Nibbler 7400 4-bit custom CPU update

Steve at Big Mess o’ Wires posted an update on his Custom 4-Bit CPU: Enough with the vague design talk – here’s the circuit schematic for the Nibbler 4-bit CPU! Click the image to zoom in to a full size view. For simplicity, this version omits some details like bypass capacitors, clock generation, reset circuitry, etc. The […]

Blast from past: Automatic shutdown timer for TVs

Back in the 80s when very few TVs had remotes, let alone automatic shutdown timer, Victor decided to build exactly that for his grandfathers TV. After a set interval an LED turns on indicating that the timer has expired, if a button isn’t pressed within a few seconds the TV is turned off. My grandfather […]

DIY 6502 computer using block transfer engine

Andre Fachat has written a post on his 6502.org blog detailing his DIY 6502 computer build. “I have built a DIY 6502 computer, which is mostly TTL logic only except for 65xx chips and ROMs, but the most TTL-ish part is the blitter: A block transfer engine that DMAs memory area from one location to […]

Workshop Update for July 4th, 2012

UPS package finally corralled, and will be delivered tomorrow. A 74HCT245 will complete a long-delayed final revision of a certain secret prototype. We prepared for tomorrows workshop video on serial port interfacing. We arranged a giveaway for a coming week, and perhaps the first sponsor of the 2012 Open 7400 Competition. Today we continued contacting […]

Workshop Update for June 12th, 2012

Today we renewed websites, including 7400contest.com which is coming up again soon. We patched an SPI speed error in the Bus Pirate binary access mode. We had to cancel the company credit cards because 7 unexpected charges to Blizzard (World of Warcraft) and 4 to iTunes showed up today. In the process of checking the […]

7400 Contest: 24 hours left

Reminder to all those interested in entering their projects into our Open 7400 Logic Competition: Entries must be received by October 21, 2011, 6AM GMT. You only have 24 hours left to send your entry in. Entering Entries can be posted on in our forum, on your personal blog, or even a handy how-to site like Instructables. When you’re […]

Open 7400 Logic Competition: Only two days left to enter!

Reminder to all those interested in entering their projects into our Open 7400 Logic Competition: You only have two days left to send your entry in. Entering Entries can be posted on in our forum, on your personal blog, or even a handy how-to site like Instructables. When you’re ready, please submit a link to […]

7400 competition entry: SPI LCD backpack

Stephen added his entry in the Open 7400 Logic competition, he made a LCD backpack that uses the SPI interface. Using two 74LS595 serial to parallel shift registers connected in series, he successfully sends data to the 16×2 LCD and adjusts the backlight brightness, by sending 2 bytes over the SPI. The first byte to be sent is displayed on the LCD, and […]