There are some Philips PM9547 and Philips PM9547G items on ebay.
Nobody really know what they for, so i bought one (PM9547G) and checked what inside.
The enclosure made of alu, 173x100mm PCB can be placed inside,
~32mm component space between enclosure top side and PCB.
On the PCB there are some TTL ic's, two GPIB bus driver (75160 and 75161), two comparators,
4 optocouplers and mask progammed PCF84C41P / 038.
It is 8048 almost instruction compatible µC, the ROM can't be dumped.
Other components are on the picture.
It seems to be kind of GPIB <-> two i/o line optoisolated controller.
VCC comes over the "Remote control" port, i think 24V AC and 5V DC.
As the µC can't be dumped no idea what the code inside is doing and
probably no real chance to re-use it for whatever.
(i was hoping to find inside upd7210 or MC68488 as GPIB controller, anyway)
Haven't checked but i guess the older version PM9547 should be similar
to PM9547G from this "review"
The whole thing not really worth the 20+USD
EDIT: as we have now the manual, this I²C->GPIB converter can be used in other DIY projects.