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- Newsgroups: comp.sys.amiga.emulations
- Subject: Re: My Entire Bridgeboard
- From: stewart.hunt@canrem.com (Stewart Hunt)
- Path: canrem.com!stewart.hunt
- Distribution: world
- Message-ID: <60.435.4478.0N20DA5F@canrem.com>
- References: <4iscpl$bvr@vixen.cso.uiuc.edu>
- Date: Sat, 23 Mar 96 10:43:00 -0500
- Organization: CRS Online (Toronto, Ontario)
-
- At 4:18 AM on 23 Mar 96, Brent Busby said to All:
-
-
- BB> This was emailed out, but has gotten no replies so far. If anyone
- BB> can help, any information here would be appreciated. Thank you.
-
- BB> > Subject: I/O port addresses & interrupts
-
-
- BB> I'm in a bit of confusion about some things I'm doing here on the
- BB> A2386 that I've got, and since you've done some extensive hardware
- BB> hacking on Commodore bridgeboards, I thought I'd see what you think
- BB> about this...
-
- BB> I'm installing a ZyXEL 2-Ser/1-Par/1-Game I/O card and an ATI 4MB
- BB> Graphics Pro Turbo ISA UVGA card on the bridgeboard side of my
- BB> A3000T system. I've already got an Adaptec AHA-1542CF SCSI-II
- BB> controller installed successfully; the Janus Handler has to be
- BB> disabled to make room for the extended SCSI BIOS but still, it
- BB> works. My question is about all those memory addresses and
- BB> interrupts that the Commodore bridgeboard manual says shouldn't be
- BB> used. Many of them are pretty darned necessary to get a lot of
- BB> fairly basic things to work!
-
- BB> The first part of Appendix B of the manual goes something like:
-
- BB> B. Adding Peripherals
- BB> ---------------------
- BB> This appendix outlines the different types of expansion devices that
- BB> can be used by the Bridgeboard. Some of the I/O addresses used by
- BB> different expansion devices are already in use by the Bridgeboard.
- BB> To avoid conflicts, make sure your expansion
- BB> devices are not using the following addresses:
-
- Text from the C= manual deleted
-
- BB> So to sum up, the bridgeboard wants the "2Fx" ($2F8-2FF) COM2 serial
- BB> port's memory location, which leaves me screwed unless that's
- BB> actually just refering to people who load the Janus Handler and run
- BB> AMOUSE and they're just not saying that. (Is that what the deal is?
- BB> They're just saying that if you run AMOUSE and the Janus Handler,
- BB> that you'd better not have anything using
- BB> $2Fx because Janus is going to be writing all over that every time
- BB> you move your Amiga native side's mouse? Or am I really screwed and
- BB> it's just a port you can't *ever* use at all...??)
-
- Janus uses IRQ3 for hardware and software interrupts and thus is
- available for use. Basically the bottom line is that you cannot
- configure the second serial at the normal IRQ3 COM2 setting which is
- the default setting on most PC's. COM1 at IRQ4 is fine for the first
- serial port, while the second serial port can be either COM3 or COM4 at
- an used serial port that will not conflict with other hardware in your
- system. While 5 can be used, you typically will want this for the
- second parallel port LPT2:, so IRQ's such as 10, 11, or 12 would be
- more appropriate. I am using COM3 at IRQ 12 on my Lava complete multi
- I/O board. (416)-674-5942. This board contains floppy, IDE, 2x16550
- serial ports, bi-directional parallel, and game ports with very
- flexible IRQ settings. It works perfectly in the BB environment. While
- Windows allows you to configure the second serial port at a
- non-standard interrupt quite easily, under DOS a patch needs to be
- applied to the BIOS in order to have it properly recognized. Suitable
- software can be obtained from Computer Telecommunications Systems Inc.,
- 1-770-233-8632 or look for a file called CTSSPU34.ZIP on any well
- stocked IBM BBS software library. With the BIOS patch in place, MSD
- will recognize the second, non-standard IRQ serial port.
-
-
- BB> And...continuing, the bridgeboard wants "37x" ($378-37F) -- the
- BB> "normal" location of the LPT1 parallel port. Actually, I say
- BB> "normal" because when a PC boots, it does a search of $3BC (if
- BB> there's an monochrome video card installed; if not, skips this),
- BB> *then* the $378 address (the "normal" LPT1 location for PCs with
- BB> displays other than a Monochrome Graphics Adaptor), and *then* a
- BB> third address at $278 (which becomes the "normal" address of an LPT2
- BB> *second* parallel port, if there is one). So why not configure the
- BB> parallel port on the ZyXEL card as LPT2, give it a memory location
- BB> of $278, and just let the Janus LPT1/LPT1X printer utilities go
- BB> ahead and have their simulated LPT1 port at $378...? See anything
- BB> wrong with this idea?
-
- This is exactly where you want the second parallel port LPT2: at IRQ5.
