Afternoon all,

On the trains at work we have an on-board computer that has a number of interface ports on. One of the cards has a 15 pin female port, similar to a VGA port. To interface with this card we use the parallel port on a laptop. The laptops we use are Dell Latitude D610s and have a parallel port, however the customer has been given a single compatible laptop and is finding it hard to find replacements, they are looking to the future (25 years or so) and struggling to see where they can get laptops with these ports from, especially at a reasonable price.

We have apparently tried a number of USB-to-parallel solutions with no luck. I have been asked to look into expansion cards for laptops as another solution. I've never owned a laptop with expansion slots, and have zero knowledge about them.
- From what I can gather, PCMCIA is now defunct and everything is ExpressCard?
- ExpressCard comes in one of two form factors?
- If I find an ExpressCard that gives me a parallel port, is it likely to work? Basically I know nothing about parallel and don't fully understand if there are fundamental differences in uses.
- I've had a quick look and found one on Maplin and one on Amazon, why is there a £40 difference in price?
- How much longer could I expect ExpressCards to be available for, do you think? I know that we never know what's round the corner, but as far as I knew before looking, expansions slots disappeared a few years ago...

Any and all responses are very welcome. Unfortunately it doesn't look like the company I work for will be doing anything, the project was commissioned a little over two years ago and the customer has only just brought it up at the end of the warranty...

Thanks very much,
Ben

Unfortunately, the interface was probably designed for bit-bashing in DOS at the BIOS level. Most converters you find will be incompatible, even if the software runs quite well in Windows.

It used to be a great IO because you could read and write to all 8 data and 4 or more control lines, and it was at TTL voltages which meant you needed no interface hardware at all.

I have the same problem with an ADC I designed about 10 years ago - it only works on my old 8088 powered laptop I still keep for the job. It doesn't work with any USB adaptors because they mostly emulate a USB printer. It doesn't even work with more recent on-board parallel ports because they aren't compatible at a binary level.

You may have to look at having a custom USB converter and drivers commissioned. It's worth raising this with the manufacturer. They need to provide support.

With regard to ExpressCards, the slot provides for USB and PCIe connections. The cheaper one is probably USB and unlikely to emulate a genuine parallel port. Not enough info to be sure.

The more expensive one states it supports all parallel port modes, so is the most likely to work.

Just remember that no one makes laptops with that slot any more. It's also de-facto obsolete, let alone in another 25 years.

Thanks very much, JJ.



Hmmm, could be an issue
EDIT: Apparently Dell still offer the slots on Vostro , Latitude and Precision laptops - according to the Dell salesman I was just talking to...Though I don't think that's much to go on...

No he's right.

I guess it would have been better to say that the slots aren't fashionable any more. I stand by my guess that you won't find one in 25 years though!

I certainly haven't noticed them in a fair while! My guess was it would be a struggle in the next five years or so. But then again my company will be happy if they can blag that until then, because in 2018 the franchise is up for grabs and we won't be supporting it any more...

No, it isn't - I remember one telling me the computer I'd be ordering had an AGP slot and that DVD drives cost £100 in the shops...