IBM AT ISA bus card overclock

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Josh

I have a machine that interfaces to a IBM AT 286 Xenix computer by
means of an ISA card. I would like to upgrade this machine to
something more recent like a 486 or pentium class processor inorder to
decrease compiling times when prorgams are written.

The problem I am encoutering is that the card is not recognized on the
new systems ISA bus. I'm running linux on the new system and lspci and
pnpdump show nothing. Is there anyways for me to overclock this cards
speed to match the new bus speed, or could I underclock the bus speed
of the new system so it will recognize the card?
 
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I have a machine that interfaces to a IBM AT 286 Xenix computer by
means of an ISA card. I would like to upgrade this machine to
something more recent like a 486 or pentium class processor inorder to
decrease compiling times when prorgams are written.

The problem I am encoutering is that the card is not recognized on the
new systems ISA bus. I'm running linux on the new system and lspci and
pnpdump show nothing. Is there anyways for me to overclock this cards
speed to match the new bus speed, or could I underclock the bus speed
of the new system so it will recognize the card?
Click to expand...

A card that's old enough to have shipped in a 286 isn't going to support ISA
Plug & Play, which was only introduced alongside Windows 95. Whatever
resources (I/O, IRQ, etc.) the card is configured to use (whether through
jumpers or a fixed configuration set by the hardware designer) it'll just go
ahead and take for itself. lspci won't show anything different because the
card you're trying to use is not a PCI card. I've never used pnpdump (ISA
PnP was an evil hack by Microsoft that tended to work only when it felt like
working), but it shouldn't list anything different either because while your
card is an ISA card, it doesn't support ISA PnP.

IIRC, ISA was never specced for speeds beyond 8 MHz. Some early 10-MHz
machines might've overclocked the bus a bit, but I don't think there was
ever a board produced for anything from the 386 on up that ran the ISA bus
faster than 8 MHz. For a card pulled from a 286, ISA bus speed in a newer
machine shouldn't be a problem. The only time I've had to underclock a
machine to get a card working was when I needed to hook up the MFM
controller and ST225 from a PC/XT to a newer machine to get DOS loaded onto
the drive (my copy of DR DOS 6 is on 5.25" high-density floppies). I think
the ISA bus speed remained constant; it was just the processor that was
slowed from 233 MHz to somewhere around 90-100 MHz. I think I had to
disable the L1 and L2 caches, too. That might've been an issue with the
card's firmware not wanting to run right at faster speeds more than a
bus-speed issue.

_/_
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ISA card
lspci and pnpdump show nothing
Click to expand...

lspci is not lsisa :)
and the card might be configured by jumpers, not a p&pray

what exactly is that card ? what OS was that 286 running ? have you got
any drivers for it ? How are you going to drive it ? there is no way to
simply "look" whats connected to ISA bus afaik beside BIOS
initialisation.


Pozdrawiam.
 
Josh said:
I have a machine that interfaces to a IBM AT 286 Xenix
computer by means of an ISA card. I would like to upgrade
this machine to something more recent like a 486 or pentium
class processor inorder to decrease compiling times when
prorgams are written.
Click to expand...
The problem I am encoutering is that the card is not
recognized on the new systems ISA bus. I'm running linux on
the new system and lspci and pnpdump show nothing. Is there
anyways for me to overclock this cards speed to match the
new bus speed, or could I underclock the bus speed of the
new system so it will recognize the card?
Click to expand...

Well, I'll presume you have driver source and skills to migrate
it to Linux. Otherwise, you'll have to migrate that Xenix.

A couple of things you should check -- first, are the IRQs
that card needs available on the ISA bus, or have they been
stolen by PCI?

Second, is that ISA bus running at satisfactory speed?
Around the time of the 486/Pentium, PCI became primary
and the ISA bus was hung off it through the Southbridge.
This dramatically hurt performance, IIRC from ~5 MByte/s on
a good ISA bus down to ~1 MByte/s typical through Southbridge.

-- Robert
 
IIRC, ISA was never specced for speeds beyond 8 MHz. Some early
10-MHz machines might've overclocked the bus a bit, but I don't
think there was ever a board produced for anything from the 386 on
up that ran the ISA bus faster than 8 MHz
Click to expand...

well I'v got ADAPTEC SCSI ISA card that can work with ISA up to 12MHz


Pozdrawiam.
 
