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- From: pbe@eddie.bs.open.de (Paul Blinzer)
- Newsgroups: comp.os.os2.misc
- Subject: Re: un:com cards with irq
- Message-ID: <PBE.92Aug17232719@eddie.bs.open.de>
- Date: 17 Aug 92 23:27:23 GMT
- References: <1992Aug14.1480.25001@dosgate>
- Sender: pbe@eddie.bs.open.de (Paul Blinzer)
- Reply-To: pbe@eddie.bs.open.de
- Distribution: comp
- Organization: home
- Lines: 52
- In-Reply-To: robert.fielder@canrem.com's message of 14 Aug 92 19:29:25 GMT
-
- In article <1992Aug14.1480.25001@dosgate> robert.fielder@canrem.com (robert fielder) writes:
-
- > KURT KLINGBEIL said:
- > KK>Is there such a thing ? I'm not talking about the multi $100, 4-or-8 port
- > KK>proprietary jobs that require special drivers, and are usually used for
- > KK>multi-user systems. I mean a regular rinkeydink COM card with a '16-bit'
- > KK>card edge that allows jumpering the IRQ up into the 9-15 region...
- > Kurt:
- > [some stuff deleted]
- If you don't mind to use a soldering iron, there's a simple method to add at
- least two more ports to the normally usable COM1 and COM2. All you need is a
- standard (and cheap !) multi I/O-card with a 16-bit wide connector (those
- thingies with two serial ports, parallel port, IDE connector and the like
- on it) and some isolated thin wire. The serial ports of the multi I/O-card
- _must_ be configurable as COM3 and COM4 and _must_ have all contact fingers at
- the at-extension connector (the shorter one of the two pcb connectors). If you
- are in luck, you already have one of those cards within your computer case. You
- then need an additional serial card to get the COM1 and COM2 ports back.
- Before you begin, configure all your I/O cards accordingly to avoid double
- addressing.
- Just figure out the pins B24 and B25 on the bus connector of the card. These
- are the pins for IRQ4 and IRQ3 (used for the serial hardware interrupts of COM1
- and COM2). Just to remember the numbering of slot pins:
-
- :A C
- :----...........------ -------------------
- :B PC-Slot D AT-Extension Slot
- 1 31 1
- Rear
- of
- Computer
-
- Break the tracks leading to these pins with a sharp knive or a small
- screwdriver. Now look for the pins D3 and D4 on the bus connector of the card.
- These are connected to IRQ10 and IRQ11 (normally unused). Solder a wire to
- the former IRQ3 track coming from the interrupt hardware of the serial ports.
- Connect it to the upper part of pin D3. Apply the same procedure to the other
- track and pin D4. Be careful not to flood the whole contact finger with solder.
-
- This was the hardware. Now you only need to tell the system on which interrupts
- to find the new ports. Just insert '(2E8,10) (3E8,11)' as parameters at the
- '\OS2\COM.SYS' entry of CONFIG.SYS. That's all !
- You now have four serial ports, all fully usable within OS/2, DOS and Windows
- emulation (except the port for a serial mouse).
- OK, I admit it's a real hardware hack (although a small one :-) ). But it works
- and it's usable without any additional driver and it's much cheaper than all
- these high-priced supersonic serial cards you speak of.
- --
- ----------------------------------------------------
- | |- - - - -| | Paul Blinzer
- | | HI | | pbe@eddie.bs.open.de
- | | THERE ! | | Kreuzkampstr. 32, W-3300 Braunschweig
-