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Are PC Cards (PCMCIA) and ISA bus electronically compatible?

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wjpl

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Oct 23, 2013
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12
Hello,

I would like to connect an ISA sound card to 486 laptop. I couldn't find any information about connecting ISA cards to laptops, so I thought I could construct an adapter by myself. I compared ISA nad PCMCIA pinouts and there a lot of similarities, but does anyone know, if simple 1:1 adapter (I would just make PCB with ISA slot and connect wires to PCMCIA pins) would work? Or would some special integrated circuits be needed in order to make it work?
If anyone has any information about this topic, it would be great (because making an adapter would take time and I wouldn't like to waste it, if it has no chances to work).
 
wjpl said:
Hello,

I would like to connect an ISA sound card to 486 laptop. I couldn't find any information about connecting ISA cards to laptops, so I thought I could construct an adapter by myself. I compared ISA nad PCMCIA pinouts and there a lot of similarities, but does anyone know, if simple 1:1 adapter (I would just make PCB with ISA slot and connect wires to PCMCIA pins) would work? Or would some special integrated circuits be needed in order to make it work?
If anyone has any information about this topic, it would be great (because making an adapter would take time and I wouldn't like to waste it, if it has no chances to work).
Click to expand...

I gotta ask, why not just buy a PCMCIA sound card?

That said, I think there were some commercial expansion chassis units that would do PCMCIA to ISA or PCI, so it's probably possible to build something.
http://www.gl.com/platforms.html#pciexpansion
 
PCMCIA is based on ISA, but it probably isn't 100% directly compatible with it. It was primarily designed as an inexpensive memory interface with mobile devices. General compatibility with things like modems, network adapters, etc. came a bit later.

You'd almost certainly need at minimum some glue logic to make everything happy. More likely, you'd need some bridge chip to make it work.

Like the above poster said, it'd make more sense to get a ready made breakout kit (albeit expensive.) As for getting a PCMCIA sound card, I wouldn't bother. I've seen several over the years and they were all quite dreadful. Not to mention you can't use the internal speakers on the laptop if it has any.
 
GiGaBiTe said:
As for getting a PCMCIA sound card, I wouldn't bother. I've seen several over the years and they were all quite dreadful. Not to mention you can't use the internal speakers on the laptop if it has any.
Click to expand...

Yep. Although the reason I never got one (aside from needing external speakers) was that I never found one at a reasonable price. So instead of a 486 laptop, I went with an early Pentium laptop that had a sound card built-in (Toshiba Satellite 400CDT, if you wanted to know what it is; I chose that one specifically because it has a 640x480 active-matrix display, which is great for DOS games in an era when laptops didn't have built-in scaling hardware for lower resolution graphics modes). I will say that I've ran into a problem with one game on that laptop that, I guess, handles the keyboard differently than others. Space Chase 3 (or just Space Chase, but somehow I only had part 3) will work briefly, then your character will stop responding. This doesn't happen if you hook up a gameport joystick to the docking station and control with that, but that takes away a lot of the portability.
 
I used to use a PCMCIA Sound card/CD-ROM combo from Altec Lansing back in the mid 90's on my 486-100mhz laptop, and I was quite pleased with it, though I didn't do much DOS gaming on it (my desktop was used for gaming), and its quite possible it may not have been much good in DOS, as DOS PCMCIA support was pretty poor, but this would be the same problem with a PCMCIA to ISA bridge and ISA sound card, you would still need DOS PCMCIA support, it would not be NATIVE ISA, it would suffer from many of the same shortcomings as a PCMCIA native sound card. I used my PCMCIA setup for a few months on Windows 3.11, but Windows 95 was released shortly after I got the unit, and most of my use of it was under Win95, and it worked as well as any sound blaster or compatible within Windows, never a hiccup.

Back to ISA on laptops, you may want to look into if your laptop had a "docking station" provision, many of the time did, I have had Compaq laptops/portables from 286 all the way up to Pentium MMX that had ISA or PCI slots in their docking stations, and these were not bridged slots, but REAL slots connected to the laptop via a high pin count docking port. I have used sound cards, video cards, and even USB cards, all manner of devices will work in these "docking stations" since they are not bridged or emulated slots.
 
I can't say that this item even EXISTS, as you would need to not only have an outboard ISA backplane, but a PS for it too, as well as the "adapter".

The cost would probably be prohibitive, as you are now looking at an item that (even if it was made) would not sell very well, so it would be sold at a premium...

There are ISA->PCMCIA, but that's the other way round (and even those are/were costly).

I think I'd stick with a good PCMCIA/speaker-amp combo, and call it a day!

I'm just sayin'...

gwk
 
OK, so it looks that it might be more complicated than I thought...

I was just planning to do something like this:

adapter.jpg

solder appropriate pins and make a simple adapter. But after reviewing pinouts, it looks like all data pins are the same, but there are differences related with IRQ and DMA pins (they are missing in PC card). Of course not all ISA cards use all available pins, but I'm not sure it would work.
View attachment isa_pinout.pdf - I compared ISA and PC card here

But I found out something more interesting - it seems that PCI and Cardbus pinouts are almost identical (only 5 pins are different and I dont know if they are necessary), also i have read somewhere that its protocol is identical with PCI, maybe I should try creating such adapter, unfortunately it would work only with Pentium-based laptops.
View attachment cardbus_pci_pins.pdf I compared PCI and Cardbus here

I heard that Express Card is exactly PCI-E 1X plus one USB port, so maybe Cardbus also is compatible with PCI.
 
Well, regardless of signal, you will have to deal, at the very least, with issues of power to the ISA/PCI card.

The laptop, for sure, will NOT provide enough current, let alone all diff voltages. Remember, the PCMCIA/CARDBUS slots RARELY provide more than 500ma, and a typical ISA or PCI card might need 1-3 AMPS! (1000ma-3000ma)

gwk
 
Yes, I know that, but I already managed to built a miniature DC/DC switching power supply which gives all AT standard voltages, and I can use it with external power brick to power up an extension card, at least for testing purposes. Actually I know that PCI to cardbus adapters exist (I saw one that seemed to have no external electronics, but I can't find it anymore; i can find now only larger adapters, which have some controlling chips, but they can handle two or three PCI cards). I might try to construct such adapter one day, but it is no longer my priority after I realized that there may be problems. Anyway I will post my efforts here if I will achieve anything.
 
1-3 Amps is a bit much for a sound card - 5V/2.1A are enough to run a 486-100 on PCI mainboard, including Matrox Mystique, CF card and keyboard.

But apparently the +12/-5/-12V rails are not available on PCMCIA.

The biggest problem is the lack of DMA. That rules out the advanced sound cards. You might get away with the Covox-DAC type or an Adlib, but no Soundblaster/GUS.
 
Even if you solved some of the other issues one other issue would be there would be no Card Information Structure (CIS) so no standard Card Service software would would work for the adapter without that. You would have to write some software of your own to configure the socket controller. I haven't looked at the details of that stuff for almost 20 years and forget the details now.
 
The Creative site list several legacy SB cards (needing all three rails), where +12 alone takes min 500ma..(you are already at most sockets limit, right there), so I'm pretty sure that you are going to approach 1AMP at least, with an onboard amplifier. --- It would depend on vagaries of the model, but if you add in 2 sticks of RAM for the samplers, you'll exceed that by some too...

And the specs I looked at were for old boards with minimal amplification (if you add an OPL type processor and amp, they take almost as much current as a stock 8088!)

gwk
 
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