[aprssig] Dual Serial Port PCMCIA card; $50

Mike Yetsko myetsko at insydesw.com
Tue Nov 9 07:48:30 EST 2004

> Since this seems to be a recurring need here:
> http://www.compgeeks.com/details.asp?invtid=CBS2000X-N&cat=CCD

Note closely that this is a "PC CARD", it is NOT a PCMCIA card.  And
actually it looks like a good deal.  Usually they are a LOT more
as they aren't really a high quantity item.

The difference is that PC CARD is actually CardBus, which is
a 'hot swappable' version of PCI, and as such is just like buying and
installing a PCI card with two serial ports.

PCMCIA is a 16-bit 'pc bus' version and has ONE and ONLY ONE
IRQ line, and that line MUST be the one needed.  If that works for you
fine.  You CANNOT install PC CARD cards into PCMCIA and expect
them to work, except in PCMCIA mode.  PCMCIA cards CAN be
inserted into PC CARD slots but then the same 'PCMCIA' rules of
configuration apply.

The only caveat I have here is the ad copy for the site above seems to
skirt the issue as to how the drivers are written...  Hopefully they will
a total 'non-issue'.  But until I actually got my hands on the card, I
hazard a guess.

One key thing with PC CARD.  You do NOT have a 'IRQ' line.  ALL
PCI type cards use PCI Ints on the PCI bus.  This USUALLY is totally
transparent to the user/operator.  A com port is a com port.  But I see
it complained about here all the time from people who don't know what
they are talking about.  If a device is on the PCI bus, it's more than
a 'virtual' device that will 'look like' an old legacy device.  That means
that if you use PROPERLY BEHAVED and (the real key) PROPERLY
WRITTEN software, it cannot tell the difference between old legacy
devices and the latest and greatest virtual device, even if that new
is at the end of a USB cable, on a PC CARD, or even 1000 miles away
across a network.  But a LOT of the HAM code out there is old stuff
that is not written to spec (should I say it was poor?  That's not fair,
a lot was written 'pre spec' for the new stuff) and it just won't work.
not the hardware, it's the SOFTWARE!!!


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