AST 4 PORT card information

Mapping the SW's to the functions:

SW1-1 : IRQ2   SW2-1 : IRQ5   SW3-1 : XA1
SW1-2 : IRQ3   SW2-2 : IRQ6   SW3-2 : XA0
SW1-3 : IRQ4   SW2-3 : IRQ7   SW3-3 : INT
                              SW3-4 : SHR

XA0 (SW3-2)	Address range	OFF : 1A0h (1B0h) - 1BFh ON : 2A0h (1B0h) - 1BFh
XA1 (SW3-1)	Operation mode port J1 & J2	OFF : 4port mode ON : COM1 & COM2
INT (SW3-3)	Interrupt enable	OFF : interrupt disable ON : interrupt enable
SHR (SW3-4)	Share interrupt with other 4port	OFF : Single 4 port card ON : Two 4 port cards

The INT switches are trival. Just put one IRQ, a free one, ON.

Summarised:

SHR is only on if you want two 4Ports to share the same interrupt. Make sure they use different address ranges (XA0).
INT is only off if you want to use the card with your own, polling based, routines.
XA0 selects the IO-addresses.
XA1 selects the mode of the J1 & J2 port: as COM1 & COM2 or as special ports, just as J3 & J4.
For Linux, XA0 OFF the board is defined as ttyS4 - ttyS7. XA0 ON uses ttyS8 - ttyS11. Specify IRQ9 in rc.serial if you use IRQ2
If you want a login on one of the ports, add something like the following to /etc/inittab:
s4:45:respawn:/sbin/agetty 9600 ttyS4 vt100
Check your own inittab for other examples!
My cable has the connectors numbered J1 to J4 for the individual ports and J5 for the card connector. J1 corresponds to the lowest UART on the card, and the lowest in the memory range (1A0h, 2A0h or COM1).

Some DOS software I found somewhere on an AST ftp server a long time ago (I forgot where).
ASTCOM2.ZIP A driver
CC832TST.ZIP A test program
FOURPORT.ZIP Source code examples.
Cable wiring.

Don't forget to dedicate the IRQ to ISA in the BIOS configuration setup. Sharing it with a PCI card does not result in an error message (with Linux), but it works really slow (1 character in ten seconds or so).

A long time ago I asked for the info presented above in comp.os.linux.hardware, and got the following replies:
(I scanned it much later, so beware for OCR errors)

Date: Wed, 17 Jul 96 19:53 EDT
From: dave@sillub.ocunix.on.ca (Dave Bullis)
To: fjkr@gatekeep (Fred Jan Kraan)
Subject: Re: AST Fourport dipsetting info needed
Cc: dave@sillub.ocunix.on.ca
Newsgroups: comp.os.linux.hardware
Organization: Sillub Technology
Reply-To: sillub@ftn.net
X-Newsreader: TIN [version 1.2 PL2]
Status: RO
X-Status: D

In article  you wrote:
: This is what I found out:

: XAO XA1  addr
: OFF OFF  1AOh-1BFh
: ON  OFF  2AOh-2BFh
: OFF ON   1BOh-1BFh
: ON  ON   ??

: Setting the card to address 1AOh-lBFh, interrupt 2 and SHR ON,
: and enable the card with /etc/rc/d/rc.serial
: seems to work but sends characters to the port at a rate of
: approximately one character in ten seconds (19200 baud), so
: something must be wrong.

: Thanks a greetings,

Fred Jan Kraan

Do you have SW3-3 (INT) ON?
And do are setting irq 9 with setserial?

/etc/setserial -v /dev/ttyS4 uart 16450 port OxlAO irq 9
/etc/setserial -v /dev/ttyS5 uart 16450 port OxlA8 irq 9
/etc/setserial -v /dev/ttyS6 uart 16450 port OxlBO irq 9
/etc/setserial -v /dev/ttyS7 uart 16450 port OxlB8 irq 9

Worked for me before I switched motherhoards had lost a slot for it.

