It's been a while since I used my vintage PCs, but for the 1542 I think I normally use IRQ 11, I/O port 240 and DMA 6. I *think* my BIOS address is C8000h.

I am going to be using this along with a Sound card and Video card and all the other normal cards including a VLB IDE controller.
I don't want any resource conflicts and I want to best setting that should not cause any problems with my other cards.

Keep in mind, that SCSI card's default settings conflict with the default settings of most soundblaster compatible cards, so make sure to check for conflicts there. The conflict is generally with IO port 330, but depending on the model of sound card it may conflict in other areas.

Okay. So what is the best settings for a Sound card and a VLB IDE controller.
What IRQ, DMA, and ports to use ?

If I use the suggested for the SCSI controller:
IRQ 11, I/O port 240 and DMA 6. I

Once you have all the basic stuff configured, like SoundBlaster and so on. Then use whatever avaliable resources that are left, for the SCSI controller. Does not matter that much if you use one IRQ or DMA over the other, as long as nothing is conflicting. In other words, there are no magical and golden settings. Just as long as it is not conflicting, then you will be all right.

Well there is a lists of suggested setting for I/O cards.

They're all functionally equivalent and won't have any effect on performance (unless you got a conflict mentioned earlier 🤣)

I think this is what I am looking for.
https://stason.org/TULARC/pc/pc_hardware_faq/ … hannels_go.html

It is simple... look up what the cards you are going to install use as I/O and DMA.
Then set the AHA-1542 to some configuration that does not conflict.
The settings @Anonymous Coward listed are a typical example, as you want to reserve I/O 330 and DMA 1 + 5 for sound card stuff.

One thing that is always difficult is that with PnP cards... these often use some obscure I/O ports.
So you should do this sequence:
Install system with VGA and AHA host adapter.
Then add and configure every additional card.
You will then see if any conflict occurs and know which card causes it.

For my part I use I/0 130, IRQ 11 and DMA 6 for the AHA-1542CF.

Another thing you need to be aware of is that with the AHA-1542CF you must set the shadow RAM to read/write!

The AHA-1452CF has its own shadow RAM in that regard that it copies its ROM to an onboard RAM, patched with the configuration you set, and then disables the ROM in favor of the RAM BIOS. So you may run into problems if you shadow its ROM read-only.

The default I/O of 330h sometimes collides with the midi port adress. I recommend the AHA-2842 VLB controller if you use a VLB board. Dont try to use an AMD Lance network controller. These are ISA busmasters, like the adaptec, but ISA does only support a single busmaster.

eisapc wrote:

The default I/O of 330h sometimes collides with the midi port adress. I recommend the AHA-2842 VLB controller if you use a VLB board. Dont try to use an AMD Lance network controller. These are ISA busmasters, like the adaptec, but ISA does only support a single busmaster.

No, I am going to use the 3com 3c509 ISA ethernet III network card.

This is a good reference for I/O card settings.
Can anyone elaborate on this reference and make it better or fill in the blanks ?

Description […]
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Description

This item is from the PC Hardware FAQ, by Willie Lim and Ralph Valentino with numerous contributions by others. (v1.25).

2.49 Where do all the IRQ's and DMA Channels go?

[From: wlim@lehman.com (Willie Lim)]

[From: r.j.mersel@is.twi.tudelft.nl (Rob Mersel)]

(Note that DRQ is the DMA Channel)

Default IRQ/DRQ settings AT systems:

IRQ : IO BASE : DRQ : Card or Device
ADDRESS
(HEX)
=== ======= === ================
* * 0 unassigned (? bit DMA)
* * 1 unassigned (8 bit DMA)
* * 3 unassigned (8 bit DMA)
* * 5 unassigned (16 bit DMA)
* * 6 unassigned (16 bit DMA)
* * 7 unassigned (16 bit DMA)
0 * * timer (reserved)
1 * * keyboard (reserved)
2 * * interrupt 8-15 (cascade) (see Q 2.40)
3 2E8-2EF * COM4:
3 2F8-2FF * COM2:
4 3E8-3EF * COM3:
4 3F8-3FF * COM1:
5 278-27F * LPT2:
6 3F0-3F7 2 Floppy drive controller
7 378-37F * LPT1: (PRN:)
8 * * real-time clock (reserved)
9 * * unassigned (see Q 2.40)
10 * * unassigned
11 * * unassigned
12 * * unassigned
13 * * math co-processor
14 1F0-1F7 * Hard drive controller (drive 0)
14 3F6-3F7 * Hard drive controller (drive 1)
15 170-177 * Secondary hard drive controller (drive 2)
15 376-377 * Secondary hard drive controller (drive 3)
Adapter card IRQ/DRQ settings:

