we can appreciate the craftsmanship involved with the build. The vacuum chamber specifically is quite nice.

We know that some of our commenters probably have more experience here. Tell us, does this thing look legit?

Upgrading An Old Polaroid Land Camera For 35mm Rolls

December 26, 2010 by Caleb Kraft 19 Comments

Ok, we recognize that this is a bit of an odd upgrade, since many would probably think that a digital upgrade would be more appropriate. However, we found this interesting anyway. [Marker1024] has taken this old Polaroid land camera and modified it to accept a standard 35mm roll. His list of materials may sound fairly MacGyver-ish with foil and sculpey, but his results look to be well done and fairly sturdy. We have to say that the aesthetics of the camera itself are quite appealing and we could see carrying one of these around. As interesting as the writeup is though, we can’t help but wonder what the pictures look like that came out of it!

Tape Delay Made From Recycled Cassette Decks

December 20, 2010 by Joseph Thibodeau 25 Comments

Professional tape delay units are great fun, but often expensive. You’d think that with so many derelict cassette decks filling the world’s dumpsters someone must have figured out a way to make a cheap tape delay… not only in the interest of saving money (sometimes quality is worth paying for) but also in the interest of re-using otherwise wasted resources.

Forosdeelectronica forum user [Dano] has made just such a device from used cassette decks and miscellaneous parts (translated). First he investigated the operation of the playback, erase, and record mechanisms and broke out the tape heads. The playback head is on a plastic rail so that the delay time can be changed, while the record head is fixed. [Dano] encountered some difficulties in ensuring good quality for the recording and erasure, which is an important consideration when working with magnetic tape.

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Update: 6809 Computing

December 15, 2010 by Chris Nelson 26 Comments

[Matt Sarnoff] is designing his own 8-bit computer from scratch. This means not only designing the hardware but also writing his own kernel and custom libraries. Since we last saw this 8-bit machine hes added both video and sound output which has allowed him to start developing some software for his computer (see it play Conways game of life after the break).

Sticking with the retro theme of his computer he uses a TMS9918 chip to output the video and a YM2149 for audio. The YM2149 was the audio chip used in the Atari ST allowing him to play songs generated for that system with a little bit of hacking to account for the fact that the Atari ST ran at 8MHz where his Motorola 6809 only runs at 2MHz.

Via [Retro Thing]

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