Published on 10 December 2010
I came across the device pictured here recently at Goodwill (a thrift store) for a few bucks. It looked interesting and potentially useful. I hope you enjoy the pictures and ponder as I did who might have built this - it appears to be a TTL-based microcontroller or maybe it's just an interface to something else. There are no markings at all apart from the calibration sticker, and it reveals nothing about the history of this device.
What you see in the pictures is all I know about this device. Since it has no labels or other identification, I suspect it was built by a hobbyist like many of us here. If anybody can shed some light on this device, I'd appreciate it.
Top Panel. Note the Load/Prgm....switch.
Bottom side. No markings but note the quarter-turn fasteners hold the case together.
Side view of the DB-25 interface connector.
The only identification on the enclosure, a calibration sticker.
So the outside is kind of intriguing, but sure doesn't reveal much about what's inside!
Wow, a circuit built on Vectorboard with TTL parts.
Here's a closeup of the board. Many of the chips are 74LS-series which does help put a time-frame on the construction.
Here's the bottom side of the board showing the wire-wrap construction. Imagine making all those connections and not getting anything connected to the wrong pin. Wire-wrap wasn't limited to hobbyists. For many years I used a spectrum analyzer that was all wire-wrap construction. It had 10 or more large boards filled with chips.
Note the wiring aid to keep the pin numbers straight when working from the back.
The inside of the front panel shows some nice assembly details.
I hope you've enjoyed the pictures. Really makes you appreciate the powerful devices we use today, bread boards and cheap circuit boards!