Dave Bullis	sillub0ftn.net

Dave Bullis                sillub@ftn.net
Sillub Technology

Date: Wed, 17 Jul 1996 15:11:42 +1000
From: leon garde 
Message-Zd: <199607170511.PAA06906@praetor.hna.com.au>
To: fjkr@gatekeep
Subject: Re: AST Fourport dipsetting info needed
Newsgroups: comp.os.linux.hardware
References: 
Content-Type: text
Status: RO
X-Status:

In comp.os.linux.hardware you write:

>Some time ago I bought a AST Fourpart card in a DEC repacking.
>Alas the manual was replaced by quite useless DEC installation
>manuals.

>Now I cannot find the right dip-switch settings to configure
>the card for Linux. Can someone send me an installation
>abstract or a pointer to the manual?

>This is the information for the card:

>AST CC-832
>FCC ID: DJK68YCC832

>Dip switches:

> INT
>  2    3    4    5    6    7   XA1 XAO INT SHR
>+-------------++-------------++---------------+
>|             ||             ||               |
>|             ||             ||               |
>|             ||             ||               |
>+-------------++-------------++---------------+

>This is what I found out:

>XAO XA1  addr
>OFF OFF  1AOh-1BFh
>ON  OFF  2AOh-2BFh
>OFF ON   1BOh-1BFh
>ON  ON   ???
ON  ON   2BOh-2BFh . well, i have a recollection of it being so simple :)
>Setting the card to address 1AOh-lBFh, interrupt 2 and SHR ON,
>and enable the card with /etc/rc/d/rc.serial
>seems to work but sends characters to the port at a rate of
>approximately one character in ten seconds (19200 baud), so
>something must be wrong.

turn SHR off. it is for compatibility mode
INT is on, it is enable interrupt.

but if that doesnt work, change the settings again.
there are only 4 different settings to try :)

leon

Date: Tue, 16 Jul 1996 20:56:31 +0100 (BST)
From: Bill Hay 
To: fjkr@gatekeep
Subject: Re: AST Fourport (fwd)
Message-Id: 
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Status: RO
X-Status:

"You know what really burns my ass?" – Tinya Wazzo Bill Hay

---------- Forwarded message ----------
Date: Mon, 3 Jul 1995 23:40:03 -0500
From: Stephen Denny 
To: wish@dumain.demon.co.uk
Newgroups: comp.os.linux.hardware
Subject: Re: AST Fourport

In article  you write:
>I've just acquired 2 AST Fourports.  Each has 4 chips marked 16C450.  These
>look to be fairly easy to remove but can they be upgraded to 16550s?
>There are three switch blocks on each card   The first two are obviously for
>selecting the IRQ used.  The third has four switches marked XA1, XAO, INT
>and SHR.  Any idea what these do ?

I am using Fourports here with linux with excellent results.  Yes,
immediately replace the 15450s to 16550A versions.  If you need a cheap
source I can pass mine along.  I buy them 20 at a time.

Since I buy my Fourports new, I have complete (HA) documentation sets.
I'll try to summarize the switches below, but if you have further questions
let me know.

A summary first (this is how I set mine).

IRQ2  up (obviously I use this)
IRQ3  dn
IRQ4  dn

IRQ5  dn
IRQ6  dn
IRQ7  dn

compatible mode	         dn
high addr range	         dn [2AO]
IRQ sharing off	         up
reserved - set off only  dn

from the manual:

IRQx: Enable only one interrupt request (IRQ) line.
If there are two Async Cluster Adapters [fourports]
in your system, configure both for the same IRQ.

compatible mode: You might configure your first Async Cluster
Adapter [fourport) board for compatible mode if your PC-AT has a
second operating system that requires COM1 and COM2.
Also known as Enhanced mode, the second (fourport) must be
in enhanced mode.
[Basically if you want to use two other serial ports prior to
the fourport use this to make the fourport skip them.]
high addr range [I/0 Address): First board: high address range
(SW3-2 ON).  Second board: low address range (SN3-2 OFF).
In enhanced mode, the high address range is 02A0-02BFh, and the
low address range is 01A0-01BFh.

interrupt sharing: Enabled: (SW3-3 OFF).  This setting allows two
fourports in the same

Latest update: 2004-05-22