Mystery box...

[tmcw]

Recovered a small electronics box at a college dumpster, I was thinking I might be able to use the box for something else, and/or salvage a few parts. Have uploaded a photo of the inside circuit board.

The only label on it is a generic supplier label, "Anachem", which seems to be in the area of biology equipment, though it's probably strictly not a biology device, it might be used in conjunction with one. None of the inputs/outputs have any labels.

"Front" panel has "on/off" switch, 2 LEDs, and two banana plug ports.

"Back" panel has 8-position DIP switch (white block in the photo), and what I presume is the power input.

The board inside has as you can see, a few resistors and capacitors, in addition to 3 variable resistors to the left (blue blocks) and a diode behind a power regulator on the upper-right.

The 4 socketed chips are as follows:

MC14040BCP - 12-Bit Binary Counter
MC14060BCP - 14-Bit Binary Counter and Oscillator
TS27C64A-20CP - 64K (8K x 8) CMOS UV EPROM
ZN428E-8 - 8-BIT LATCHED INPUT D-A CONVERTER

And the power regulator:

LM2940CT-5.0 - 1A Low Dropout Regulator

Anyone know what it might have been used for, or is it fully dependent on what was put on the EPROM? Any clues on the possibilities based on the components used?

[b700029]

Re: Mystery box...

It looks simple enough that if you provide a schematic, it would be much easier to ascertain its function.

Based on the components and the few traces I can see, my guess is that it outputs a time-dependent voltage profile determined by the contents of the PROM (it would be an EPROM if it had a window for erasing.) The DAC output is likely connected to the two sockets on the front, and its input is the data bus of the PROM. The two counters will be connected to the PROM's address bus and used for stepping through the data. The resistors and DIP switch will be used to set the oscillator frequency or possibly the start address in the PROM. The LEDs are for signaling start/end or something like that.

I have no idea what a time-dependent voltage profile of unknown duration can be used for, but that is what this box seems to be designed to generate.