- This is very useful because the emulated LPT1: is not a bidirectional
- parallel port, which is required for things like laplink connections.
-
- BB> And...the bridgeboard manual says the bridgeboard wants IRQ3.
- BB> That's normally COM2/COM4, but I may be out of hot water there if I
- BB> reassign that COM port pair to IRQ5, which is not mentioned as one
- BB> of the interrupts to stay away from. Any problem there?
-
- Do not use IRQ3. COM3 or COM4 could be configured at IRQ5, but again
- this is where LPT2: normally is. Sounds like your I/O card cannot be
- configured to use higher IRQ's which would make things a little more
- flexible. (IRQ's 10, 11, 12)
-
- BB> IRQ4 is traditionally COM1/COM3, but that interrupt is not
- BB> mentioned as a reserved one, so I should be able to go ahead and use
- BB> that as normal for the COM1/COM3 pair without problems.
-
- COM1 is normally IRQ4, but COM3 does not have to use IRQ4, in fact you
- want to set it to an unused IRQ like 5, 10, 11, or 12.
-
-
- BB> IRQ5 is not mentioned as reserved either, so this is the one that I
- BB> mentioned two paragraphs above as a proposed interrupt for the
- BB> COM2/COM4 pair since the manual lists the traditional IRQ3 as
- BB> reserved. Additionally, the ZyXEL card's parallel port would *also*
- BB> get this IRQ5, which should be okay since it's a printer and not an
- BB> interrupt driven device? Right...?
-
- Since I am using separate interrupts for LPT2: at IRQ5 and COM3 (and
- have used COM4) at IRQ 12, I can only say for sure that this does work.
-
- BB> IRQ7 is listed as reserved. If we let the bridgeboard go ahead and
- BB> have its LPT1 emulation, and make the ZyXEL parallel port an LPT2 on
- BB> IRQ5, we can leave IRQ7 alone, and this part will be okay, too,
- BB> right...?
-
- Yes
-
- BB> IRQ10 will be used by the ATI UVGA card. This IRQ is not listed as
- BB> reserved, so that's not the problem. What *might* cause a problem
- BB> is that it says in the card's manual -- and yes, I *know* this is
- BB> absolutely and completely retarded, but this is what it says -- that
- BB> the card reserves port addresses at $2E0-2EF. Heh. That's COM4,
- BB> folks. Imagine, a top rated UVGA video card that *steals* your COM4
- BB> I/O port like the shirt off your back. It may be okay though,
- BB> because if what I'm planning works as intended, I may not actually
- BB> run into any need for COM4. (I *still* think it's retarded.)
- BB> IRQ11 is currently assigned, without problems, to the Adaptec SCSI-
- BB> II board. So nothing can get IRQ11.
-
- Strange that your video card requires an interrupt? I am using an ATI
- Graphics Expression card and it does not use an interrupt. It does
- however use the COM4 address which forced me to change my second serial
- port configuration from COM4 IRQ12, to COM3 IRQ12 which works fine. I
- also thought this was a bizzare thing to do on ATI's part.
-
- I am also using a SoundBlaster 16 SCSI card which adds sound using
- IRQ10, and SCSI using IRQ11.(CD-ROM and ZIP Drive) The Janus Handler
- does not conflict with the SCSI, and in my case and all of the Janus
- functions work properly as they should.
-
-
- BB> And then there's that game port. It has no jumpers or DIP switches
-
- The game port on my I/O card required no configuration to be recognized
- and works fine.
-
-
- BB> Any comments appreciated.
-
- BB> --
- BB> Amiga /// | | "They had a glow-in-the-dark
- BB> 040 /// | Brent Busby ("Sequencer") | Santa in their
- BB> yard. Santa
- BB> \\\/// | claevius@prairienet.org | isn't radioactive,
- BB> is he?
- BB> \XX/ | | Cool beans. Nuclear Santa."
-
-
- Your I/O card is not quite a flexible as the LAVA, and the Video cards
- use of IRQ10 is unusual to say the least. I have worked with the BB
- under DOS, Windows, and OS/2. All ports when properly configured work
- just as they would on any PC under these OS's. Aread and Awrite also
- work under OS/2 as well, but a real mouse is required. I had AMouse
- working poorly in a DOS session, but I have a real mouse on COM1 which
- I normally use.
-
- The only real unsolved BB problem I have found is an incompatibility
- between the CPU microprocessor upgrades and the trancendental math
- functions when used in combination with a math coprocessor chip. While
- this does not cause any noticeable problems under DOS/Windows, it is a
- source of major problems under OS/2 and the math co-pro needs to be
- removed for proper operation. No one I know of has been able to come
- with a solution to this problem.
-
- I hope this has helped.
-
- Regards,
-
- Stewart Hunt
-
- .. "From this strange confusion grows a perverse communication" -- Siouxsie
- * Q-Blue 2.1 *
-