No IRQ for graphic card in Windows 95

[Guest Franc Zabkar]

I have two 486/586 machines running Win95B. One has a Cirrus Logic VLB

graphics card based on a CL-GD5428 chipset, the other has an S3 Trio

V64+ PCI card. The latter card has a 2-pin interrupt header which I

have jumpered, and I have also enabled "assign IRQ to VGA" in the BIOS

setup.

 

Neither machine assigns an IRQ to its graphics card. It appears that

these cards are polled, much like standard (non-EPP/ECP) parallel

printer ports which also don't get an IRQ in Device Manager.

 

OTOH, my Win 98SE box does assign an IRQ to its PCI card (Diamond

Stealth III S540). Is this normal behaviour? FWIW, both motherboards

have UMC chipsets.

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Jeff Richards]

Re: No IRQ for graphic card in Windows 95

 

What software are you still using that requires an IRQ for VGA? You should

be able to update it to a later product.

--

Jeff Richards

MS MVP (Windows - Shell/User)

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:qajh94hkd8r645v2j5juroq41q8f7c71v0@4ax.com...

>I have two 486/586 machines running Win95B. One has a Cirrus Logic VLB

> graphics card based on a CL-GD5428 chipset, the other has an S3 Trio

> V64+ PCI card. The latter card has a 2-pin interrupt header which I

> have jumpered, and I have also enabled "assign IRQ to VGA" in the BIOS

> setup.

>

> Neither machine assigns an IRQ to its graphics card. It appears that

> these cards are polled, much like standard (non-EPP/ECP) parallel

> printer ports which also don't get an IRQ in Device Manager.

>

> OTOH, my Win 98SE box does assign an IRQ to its PCI card (Diamond

> Stealth III S540). Is this normal behaviour? FWIW, both motherboards

> have UMC chipsets.

>

> - Franc Zabkar

> --

> Please remove one 'i' from my address when replying by email.

[Guest MEB]

Re: No IRQ for graphic card in Windows 95

 

Been awhile but,,, is it an updated 95B? IF so check to ensure the driver

has 95 support. You may find the older drivers work better than the newer.

 

PnP (and IRQ assignment) wasn't that great in 95 [or that era] so you may

want to manually assign IRQs by SLOT or EDGE in the BIOS, then check the

Device for any setting adjustments.

Older 486 machines had limited BIOS support... early 586 (Socket 5/7) BIOSs

were also somewhat limited.

The VLB card MAY be difficult to get set properly.

 

What motherboards are we talking about?

 

--

MEB

http://peoplescounsel.orgfree.com

--

_________

 

 

 

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:qajh94hkd8r645v2j5juroq41q8f7c71v0@4ax.com...

| I have two 486/586 machines running Win95B. One has a Cirrus Logic VLB

| graphics card based on a CL-GD5428 chipset, the other has an S3 Trio

| V64+ PCI card. The latter card has a 2-pin interrupt header which I

| have jumpered, and I have also enabled "assign IRQ to VGA" in the BIOS

| setup.

|

| Neither machine assigns an IRQ to its graphics card. It appears that

| these cards are polled, much like standard (non-EPP/ECP) parallel

| printer ports which also don't get an IRQ in Device Manager.

|

| OTOH, my Win 98SE box does assign an IRQ to its PCI card (Diamond

| Stealth III S540). Is this normal behaviour? FWIW, both motherboards

| have UMC chipsets.

|

| - Franc Zabkar

| --

| Please remove one 'i' from my address when replying by email.

[Guest Lil' Dave]

Re: No IRQ for graphic card in Windows 95

 

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:qajh94hkd8r645v2j5juroq41q8f7c71v0@4ax.com...

>I have two 486/586 machines running Win95B. One has a Cirrus Logic VLB

> graphics card based on a CL-GD5428 chipset, the other has an S3 Trio

> V64+ PCI card. The latter card has a 2-pin interrupt header which I

> have jumpered, and I have also enabled "assign IRQ to VGA" in the BIOS

> setup.