The card is a not a well know card. It is an interface to a machine
used for automatic testing of digital ICs. It has no jumpers or any
settings at all onboard. It is running on SCO Xenix 2.2 System V. My
skill on Xenix or quite lacking. I've been fumbling around with
ancient versions of commands I know from linux trying to feel my way
around the system. A manual or man pages would be a god send.

I have a linux distro with linux-abi installed in the kernel waiting
for me to transfer the digital testing software to it. I wanted to
make sure the card would work before I undertook either:
a) the uucp transfer of the software or
b) the (5.25)floppy shuffle
But I guess that isn't going to happen since it sounds like the card
is software dependant. Mounting the drive in the new system is out of
the question since the linux kernel module that claims to support
sysv, xenix, and coherent file systems did not work for mounting the
drive to the new system(unless I have a wrong syntax, but i double
checked it with other people).
Linux-abi claims support for xenix286 binaries and that is how I plan
to run the old software on the new system. Unfortunately, I dont have
the driver source. Do you think that this will be a major obstacle?
The company that made the machine is no longer in buisness. I think
the driver is built into the testing software.

pnpdump seems to go through every address on the bus line to search
for cards. nothing shows up from it, but possibly it is searching for
pnp devices or some type of pnp response(I'm not that familiar with
the inner workings of pnp).

Is there anyway for me to find the IRQ of this card on the xenix
system so I can make sure it is open on the new system? I will have to
research this.

There are also problems reading 5.25" floppies on the newer linux
system.
 
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A card that's old enough to have shipped in a 286 isn't going to support ISA
Plug & Play, which was only introduced alongside Windows 95. Whatever
resources (I/O, IRQ, etc.) the card is configured to use (whether through
jumpers or a fixed configuration set by the hardware designer) it'll just go
ahead and take for itself. lspci won't show anything different because the
card you're trying to use is not a PCI card. I've never used pnpdump (ISA
PnP was an evil hack by Microsoft that tended to work only when it felt like
working), but it shouldn't list anything different either because while your
card is an ISA card, it doesn't support ISA PnP.
Click to expand...

IIRC the M$ specs for ISA PnP simply stated that the PnP ISA card had to
have one alternative for each of IRQ, I/O address and DMA, IOW two of each
resource it required and that it be capable of switching between them. Yes
it was a hack and it caused as much trouble as benefit... and many BIOSs
did not handle things right anyway.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??
 
I have a machine that interfaces to a IBM AT 286 Xenix computer by
means of an ISA card. I would like to upgrade this machine to
something more recent like a 486 or pentium class processor inorder to
decrease compiling times when prorgams are written.
Click to expand...

Just to be clear: it's the IBM AT 286 that you want to replace - yes?
The problem I am encoutering is that the card is not recognized on the
new systems ISA bus. I'm running linux on the new system and lspci and
pnpdump show nothing. Is there anyways for me to overclock this cards
speed to match the new bus speed, or could I underclock the bus speed
of the new system so it will recognize the card?
Click to expand...

Do you know which resources the ISA card uses - IOW does it have mapped
memory... on top of the usual IRQ & I/O address?... and does it use DMA?
Also what is this "new system"? Can you not tell what this ISA card is or
what it does? I wish you'd been more specific. Depending on the resources
required and the target computer, there are several things which could go
wrong.

There were systems produced, in the 386/486 timeframe which used chipsets
which did not work with many cards which had mapped memory on them - the
memory bus was slightly different from IBM's original AT standard and
addresses were latched with edge triggered D flip-flops... if I'm
remembering things right.

Overclocking the ISA card is out but there were many mbrds produced in the
early PCI days which had speed programmable ISA buses: typically, in the
BIOS Setup you could set the speed ratio of PCI:ISA to 4:1(standard 8MHz),
3:1, 5:2 etc. The other thing to watch is that with PnP BIOSs, there was
often the option to "reserve" IRQs and I/O addresses in BIOS Setup, which
told the BIOS to block their use for PnP and allow them to be dedicated to
a specific card on the ISA bus.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??
 
I have a machine that interfaces to a IBM AT 286 Xenix computer by
means of an ISA card. I would like to upgrade this machine to
something more recent like a 486 or pentium class processor inorder to
decrease compiling times when prorgams are written.