IRQ : IO BASE : DRQ : Card or Device
ADDRESS
(HEX)
=== ======= === ================
* 200-207 * Game port
2 330 * MPU-401 Emulation (PAS 16)
3 300 * 3Com Etherlink II, II/TP, II/16, II/16TP, 16/16TP
3 300 * Novell NE2000
3 300 * SMC/Western Digital 8003EP, 8013EWC, 8013WB
5 368 * Ungermann-Bass Ethernet NIUpc (long), NIUpc/EOTP (short)
5 ??? * DEC etherWORKS LC, Turbo, Turbo/TP
5 220 1 Sound Blaster Emulation (PAS 16)
5 220-22F 1 Sound Blaster 2.0 (default)
* 338-339 * Sound Blaster 2.0 FM music chip
5 A20 5 Proteon P1390
7 * 3 Pro Audio Spectrum 16 (PAS 16)
9 300 5 Boca Ethernet BEN100, BEN102, BEN300

Default IRQ/DRQ settings XT systems:

IRQ IO BASE DRQ Card or Device
ADDRESS
(HEX)
=== ======= === ===============
* * 0 DRAM-refresh (used on motherboard only?)
* * 1 unassigned
0 * * timer (reserved)
1 * * keyboard (reserved)
2 * * unassigned
3 2E8-2EF * COM4:
3 2F8-2FF * COM2:
4 3E8-3EF * COM3:
4 3F8-3FF * COM1:
5 ? 3 Hard drive controller
6 3F0-3F7 2 Floppy drive controller
7 378-37F * LPT1: (PRN:)

I love that particular series of cards because you can disable the BIOS completely. If you're not booting from SCSI, you don't need it, and it just slows down the POST process while it scans for drives. With the BIOS disabled, you can have SCSI without having to wait like you have SCSI. 😀

I have two 1542s (ISA), a 2840 (VLB), and a 2940 (PCI). I think I usually set my IO port to 140, and IRQ to 11. Maybe it was 10. Not sure. It was the one not used by the network card. (3Com 509 on the ISA systems, 905 on the PCI systems.)

To reiterate the advice here, stop worrying about the "recommended" settings. The only thing that matters is that it doesn't conflict with anything else. Take your lists above of the common AT port, IRQ, and DMA reservations, add anything used by your sound, network, and video cards. Pick anything that's left to assign to your SCSI card. That's the one and only correct way to do it, unless you're copying from someone else that has the EXACT same pile of hardware you have.

Well I plan on using the Media Vision spectrum pro PAS16 sound card too. And I know it is known to conflict with other cards by default so making a list first of all the cards and settings is a good starting point before I begin the installations.

PAS16, SCSI, and net? Well, good luck. 😀

Luckily, my PAS16 has a SCSI interface built-in. Makes it a little easier (but it's still the equivalent of two sound cards.)

SirNickity wrote:

PAS16, SCSI, and net? Well, good luck. 😀

Luckily, my PAS16 has a SCSI interface built-in. Makes it a little easier (but it's still the equivalent of two sound cards.)

Good point, I have some Media Vision sound cards without scsi too.
Any way to disable SCSI on this Media Vision PAS16 card ?

The PAS16 doesn't have a SCSI BIOS on it, so as long as you don't load the SCSI driver for it, it is "disabled".

Anonymous Coward wrote:

The PAS16 doesn't have a SCSI BIOS on it, so as long as you don't load the SCSI driver for it, it is "disabled".

Great, I am going to make a spreadsheet and add all my cards with settings.
Hope for the best that they work and as intended.