>

> Neither machine assigns an IRQ to its graphics card. It appears that

> these cards are polled, much like standard (non-EPP/ECP) parallel

> printer ports which also don't get an IRQ in Device Manager.

>

> OTOH, my Win 98SE box does assign an IRQ to its PCI card (Diamond

> Stealth III S540). Is this normal behaviour? FWIW, both motherboards

> have UMC chipsets.

>

> - Franc Zabkar

> --

> Please remove one 'i' from my address when replying by email.

 

In reference to the parallel port, you may mean that the standard port is

not assigned any DMA designation. In any case, should not be assigned a

hardware irq.

--

Dave

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Wed, 6 Aug 2008 00:20:28 -0400, "MEB" <meb@not here@hotmail.com>

put finger to keyboard and composed:

>Been awhile but,,, is it an updated 95B? IF so check to ensure the driver

>has 95 support. You may find the older drivers work better than the newer.

>

>PnP (and IRQ assignment) wasn't that great in 95 [or that era] so you may

>want to manually assign IRQs by SLOT or EDGE in the BIOS, then check the

>Device for any setting adjustments.

 

The only available option is to choose edge triggered or level

triggered interrupts, but it makes no difference either way.

>Older 486 machines had limited BIOS support... early 586 (Socket 5/7) BIOSs

>were also somewhat limited.

> The VLB card MAY be difficult to get set properly.

 

The datasheet for the CL-GD542x chip shows the chip's IRQ pin as being

tristate-able which means it can be turned off. This pin goes active

when the "CL-GD542x has reached the end of an active field.

Specifically, the transition occurs at the beginning of the bottom

border."

 

So it appears that the graphics card only uses the IRQ pin to signal

when it is about to scan the last line of each frame. Maybe the driver

doesn't need to know this and therefore doesn't bother assigning an

IRQ ???

> What motherboards are we talking about?

>

>--

> MEB

> http://peoplescounsel.orgfree.com

 

The AMD 5x86 board is a "4IP-UMC-AIO" and uses a UMC UM8881F/UM8886BF

northbridge/southbridge plus a UM8663BF/UM8667 Super I/O chipset.

 

The 486 board is a Biostar MB1433/40/50UIV with a UMC498 chipset

(according to the BIOS ID).

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Wed, 6 Aug 2008 07:36:25 -0500, "Lil' Dave"

<spamyourself@virus.net> put finger to keyboard and composed:

>"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

>news:qajh94hkd8r645v2j5juroq41q8f7c71v0@4ax.com...

>>I have two 486/586 machines running Win95B. One has a Cirrus Logic VLB

>> graphics card based on a CL-GD5428 chipset, the other has an S3 Trio

>> V64+ PCI card. The latter card has a 2-pin interrupt header which I

>> have jumpered, and I have also enabled "assign IRQ to VGA" in the BIOS

>> setup.

>>

>> Neither machine assigns an IRQ to its graphics card. It appears that

>> these cards are polled, much like standard (non-EPP/ECP) parallel

>> printer ports which also don't get an IRQ in Device Manager.

>>

>> OTOH, my Win 98SE box does assign an IRQ to its PCI card (Diamond

>> Stealth III S540). Is this normal behaviour? FWIW, both motherboards

>> have UMC chipsets.

>>

>> - Franc Zabkar

>

>In reference to the parallel port, you may mean that the standard port is

>not assigned any DMA designation. In any case, should not be assigned a

>hardware irq.

 

My understanding is that a standard 8-bit unidirectional, 8-bit

bidirectional, or 4-bit nibble mode bidirectional parallel port does

not get an IRQ or a DMA resource. In fact I have removed the IRQ

jumper for my SPP port and it still works. OTOH, an EPP port gets an

IRQ but no DMA, while an ECP port gets both an IRQ but no DMA.

 

See http://www.beyondlogic.org/spp/parallel.htm

 

"The Parallel Port's interrupt request is not used for printing under

DOS or Windows. Early versions of OS-2 used them, but don't anymore."

