With all this discussion, I have my two cents and a question.
Years ago, in MSDOS, with BPQ, I used a modified MS-400 card that
worked perfectly. The mod simply OR's all IRQ requests from the any
of the four 16450's to a single IRQ line. So I had COM 1 with mouse,
COM 2 with CAT, and COM 3 thru COM 6 for kiss radio ports. And I
never used all four, just usually two and used three for a short time.
This mod for the MS 400 has two variants: One diode mod proposed by
Roy Engehausen, AA4RE, and a CMOS IC by someone else later, but the
principle is the same.
When I tried this card with Linux (Slackware 3.3 and kernel 2.0.36)
it did not work properly. My PTC-II became inacessible. Since it
runs in host mode, I put it in ttyS1 as it also does the CAT. ttyS2
runs OK the 2 meters KPC-2. When I wanted to add a second KPC-2,
none of the KPC's worked.
Someone told me that some 2.1.x kernel could share IRQ's, and that
2.0.36 does not.
I mention this because it is very cheap to get even two port cards to
eat a single IRQ line...if it worked OK !! (BPQ did....it is
possible on a PC under MSDOS).
Could someone update/clarify us on this matter ?
Until I get a newer mainboard and cards, I would like to be able
to squeeze the most out of my old, and still functional hardware.
73 de Jose, CO2JA
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Ing. Jose A. Amador | Telf: (537) 20-7814
Depto de Telecomunicaciones | E-Mail: [EMAIL PROTECTED]
ISPJAE |
