Thanks for all the replies, I sort of thought that would be the case,
but you never know.
I think the best suggestion is to buy an old laptop with parallel port.
A desktop card is good, but I'd then have to swap it when I get a new
PC, or hang on to a bulky item for very occasional use.
If the laptop has a _working_ PCMCIA/CardBus/PC Card slot that will also
work (with XP and perhaps Windows 7).
However I just discovered that my old Dell D630 with a PCMCIA slot
actually doesn't work with any cards. The laptop freezes when you insert
a card. This is a well known problem with the D630, at least with older
ones. Yet my old D610 with a PCMCIA slot works just fine with a Koutech
Cardbus to Parallel Port adapter (but it's not needed because the laptop
already has a parallel port) <
http://www.amazon.com/dp/B000MX99KM>.
Dell D series Latitudes also can use a Dell dock which has a real
parallel port if the laptop itself doesn't have one, but it's kind of a
pain to carry that around.
I have some stepper motors that need to be programmed via SPI using the
manufacturer's utility and their parallel port to SPI cable. It would
cost me $163 for their USB to SPI cable with the proper connector that
works with their utility. I was disappointed that the ExpressCard to
Parallel Port adapter didn't work. It's essentially two chips in that
card, a PCIe to USB and a USB to parallel.
However, you can thank me or blame me (partially) for the fact that
parallel ports didn't disappear even longer ago. I attended a meeting in
South Dakota many years ago that Gateway called to discuss Microsoft's
PC98 initiative which would have _forbidden_ legacy ports. If a
manufacturer included the forbidden ports then they would have lost
lucrative discounts on OS purchases. There was push back from computer
and semiconductor manufacturers and Microsoft backed down.