The problem I am encoutering is that the card is not recognized on the
new systems ISA bus. I'm running linux on the new system and lspci and
pnpdump show nothing. Is there anyways for me to overclock this cards
speed to match the new bus speed, or could I underclock the bus speed
of the new system so it will recognize the card?
Click to expand...

A photo of the card may be of help. Some older jumperless non-PnP ISA
cards used a configuration utility to set up the card's resources. My
old 486 machine has a sound card of this type. I also have a non-PnP
jumperless NE2000 compatible NIC. In the case of the NIC, the config
utility was used to intially set up the card's resources, after which
they would be written to a serial EEPROM chip. In the case of the
sound card, the resources were not stored on the card but were
initialised at bootup by means of a statement in the autoexec.bat
file.

BTW, I also have a specialised ISA interface card for a device
programmer and IC tester (Sunshine Expro 60). I keep my old 486 box
alive because this card does not work reliably in faster systems, even
after experimenting with its wait state jumpers.


- Franc Zabkar
 
The card is a not a well know card. It is an interface to a machine
used for automatic testing of digital ICs. It has no jumpers or any
settings at all onboard.
Click to expand...

It may have some hardwired etches. For example, there may be an etch
that configures the card as primary or secondary to allow for two
cards in the one box.
It is running on SCO Xenix 2.2 System V. My
skill on Xenix or quite lacking. I've been fumbling around with
ancient versions of commands I know from linux trying to feel my way
around the system. A manual or man pages would be a god send.

I have a linux distro with linux-abi installed in the kernel waiting
for me to transfer the digital testing software to it. I wanted to
make sure the card would work before I undertook either:
a) the uucp transfer of the software or
b) the (5.25)floppy shuffle
But I guess that isn't going to happen since it sounds like the card
is software dependant. Mounting the drive in the new system is out of
the question since the linux kernel module that claims to support
sysv, xenix, and coherent file systems did not work for mounting the
drive to the new system(unless I have a wrong syntax, but i double
checked it with other people).
Click to expand...

Is the drive an IDE type? Older 286 machines used a special MFM/RLL
interface card, for example. Installing this card into a machine with
its own IDE ports would not work. Sorry if this was stating the
obvious.
Linux-abi claims support for xenix286 binaries and that is how I plan
to run the old software on the new system. Unfortunately, I dont have
the driver source. Do you think that this will be a major obstacle?
The company that made the machine is no longer in buisness. I think
the driver is built into the testing software.
Click to expand...

That's the case with my Expro 60 device programmer/tester interface
card. The card's resources are invisible to Windows.
pnpdump seems to go through every address on the bus line to search
for cards. nothing shows up from it, but possibly it is searching for
pnp devices or some type of pnp response(I'm not that familiar with
the inner workings of pnp).

Is there anyway for me to find the IRQ of this card on the xenix
system so I can make sure it is open on the new system? I will have to
research this.
Click to expand...

If at all possible, please post a photograph or scan of both sides of
your card on your web space. The part numbers of the various chips may
give a clue. Some people who watch comp.sys.ibm.pc.HARDWARE.CHIPS are
actually hardware people. ;-)

For example, knowing whether the card occupies one or two connectors
would define it as an 8 bit or 16 bit card. An 8 bit card would be
limited to IRQs 3,4,5,7 and 9. If the card contains no intelligent
chips or chipsets (eg microcontrollers + RAM + ROM), then that would
suggest that all the resources would come under software control. If
the card has a PAL IC, then that is where I would be looking to
determine its IO address. My Expro 60's interface card is polled
rather than interrupt driven. You can determine whether this is the
case for your card by inspecting the IRQ pins on the ISA fingers.
Unused IRQs would have no copper traces leading to their respective
ISA pins. IRQs 3,4,5,7,9 connect to pins B25, B24, B23, B21, and B4.
IRQs 10,11,12,15 connect to D3, D4, D5, and D6. You can do the same
for the DMA pins.
There are also problems reading 5.25" floppies on the newer linux
system.
Click to expand...

What kind of problem? Can you format a fresh diskette on this drive?
Have you tried using DOS to test your floppy drive?


- Franc Zabkar
 
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