What follows is the story of how I fixed not one, but two, different flawed Altera USB Blaster clone devices that never worked correctly after I bought them.
I recently built a few Time Sleuths for HDMI input lag testing. Time Sleuth is a neat little open-source project that allows you to measure the time it takes for your TV or monitor to display an image. The way it works is an Altera/Intel MAX 10 FPGA creates a video signal that is mostly a black screen with some blinking white boxes. It feeds the image off to a TI TFP410 DVI transmitter, and also looks for a pulse on a photodetector. It measures the difference in time between when the white box blinked on and the photodetector saw it, and displays it as a number on its generated video signal with some min/max/average stats. Pretty cool! If you’re not into soldering, you can also buy them fully assembled.
Several months ago, Will from CayMac Vintage reached out to me looking to resurrect my old Mac ROM SIMM programmer project. As a quick summary of that project, it provides a convenient way to program custom 64-pin ROM SIMM modules for vintage Macs from the late ’80s to early ’90s. There are several reasons you might want to do this, including: replacing an original ROM module that has gone bad, disabling the startup RAM test to decrease boot time in systems with a lot of RAM, bbraun’s amazing bootable ROM disk hack, or my startup chime hack. JDW recently made a cool YouTube video explaining custom ROM SIMMs if you’re curious about them. He even included some footage from 2003 of me playing basketball!
I used to make programmer boards and programmable ROM SIMMs and sell them to hobbyists, but it burnt me out. In particular, assembling the boards and the logistics of shipping were not fun to deal with. Thankfully, in 2016, Steve from Big Mess o’ Wires stepped in to take over. He made his own customizations to the programmer and made some really neat improvements to the bootable ROM disk driver. He still sells the Mac ROM-inator II SIMM to this day, but he stopped selling the programmer board. In the meantime, many other players have entered the market with custom ROM SIMMs, but nobody has been making the programmer available to the community, likely due to my non-commercial license on the PCB design.
Will was looking to fill that void. I helped him get going, but we discovered that the AT90USB646 microcontroller that I originally used was hard to find due to the chip shortage. At the time, it was easier to find the AT90USB1286 instead, which is essentially just the exact same chip, but with 128 KB of flash instead of 64 KB of flash.