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Wed, 6 Aug 2008 09:35:32 +1000, "Jeff Richards"

<JRichards@msn.com.au> put finger to keyboard and composed:

>What software are you still using that requires an IRQ for VGA? You should

>be able to update it to a later product.

 

I always thought that interrupts were handled by the driver, not the

application. In any case, neither machine appears to require an IRQ

for its graphics card, but I was just curious as to why not.

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Thu, 07 Aug 2008 07:27:04 +1000, Franc Zabkar

<fzabkar@iinternode.on.net> put finger to keyboard and composed:

 

Sorry that should read ...

 

"an EPP port gets an IRQ but no DMA, while an ECP port gets both an

IRQ and a DMA."

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Jeff Richards]

Re: No IRQ for graphic card in Windows 95

 

The interrupt handler is installed by the driver, but it's optional and it

is only a very small number of applications that expect the interrupt to

occur, and in almost all cases they will check on startup that the handler

is installed and interrupts are occurring and will usually fail to run if

they aren't. It's to do with synchronising screen updates to the refresh

period. I can't think of any software I've used in a long time that needs

the interrupts, but then I don't play a lot of games.

--

Jeff Richards

MS MVP (Windows - Shell/User)

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:pprh94daipfdgfbn72q6ilbdrs9gepjcj6@4ax.com...

> On Wed, 6 Aug 2008 09:35:32 +1000, "Jeff Richards"

> <JRichards@msn.com.au> put finger to keyboard and composed:

>

>>What software are you still using that requires an IRQ for VGA? You

>>should

>>be able to update it to a later product.

>

> I always thought that interrupts were handled by the driver, not the

> application. In any case, neither machine appears to require an IRQ

> for its graphics card, but I was just curious as to why not.

>

> - Franc Zabkar

> --

> Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Wed, 6 Aug 2008 00:20:28 -0400, "MEB" <meb@not here@hotmail.com>

put finger to keyboard and composed:

>Been awhile but,,, is it an updated 95B? IF so check to ensure the driver

>has 95 support. You may find the older drivers work better than the newer.

>

>PnP (and IRQ assignment) wasn't that great in 95 [or that era] so you may

>want to manually assign IRQs by SLOT or EDGE in the BIOS, then check the

>Device for any setting adjustments.

>Older 486 machines had limited BIOS support... early 586 (Socket 5/7) BIOSs

>were also somewhat limited.

> The VLB card MAY be difficult to get set properly.

>

> What motherboards are we talking about?

>

>--

> MEB

> http://peoplescounsel.orgfree.com

 

I just checked my old Win95B backups for my current socket 7

motherboard (M571, PCChips). There is no IRQ assigned to the onboard

VGA (SiS 5597/5598). However, the same hardware under Win98SE *does*

get an IRQ. Unfortunately I can't be certain whether "assign IRQ to

onboard VGA" was enabled in the BIOS in both instances.

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Thu, 07 Aug 2008 15:32:48 +1000, Franc Zabkar

<fzabkar@iinternode.on.net> put finger to keyboard and composed:

>I just checked my old Win95B backups for my current socket 7

>motherboard (M571, PCChips). There is no IRQ assigned to the onboard

>VGA (SiS 5597/5598). However, the same hardware under Win98SE *does*

>get an IRQ. Unfortunately I can't be certain whether "assign IRQ to

>onboard VGA" was enabled in the BIOS in both instances.

 

Just checked my BIOS again. The option is actually to "assign IRQ to

PCI VGA". There is no such option for the onboard VGA, so it does look

like Win95 doesn't assign an IRQ to the graphics card.

 

The drivers are here:

http://driver.sis.com/graphic/igp/5598/5598_113.zip

 

There appear to be two relevant files, SIS597M.DRV and SIS597M.VXD.

The Win95 and Win98 versions of the former are identical, whereas the

two VXD files are the same size and version, but have different

contents.

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest MEB]

Re: No IRQ for graphic card in Windows 95

 

Sorry Franc, attending to other things and went on a short trip,,, will

look at the info once I get caught up on the mail and groups.....

