Further to my previous question, I am wondering how best to connect an SCM Swapbox "SBI-D2P" (Classic X2) PCMCIA card reader to a modern PC (PCI/PCI Express/SATA/USB). I am aware there are USB PCMCIA readers, and in fact I have one also, but I want to use this Swapbox because it is nice. I am mainly interested in using it for memory cards, but also have hard drives (double size card), Ethernet, Wifi.

Here is the reader (3.5" floppy bay):

enter image description here

The card goes in from the bottom, upwards. The button for ejecting the card is visible in the lower right of the picture.

And here is the ISA card:

Note that I do have the cables, although they are not shown in the pictures.

Two 50-pin cables from the reader to some modern interface. What is the easiest solution?

Edit: I note that new Chinese PCI adapters are available from Ebay for USD 20.

  • 1
    Since PCMCIA is based on the ISA bus, the ISA card just connects the ISA bus to the PCMCIA slots in your 3.5" bay. So this question just resolves to the same question as your previous question: how do you connect an ISA bus device to a modern PC? If you're trying to use this to read CompactFlash memory cards then you'd be better off with getting a modern USB based CompactFlash reader. If you're trying to use other kinds of cards you're probably out of luck and will need a PC with a real ISA bus (or one with PCMCIA/PC card slots).
    – user722
    Jul 11, 2019 at 23:49

1 Answer 1


I think this swapbox could be connected to a more modern machine, but it'd require some soldering work to achieve.

From looking at the connectors on the cable and card reader, it appears to use a pair of 50-pin IDC ribbon cables.

Image of 50-pin IDC ribbon cable

PCMCIA / Cardbus cards have 68 connectors each, however. There doesn't appear to be any duplication of pins (e.g. multiple ground lines), so the manufacturer has managed to squeeze 2x68 wires for the two slots into 2x50 connectors somehow. They might have done this by not duplicating some wires used by both slots (e.g. the 25 address lines).

At the "modern PC" end, PCI adapters for PCMCIA / Cardbus cards were (and are still) commercially available. They tend to be one-card adapters, rather than two-card ones, so you'd need two of them if you wanted to use both of your swapbox's slots.


That leaves the trickier issue of connecting the swapbox to the new adapters. This would probably require making a new, bespoke cable. The swapbox clearly uses a non-standard pinout, so you'd need to reverse-engineer this part first.

Does the swapbox have any chips or active components inside it? It'd be worth opening the cover to have a look first. If the swapbox is just a passive adapter, it would be possible to use continuity test function of a multimeter to work out how each slot's pins are connected to the IDC connectors. It'd be a slow job, but not a complicated one.

Once you know the pinout of the swapbox's IDC connectors, you'd need to come up with a way of connecting it to the PCI adapter. Bare PCMCIA connectors can be bought new, but they're relatively expensive for what they are. I'd suggest using the PCI card as-is, and cannibalising an inexpensive CompactFlash / Microdrive adapter for its PCMCIA connector instead.

PCMCIA adapter for CompactFlash or Microdrive cards

This could be soldered to a ribbon cable leading to the swapbox, using the pinout that you created earlier.

If, on the other hand, the swapbox has some active computer chips inside, connecting a PCI-PCMCIA adapter to the IDC connectors may not work correctly: the PCI-PCMCIA adapter would expect to be connected to a PCMCIA card, not to an intermediate interface chip.

If you're able to remove the swapbox's case and photograph the circuit board inside, it may be possible to give a more definitive answer.

  • @TomasBy The only "easier" solution I can think of would be to use a USB->ISA adapter, as suggested by a comment to your linked question: retrocomputing.stackexchange.com/questions/11001/… , but in this instance "easier" also means "more expensive". I've expanded that comment into an answer over there.
    – Kaz
    Jul 12, 2019 at 7:46

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