weird problem, adaptec 2940, pentium 133, triton II mb

weird problem, adaptec 2940, pentium 133, triton II mb

Post by Mark Philli » Mon, 19 Aug 1996 04:00:00



I've been runnin SCO Openserver 5 on a system with a Triton II MB
with 512K cache, a Pentium 75, and a 2gb Seagate disk on an adaptec
2940 host adapter.

Last week I decided to upgrade the processor to a 133mhz. I dropped
in the new CPU, changed two jumpers on the motherboard to indicate
the CPU was a 133, and rebooted.

All hell broke loose.

In a nutshell, it appears that SCO is attempting to retrieve data from
the host adapter faster than the host adapter can provide it. For instance,
I'll get read errors on files that I know are just fine (for instance, if
I attempt to re-link the kernel I'll get a "cannot read archive header from
.../pack.d/....". Other times the system will hang during the boot process,
or services will not start with various errors related to being unable to
read config files.

If I put the 75mhz chip back in, everything works fine.

Does anyone have any thoughts as to what my problem might be?

 
 
 

weird problem, adaptec 2940, pentium 133, triton II mb

Post by Dave Park » Mon, 19 Aug 1996 04:00:00



>I've been runnin SCO Openserver 5 on a system with a Triton II MB
>with 512K cache, a Pentium 75, and a 2gb Seagate disk on an adaptec
>2940 host adapter.

>Last week I decided to upgrade the processor to a 133mhz. I dropped
>in the new CPU, changed two jumpers on the motherboard to indicate
>the CPU was a 133, and rebooted.

>All hell broke loose.

>In a nutshell, it appears that SCO is attempting to retrieve data from
>the host adapter faster than the host adapter can provide it. For instance,
>I'll get read errors on files that I know are just fine (for instance, if
>I attempt to re-link the kernel I'll get a "cannot read archive header from
>.../pack.d/....". Other times the system will hang during the boot process,
>or services will not start with various errors related to being unable to
>read config files.

>If I put the 75mhz chip back in, everything works fine.

>Does anyone have any thoughts as to what my problem might be?

You might have to slow the bus speed down.  I don't know the particulars of
your motherboard, but some of the ones I've worked with recently have
selectable bus speeds of as high as (I believe) 66mhz.  The bus speed could
be less critical with a 75mhz chip, or you may have a board where the
jumpers that select the cpu speed also set the bus speed.  Either the TYAN
or the ASUS that I just worked with was that way.  I'm running a 100mhz
Pentium on that one (the ASUS, I think) at 90mhz because the bus speed
selections with the cpu speed set to 100mhz are too fast for the RAM (the
installation manual says I need 60ns SIMMs, I've got 70s).  
--


 
 
 

weird problem, adaptec 2940, pentium 133, triton II mb

Post by Bill Glicke » Tue, 20 Aug 1996 04:00:00


By any chance was this an adaptec 2940UW with a flashbios earlier than
1.23?  These had a memory management conflict with some Pentium
motherboards, which an upgraded bios might fix (it didn't fix it on mine).
Until you can get a bios upgrade, try disabling the external cache on the
motherboard (which did work for me).

Bill