 

--

MEB

http://peoplescounsel.orgfree.com

--

_________

 

 

 

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:ppjm94dea1t5moqjef1fl7ena2ib86n6vg@4ax.com...

| On Thu, 07 Aug 2008 15:32:48 +1000, Franc Zabkar

| <fzabkar@iinternode.on.net> put finger to keyboard and composed:

|

| >I just checked my old Win95B backups for my current socket 7

| >motherboard (M571, PCChips). There is no IRQ assigned to the onboard

| >VGA (SiS 5597/5598). However, the same hardware under Win98SE *does*

| >get an IRQ. Unfortunately I can't be certain whether "assign IRQ to

| >onboard VGA" was enabled in the BIOS in both instances.

|

| Just checked my BIOS again. The option is actually to "assign IRQ to

| PCI VGA". There is no such option for the onboard VGA, so it does look

| like Win95 doesn't assign an IRQ to the graphics card.

|

| The drivers are here:

| http://driver.sis.com/graphic/igp/5598/5598_113.zip

|

| There appear to be two relevant files, SIS597M.DRV and SIS597M.VXD.

| The Win95 and Win98 versions of the former are identical, whereas the

| two VXD files are the same size and version, but have different

| contents.

|

| - Franc Zabkar

| --

| Please remove one 'i' from my address when replying by email.

[Guest MEB]

Re: No IRQ for graphic card in Windows 95

 

Like I said, a long time ago, but I seem to remember some issues with VLB.

 

Lost Colors with Cirrus Logic Based VLB Video Adapter

http://support.microsoft.com/kb/119874

 

But personally, seems there WAS some sort of issue with the IRQ [seems like

it was 9 on most video adapter boards when enabled], in addition to the

issues when mixed with PCI slots [as indicated above]. As for the on-boards

I can't remember... however, a tidbit of memory seems to indicate what you

placed elsewhere, the IRQ wasn't really that necessary as the VLB design

addressed in a different fashion.

 

Couldn't get to the driver for some reason...

 

There were a few discussion groups on tweaker forums related to the VLB

cards/chips, not sure if any would still pop-up, might try over on

http://www.vintage-computer.com/ or the archives on Tom's Hardware.

 

--

MEB

http://peoplescounsel.orgfree.com

--

_________

 

 

 

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:ppjm94dea1t5moqjef1fl7ena2ib86n6vg@4ax.com...

| On Thu, 07 Aug 2008 15:32:48 +1000, Franc Zabkar

| <fzabkar@iinternode.on.net> put finger to keyboard and composed:

|

| >I just checked my old Win95B backups for my current socket 7

| >motherboard (M571, PCChips). There is no IRQ assigned to the onboard

| >VGA (SiS 5597/5598). However, the same hardware under Win98SE *does*

| >get an IRQ. Unfortunately I can't be certain whether "assign IRQ to

| >onboard VGA" was enabled in the BIOS in both instances.

|

| Just checked my BIOS again. The option is actually to "assign IRQ to

| PCI VGA". There is no such option for the onboard VGA, so it does look

| like Win95 doesn't assign an IRQ to the graphics card.

|

| The drivers are here:

| http://driver.sis.com/graphic/igp/5598/5598_113.zip

|

| There appear to be two relevant files, SIS597M.DRV and SIS597M.VXD.

| The Win95 and Win98 versions of the former are identical, whereas the

| two VXD files are the same size and version, but have different

| contents.

|

| - Franc Zabkar

| --

| Please remove one 'i' from my address when replying by email.

[Guest Franc Zabkar]

Re: No IRQ for graphic card in Windows 95

 

On Tue, 12 Aug 2008 02:54:41 -0400, "MEB" <meb@not here@hotmail.com>

put finger to keyboard and composed:

>Like I said, a long time ago, but I seem to remember some issues with VLB.

>

>Lost Colors with Cirrus Logic Based VLB Video Adapter

>http://support.microsoft.com/kb/119874

 

There is nothing wrong with the adapter except that it occasionally

powers up with a strange "pixellation" issue. A hardware reset usually

cures this. Other adapters with the same chipset have the same

problem.

