I couldn't find the card by scanning visually the pictures in TH99.
The chips on the card provide a total of 384kB RAM (9x41256=256kB plus parity, 4x21464+2x4164=2x64kB plus parity), the larger chips are from top down: FDD controller, serial controller, printer/parallel controller. Cannot say anything about the DIPs. It's similar to a few memory/IO cards made by Kouwell but doesn't match any of them.

Based on my experience with similar cards, it's probably meant for PC or XT to backfill main memory on machines with less than 640kB RAM, and provide IO and floppy ports. I have a card with similar functions, a Diamond Flower MF-100 https://stason.org/TULARC/pc/io-cards/C-D/DIA … 0-MF-100-A.html the manual for which was uploaded to http://minuszerodegrees.net/manuals.htm#DFI It has jumper settings for that card, and while they won't match the DIP settings on yours it may give you an idea about what to expect. Mine came with a floppy with utilities (ramdisk utility, print spooler etc).

Thanks, I'll take a look. This card is confusing because it uses 3 different kinds of memory chip. I don't know why the designers did this.

ETA: From what I can determine, there are four memory banks, two of 256 KiB and two of 64 KiB, for a total of 640 KiB

• Bank 0: 8+1P DIP-16 soldered to board (256 KiB + 32 KiB parity)
• Bank 1: 8+1P DIP-16 socketed (256 KiB + 32 KiB parity)
• Bank 2: 2 DIP-18 + 1P DIP-16 socketed (64 KiB + 8 KiB parity)
• Bank 3: 2 DIP-18 + 1P DIP-16 socketed (64 KiB + 8 KiB parity)

It is currently configured for 384 KiB as mentioned above, as Bank 1 is unpopulated

I assume that the 6 DIP switches enable/disable (a) the floppy controller, (b) the serial port, (c) the parallel port, (d) memory bank 1, (e) memory bank 2 and (f) memory bank 3. Switch 6 is in the "off" position and all others are "on", so I assume that this is the Bank 1 switch. Absent documentation, everything else will have to be determined by experiment.