iiinova — where your digital self keeps evolving

techav @techav.net · 29/09/2026

I gave in to a little self-indulgent nostalgia and bought an iPod Nano just like the one I had new twenty years ago. techav.net/post/8291009...

Black first-generation iPod Nano. The iPod is powered on and displaying the main menu.

000

techav @techav.net · 25/08/2026

Some lessons have to be learned multiple times before they stick. Once again series termination resistors save the day. techav.net/post/8259301...

A protoboard with a neat line of resistors inserted between the Wrap030 main board and one of the main bus ribbon cables.

000

techav @techav.net · 18/08/2026

I thought I had a clever minimal interrupt request circuit for Wrap030, but it turns out I had overlooked a few details. Time for more bodges! techav.net/post/8252959...

New interrupt priority encoder circuit for Wrap030

Colorful bodge wires on the back of the Wrap030 main board, necessary for receiving and handling interrupt request signals.

000

techav @techav.net · 11/08/2026

I finally set about trying to address a significant omission from the 8-port serial card I build for Wrap030: interrupt support. techav.net/post/8246617...

Wrap030 8-port serial card with a bundle of tiny bodge wires soldered directly to fine-pitch QFP pins. The bodge wires are held down with polyimide tape to help keep them from being pulled loose.

010

techav @techav.net · 18/06/2026

Something a little different — I went down a bit of a rabbit hole this week. It started with trying to find the source of this beautiful illustration of IBM computer hardware from the 60s and resulted in hours scrolling through the work of designer Paul Rand. techav.net/post/8197694...

Scan of the centerfold of "Color in the Workplace", a document for IBM by designer Paul Rand. The spread has four rows of illustrations of various IBM computer components, demonstrating color combinations available for purchase.

020

techav @techav.net · 09/06/2026

I finally got around to replacing the batteries in two of my terminals. Luckily there was only a little leaking battery corrosion on one of them, and it only exploded a little while I was desoldering! techav.net/post/8189540...

Wyse WY-55 terminal main board with soldered-in battery.

Esprit Opus2 terminal logic board with leaking soldered-in battery and corroded chip leads

030

techav @techav.net · 26/05/2026

I've finally sorted through the problems that were preventing my new PikaPC host card from booting into forth — just in time for VCF Southwest! techav.net/post/8176857...

A photograph of the initial functional PikaPC phase 2 setup. Four PCBs are plugged into a backplane (from back to front): host, video, power, and protoboard. Logic analyzer probes are attached to the protoboard card on front.

010

techav @techav.net · 22/05/2026

I've been struggling to bring up the phase 2 modular PikaPC system. I had high hopes for a revised PPC403 host card, but so far I've had no luck. But that doesn't mean I've made no progress on the project. techav.net/post/8173233...

PikaPC phase 2 modular system in a minimal configuration with just host card and power card on a backplane. The host card is wired to a logic analyzer which can be seen running in the background

010

techav @techav.net · 07/05/2026

I've decided to make my old PowerMac G4 (Sawtooth 450MHz) useful again by installing a recent release of NetBSD and using it as a PowerPC build server. It runs surprisingly well for an OS that is 25 years newer than the hardware. techav.net/post/8159644...

screenshot of a terminal showing neofetch output running on a 1999 model PowerMac G4. NetBSD 9.4 macppc; uptime 6 minutes; 5 packages; 'sh' shell; [PPC] 7400 rev 1 CPU, 323MiB of 2048MiB memory in use.

040

techav @techav.net · 28/04/2026

I finally have video working reliably using S3 Trio64V+ on PikaPC, my PowerPC homebrew computer. techav.net/post/8151490...

$Close zoom image of the Mandelbrot fractal set rendered on PikaPC and displayed via S3 Trio64V+.$

000

techav @techav.net · 21/04/2026

I successfully wrote a fixed-point Mandelbrot renderer in C to run on PikaPC, but it called attention to a problem I had overlooked. techav.net/post/8145149...

000

techav @techav.net · 14/04/2026

I've finally managed to output video with the S3 Trio64V+ graphics chip on PikaPC, my PowerPC homebrew computer. It's not perfect, but for now it's good enough to keep moving forward. techav.net/post/8138806...

$Grayscale render of the Mandelbrot fractal set created using PikaPC homebrew computer and an S3 Trio64V+ graphics chip.$

000

techav @techav.net · 07/04/2026

Nothing beats actually using the right tool for the job. I've just started down the path of learning to use a proper logic analyzer. In a single capture it found a problem I had spent over a week trying to track down. techav.net/post/8132465...

A mess of 40 test leads attached to the PikaPC protoboard card. There are so many test leads, the PikaPC prototype main board is nearly completely obscured.

A logic analyzer capture of a bus transaction on the PikaPC new bus. The capture display for the AD bus indicates an address of 0x1c3, instead of the expected 0x3c3.

081

techav @techav.net · 02/04/2026

I've been bouncing around on my PikaPC project, but I am still making progress. techav.net/post/8127973...

The new modular PikaPC, with power supply card, protoboard card, DRAM card, and host card plugged into the backplane.

031

techav @techav.net · 24/03/2026

I built a quick test card to help me debug my new bus control logic. techav.net/post/8119780...

000

techav @techav.net · 17/02/2026

This weekend I dropped by my local library and learned how to use a new tool. Walked out with a big pile of custom stickers to hand out this year at VCFSW. techav.net/post/8088109...

Photograph of a table in a library makerspace. Piles of newly-minted stickers are in the foreground. In the background, a Cricut device is busy cutting more stickers.

010

techav @techav.net · 13/02/2026

I currently have the same problem. Sure there is technically a cheaper shipping option, but add on the tariffs on delivery and unspecified handling fees and processing delays and ...

Invoice summary for PikaPC phase 2 PCBs. Merchandise total for 5 designs: $24. Shipping estimate: $55.90. Tariffs: $10.80. Grand total: $90.70.

110

techav @techav.net · 21/12/2025

Wire wrap is great because it can be undone by just twisting the opposite direction. But the layers of wires add up quickly and it can be difficult to fish out a wire to remove it.

Wire-side of the PikaPC homebrew computer main board with several thin wires removed from their posts but currently trapped under all of the wires that were placed after they were originally installed.

010

techav @techav.net · 20/06/2025

VCF Southwest 2025 is officially open! I am set up at the front of the main exhibit hall with my Wrap030 homebrew computer project.

010

techav @techav.net · 26/04/2025

A whole new world of capabilities just opened up for my 68030 computer.

Serial terminal output from "Wrap030", a 68030 homebrew computer, showing the startup sequence and booting a test program from disk. The test program is initializing a hardware timer, which is triggering an interrupt (IRQ 4). The test program is acknowledging the interrupt, returning to the main loop, and resetting the timer.

011

techav @techav.net · 12/04/2025

Manually mapping out signal timing & propagation delays to 1ns resolution for planning a DRAM interface for a MC68030 running at 25MHz.

Photograph of a page in a graph paper spiral notebook showing hand-drawn signal flow diagram. The homebrew computer it will run on can be seen in the background.

020

techav @techav.net · 11/04/2025

Every computer needs a good ASCII art banner that prints out on startup. ... Even if that's currently about all it can do.

071

techav @techav.net · 07/04/2025

Trying to debug a stubborn logic bug with my 68030 homebrew stack. It looks like an Address Error exception, but that doesn't make much sense. Really tough to figure out with only 16 logic analyzer channels.

A mess of rainbow-colored wires and logic analyzer probes attached to a sparsely-populated printed circuit board.

000