A software only solution to the vexing beagle bone black PHY issue


Josh Levine has a nice write-up about a software only workaround for the Beagle Bone Black PHY issue:

Sometimes the Ethernet port on a Beagle Bone Black does not work on power up. It takes either a physical reset button press or a power cycle to fix it. This problem affects all BBB’s and until now could only be solved with hardware hacks.

The final official word from TI on this problem:
“There is no solution for this on the BB Black“

Full details at josh.com.

Emulating a hardware ROM in real time with an STM32F4



ROM emulation using an STM32F4:

I remember reading dhole’s  Emulating a GameBoy Cartridge with an STM32F4 some time ago thinking that it had a lot of applications with respect to old computers. In that article  a STM32F4 microcontroller  ‘pretends to be a ROM chip for a gameboy’. At the start of a bus cycle, an interrupt is triggered in the STM32F4, it then reads the address bus of the gameboy’s 6502, checks the gameboy’s read/write line(s) and pulls data from its internal Flash and presents it onto the data bus long enough for the gameboy to read it, then tristates the databus. There are no wait states. It does this all within the 1000ns of the 1MHz Gameboy CPU clock. For all intensive purposes the gameboy thinks it has a real rom chip attached.

Full details at Kernelcrash.com .

Raspberry Pi virtual floppy for ISA (PC XT/AT) computers


Dr. Scott M. Baker wrote an article detailing how he turned a Raspberry Pi into a virtual storage device for ISA bus computers:

I’m tired of carrying compact flash cards and/or floppies back and forth to my XT computer. I like to do development at my desk using my modern windows PC. While I can certainly use a KVM switch to interact with the retro computer from my Windows desktop, it would be a lot more convenient if I could also have a shared filesystem. There are several alternatives, from serial port solutions, to network adapters. However, I wanted something that would emulate a simple disk device, like a floppy drive, something I could even boot off of, so I implemented a virtual floppy served from a Raspberry pi.

See the full post on his blog here.

Check out the video after the break.

Desoldering station


Stynus writes:

Some time ago I bought a lot of Weller soldering irons at an auction for cheap. Between these where a few DSX 80 de-soldering irons.
I also had an old Weller IG101 solder station (bought earlyer from another hobbyist), unfortunately I had no iron for this one and the DSX 80 could not be connected to this one. Time to convert the IG101 to newer standards.

More details at ElektronicaStynus homepage.

Check out the video after the break.

AtPack: Atmel Pack parser, visualizer and fuse calculator



AtPack – Atmel Pack parser, visualizer and fuse calculator from Vagrearg:

Looking for an up-to-date fuse-calculator for the Atmel(*) AVR chips has been something of a long search. There are several online versions, but they have not been updated to the new chips (like the ATmega328PB).
When you have got an itch, you simply scratch it… Don’t you?
Well, I did, and it resulted in an analysis of the Atmel Pack format, which can be freely downloaded under an Apache 2.0 license. The AtPacks contain a master XML file with device lists and links to each device’s XML file, which in turn describes the entire chip. The format is not that hard to understand and can be easily mangled into something useful. Then, some crude jQuery hacking and many hours later… you know how that works.

Code is at GitHub and there is an online version.

Via Vagrearg.

Converting a Seeburg 3WA wallbox into a remote for a modern music player


Dr. Scott M. Baker wrote an article detailing how he converted a Seeburg 3WA wallbox into a media player for his homebuilt audio player:

A bit of background. These Wallboxes were used as remotes in diners and other locations back in the 1950s. You put your nickel, dime, or quarter into the Wallbox, which racks up some credits. Then you select the song you want and the Wallbox sends a signal to the Jukebox, which adds your selection to the queue. Soon thereafter your music is playing through the diner. I’m too young to have experienced these in person when they were state of the art, but I do have an appreciation for antique and retro projects.
A new fad is to convert these wallboxes into remotes for your home audio system, be it Sonos or something else. I have my own homebuilt audio system, basically an augmented Pandora player, so my goal was to use the wallbox to control that.

See the full post on his blog here.

Check out the video after the break.

Philips Hue – control anything hack


Fred writes:

To be honest, my recent simple relay hack wasn’t really all that great. It just used the high power constant current output to drive a SSR. It wasn’t ideal, but it worked. I decided that it was worth the effort to track down some more useful outputs and properly detect the desired state of the bulb.
All it took was a little bit of poking around and probing the pins of the SAM R21 microcontroller with an oscilloscope. It wasn’t actually that hard. On the B22 bayonet fitting version of the bulb I found some.

More details on his blog here, 0xFRED.

PS2-TTLserial adapter for RC2014 and MIDI


Dr. Scott M. Baker published a new build:

The original reason for this project is that I wanted to build a standalone RC2014 with keyboard and display. There is an official RC2014 serial keyboard, but I find it a little inconvenient for my big fingers and poor eyesight. I have plenty of old PS/2 keyboards laying around, so I figured I’d rig up a microcontroller to convert the PS/2 keyboard interface into a TTL-level serial interface that could be plugged directly into the RC2014’s serial port.
Along the way, I discovered that the very same circuit would make an interesting project to turn a PS/2 keyboard into a simple MIDI controller. So I adapted the circuit for that purpose as well.

See the full post on his blog.

Check out the video after the break.

Vintage MIDI: Roland MT-32, Roland SC-55, HardMPU, and an Xi 8088

Dr. Scott Baker writes:

In this video, I decided to upgrade my home built PC from AdLib sound to MIDI. I tried out a couple different midi modules, the Roland MT-32 and the Roland SC-55. I learned that I’d need an MPU-401 or compatible ISA interface, and I explored the alternatives, eventually settling on the HardMPU by Ab0tj. Using the HardMPU schematic, I built a board, programmed the microcontroller, and tried out Vintage games on my Xi 8088. I also wrote my own Midi player to play .MID files using MPU-401 intelligent mode.

See the full post on his blog.