8 May
2002
8 May
'02
8:38 a.m.
On May 8, 15:24, Robert F Schaefer wrote:
I'll spend a little more time looking into that.
I believe the ealier
PIs
take standard parity SIMMs, but I thought the 4D/35s
take a differrent
SIMM
from everything else. Be nice if I could bump them up
to 8 MB.
Yes, the early PI's take standard 30-pin SIMMs.
To upgrade Indigo 4MB SIMMs, you need to find eight 514400 (or equivalent)
80ns DRAMs in 26/20-pin SOJ package, and eight SMD decoupling capacitors
(sorry, don't remember the value but such caps are usually about
100-200nF). The capacitors are fitted in positions marked C3, C4, C8, C9,
C12, C13, C17, C18 on the DRAM side, before the DRAMs (which cover them).
I thought I remebered changing a resistor on the other side (ASIC side) but
I just compared a 4MB to an 8MB, and they have the same resistors, so I
must have been thinking of something else.
--
Pete Peter Turnbull
Network Manager
University of York
8 May
8 May
9:46 a.m.
----- Original Message -----
From: "Pete Turnbull" <pete(a)dunnington.u-net.com>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, May 08, 2002 04:38 PM
Subject: Re: IRIX on Personal Iris
On May 8, 15:24, Robert F Schaefer wrote:
Sounds easy enough. Now all I need to do is find someone with an SMD rework
station. ^_^ This'd be a good time to see about upgrading my SPARCBook2 to
64MB too.
I'll spend a little more time looking into
that. I believe the ealier
PIs
take standard parity SIMMs, but I thought the
4D/35s take a differrent
SIMM
from everything else. Be nice if I could bump
them up to 8 MB.
Yes, the early PI's take standard 30-pin SIMMs.
To upgrade Indigo 4MB SIMMs, you need to find eight 514400 (or equivalent)
80ns DRAMs in 26/20-pin SOJ package, and eight SMD decoupling capacitors
(sorry, don't remember the value but such caps are usually about
100-200nF). The capacitors are fitted in positions marked C3, C4, C8, C9,
C12, C13, C17, C18 on the DRAM side, before the DRAMs (which cover them).
I thought I remebered changing a resistor on the other side (ASIC side)
but
I just compared a 4MB to an 8MB, and they have the
same resistors, so I
must have been thinking of something else.
PS/2 SIMMs?
--
Pete Peter Turnbull
Bob
11:28 a.m.
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1:13 p.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Wednesday, May 08, 2002 07:28 PM
Subject: Re: IRIX on Personal Iris
> > To upgrade Indigo 4MB SIMMs, you need to
find eight 514400 (or
equivalent)
> > 80ns DRAMs in 26/20-pin SOJ package, and
eight SMD decoupling
capacitors
> > (sorry, don't remember the value but
such caps are usually about
> > 100-200nF). The capacitors are fitted in positions marked C3, C4, C8,
C9,
> > C12, C13, C17, C18 on the DRAM side, before
the DRAMs (which cover
them).
>
> Sounds easy enough. Now all I need to do is find someone with an SMD
rework
> station. ^_^ This'd be a good time to see
about upgrading my
SPARCBook2 to
For something like this you could probably use a fine-tipped soldering
iron and fine silver-loaded solder. You'll have to work slowly and
carefully, but SMD soldering is possible with normal hand tools...
The next time I have the 4D/35 open, I'll pull a SIMM and stare at it for a
while. If it's just the fine pitch of the leads I feel pretty confident,
but the chip spacing on the SB2 CPU board is on the order of .5 mm. I don't
think I can get a soldering iron onto the bottom of the j-leads in between
the chips.
There's an article in this month's Circuit Cellar (is there anyone here
who _doesn't_ read that?) on doing SMD rework (removing and replacing a
TQFP chip) using a soldering iron, etc. The methods described are roughly
what I use, and they do work (no I am not claiming I invented them -- I
read about them somewhere, but I've forgotten where. I am certainly not
claiming that the author of this article has 'stolen my ideas').
I'll look it up.
-tony
Bob
8311
days inactive
8311
days old
3 comments
3 participants
participants (3)
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ard＠p850ug1.demon.co.uk -
pete＠dunnington.u-net.com -
rschaefe＠gcfn.org