 

I did once have a colour problem, but that turned out to be an open

inductor in one of the RGB outputs. This prevented the card from

seeing the corresponding 75 ohm termination resistor in the monitor,

which then caused the CL chip to revert to monochrome mode.

> But personally, seems there WAS some sort of issue with the IRQ [seems like

>it was 9 on most video adapter boards when enabled], in addition to the

>issues when mixed with PCI slots [as indicated above]. As for the on-boards

>I can't remember... however, a tidbit of memory seems to indicate what you

>placed elsewhere, the IRQ wasn't really that necessary as the VLB design

>addressed in a different fashion.

>

> Couldn't get to the driver for some reason...

>

> There were a few discussion groups on tweaker forums related to the VLB

>cards/chips, not sure if any would still pop-up, might try over on

>http://www.vintage-computer.com/ or the archives on Tom's Hardware.

>

>--

> MEB

> http://peoplescounsel.orgfree.com

 

I originally had a black screen problem with the S3 PCI card.

Reseating it seems to have fixed it. It was only while troubleshooting

this adapter that I noticed its open IRQ jumper. Curiosity prompted me

to find out if the card would behave any differently with the jumper

installed. It seems that it is not really needed, at least not for

word processing.

 

- Franc Zabkar

--

Please remove one 'i' from my address when replying by email.

[Guest MEB]

Re: No IRQ for graphic card in Windows 95

 

 

 

 

 

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message

news:ade6a45g3ct9fq1no6082322i3je2jlq46@4ax.com...

| On Tue, 12 Aug 2008 02:54:41 -0400, "MEB" <meb@not here@hotmail.com>

| put finger to keyboard and composed:

|

| >Like I said, a long time ago, but I seem to remember some issues with

VLB.

| >

| >Lost Colors with Cirrus Logic Based VLB Video Adapter

| >http://support.microsoft.com/kb/119874

|

| There is nothing wrong with the adapter except that it occasionally

| powers up with a strange "pixellation" issue. A hardware reset usually

| cures this. Other adapters with the same chipset have the same

| problem.

 

Well, I do remember difficulties with the VLB format, in that it was

difficult at times to get good connections via the slot. But if your's is

on-board I'd think maybe the connector cable was going bad or one of the pin

connections might be loose. I get that even today with this monitor... the

dang cable stresses the connections and either breaks the soldered joints

[generally IN the monior], or the pins expand causing intermittent issues.

Right now its decided to darken one side (right) while there is a "bleed" of

light stripes from dark colors like black to the right... ah well, some day

I might actaully fix it again.

 

|

| I did once have a colour problem, but that turned out to be an open

| inductor in one of the RGB outputs. This prevented the card from

| seeing the corresponding 75 ohm termination resistor in the monitor,

| which then caused the CL chip to revert to monochrome mode.

 

OH yeaaaah, had issues like that on occasion.

 

|

| > But personally, seems there WAS some sort of issue with the IRQ [seems

like

| >it was 9 on most video adapter boards when enabled], in addition to the

| >issues when mixed with PCI slots [as indicated above]. As for the

on-boards

| >I can't remember... however, a tidbit of memory seems to indicate what

you

| >placed elsewhere, the IRQ wasn't really that necessary as the VLB design

| >addressed in a different fashion.

| >

| > Couldn't get to the driver for some reason...

| >

| > There were a few discussion groups on tweaker forums related to the VLB

| >cards/chips, not sure if any would still pop-up, might try over on

| >http://www.vintage-computer.com/ or the archives on Tom's Hardware.

| >

| >--

| > MEB

| > http://peoplescounsel.orgfree.com

|

| I originally had a black screen problem with the S3 PCI card.

| Reseating it seems to have fixed it. It was only while troubleshooting

| this adapter that I noticed its open IRQ jumper. Curiosity prompted me

| to find out if the card would behave any differently with the jumper

| installed. It seems that it is not really needed, at least not for

| word processing.

|

| - Franc Zabkar

| --

| Please remove one 'i' from my address when replying by email.

 

--

MEB

http://peoplescounsel.orgfree.com

--

_________