[comp.sys.ibm.pc.hardware] Upgrading 286 to 386

grim2@cbnewsk.att.com (steven.j.pilgrim) (01/10/91)

I would appreciate any help I can get with this relatively
basic question.  How difficult is it to upgrade a 286-12
machine to something more powerful like a 386-25 or 386-33?
I'm not a hardware guru.  I've put in cards and changed jumpers
on the motherboard for different video display settings but
that's about it.  I'm not afraid of taking it apart on the other hand.
I have a large footprint Northgate 286-12.  The only extra
internal cards I have are a mouse card, VGA card, modem, and
a joystick card.  The disk controller is an RLL type.  I have
your basic three drives.  I've read some articles here that
say I should consider a 16-bit disk controller if I move up
in speed.  My basic questions are what do I need to look for
when making a purchase through Computer Shopper for instance?
Northgate does not sell motherboards separately so I will need
to go to a different vendor.  How can I tell if I will need to
upgrade my disk controller?  Is this something someone with my
limited experience can handle?  One other question.  Since I
don't want to do this procedure too often does getting a cache
on my system make sense?  How much memory is usuallly needed
these days on the motherboard the applications coming out these
days?  Like I said, any help/insight you can provide is appreciated.
Hopefully I can learn something to help someone else sometime.

Thanks,
Steve Pilgrim

vandevek@fergvax.unl.edu (James M. VandeVegt) (01/20/91)

In article <1991Jan9.185040.7909@cbnewsk.att.com> grim2@cbnewsk.att.com (steven.j.pilgrim) writes:
>I would appreciate any help I can get with this relatively
>basic question.  How difficult is it to upgrade a 286-12
>machine to something more powerful like a 386-25 or 386-33?
>I'm not a hardware guru.  I've put in cards and changed jumpers
>on the motherboard for different video display settings but
>that's about it.  I'm not afraid of taking it apart on the other hand.
>I have a large footprint Northgate 286-12.  The only extra
>internal cards I have are a mouse card, VGA card, modem, and
>a joystick card.  The disk controller is an RLL type.  I have
>your basic three drives.  I've read some articles here that
>say I should consider a 16-bit disk controller if I move up
>in speed.  My basic questions are what do I need to look for
>when making a purchase through Computer Shopper for instance?
>Northgate does not sell motherboards separately so I will need
>to go to a different vendor.  How can I tell if I will need to
>upgrade my disk controller?  Is this something someone with my
>limited experience can handle?  One other question.  Since I
>don't want to do this procedure too often does getting a cache
>on my system make sense?  How much memory is usuallly needed
>these days on the motherboard the applications coming out these
>days?  Like I said, any help/insight you can provide is appreciated.
>Hopefully I can learn something to help someone else sometime.
>
>Thanks,
>Steve Pilgrim
What you already have done is the right idea except you have to go
deeper.  Assuming that the new MB fits correctly in your case and power
supply, take out all your cards, unscrew the motherboard, put the new MB
in, and replace the cards.

I leave the HD controller to someone with more expertise.  It would be
my suggestion to upgrade to 16-bit archetecture whether the current one
runs or not.

As far as memory SRAM caches are concerned, more is better but it is
also more expensive given the price of SRAM.  I have seen 32K and 64K
advertised frequently, but as high as 256K.  I would probably go with a
64K cache on a 386-25 or 386-33.  You find very few memory cache units
with the 20MHz chip.  And, if you are thinking about putting in a 20MHZ,
put in a 25MHZ without cache instead, you will get better performance
without too much more money.

I am not sure if you are asking about conventional memory or not, but
get at least 4 Meg in 1Mx9 SIMMS.

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| James M. VandeVegt             |  University of Nebraska           |
| vandevek@fergvax.unl.edu       |  Computer Science and Engineering |
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