Files here are read of the contents of the two PROMs in my counter.
Fluke PM6681/056
circa 2005 from date codes on many chips in the counter.

The PROM chips are two ST M271001-70F1, 32-pin DIP package
1Mbit (128k x 8), 70 nS, UV Erase

This firmware is v1.09
Chips are High and Low so each contains alternate bytes of the firmware.

The readout of the two chips are in the files:
PM6681-v109-L.BIN
and
PM6681-v109-H.BIN

I then merged these two files and the full firmware image is in:
PM6681-v109-Merged.BIN

The GPIB command *IDN? has identification details from this counter:
PHILIPS, PM6681, 0, MAIN V1.09  26 JAN 2001 / GPIB V1.13  26 JAN 2001

The labels on these PROMs are shown here:
chip labels.txt
and
proms labels.jpg

-Rex Allers, KK6MK
