31 Jan
2006
31 Jan
'06
5:32 p.m.
What this sounds like is that he wants something to build up a (say) 128 MB SIMM from 4 32
MB SIMMS, and have it be the same width. This sounds suspiciously like you're trying
to build a device to create a composite SIMM, which does require some external logic
(often implemented as a PAL). When composite SIMMS were made, they were the cause of some
"profanity sculpture", as they tended to not have consistant timing, if I
recall. The 8-bit to 32-bit adaptors were/are fairly common, but with 4-16 MB 32/(36)bit
SIMMS free to very cheap, not really worth pursuing.
31 Jan
31 Jan
5:46 p.m.
In article <5a7e0ed1ec36401c8d0d5867a7e6a0ec at valleyimplants.com>,
compoobah at valleyimplants.com writes:
[...] but with 4-16 MB 32/(36)bit SIMMS free =
to very cheap, not really worth pursuing.=0D=0A
Hey, if you've got 16 MB 32-bit SIMMs laying around, I may have a use
for them in these IBM 300XL, 350 and 365 machines I just got from
work. I'm trying to coagulate the various parts of a group of systems
into a single system to get them a little beefier before I give them
away to interested parties. It would be nice to get them all up to 64
MB at least before shipping them out.
Is there an easy way to spot the size of the SIMM? I don't have chip
numbers memorized.
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"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
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1 Feb
1 Feb
9:10 a.m.
Richard asked:
Is there an easy way to spot the size of the SIMM? I
don't have chip
numbers memorized.
Now there's a question I'd like to see answered with a website.
Keeping the SIMM (and other boards) "closed coded" so that only inner
circle suppliers can deal with them intelligently seemed to be the
motivation.
Chip numbers are probably the only sure way out, many of us could use
a www table for that.
John A.
10 a.m.
In article <009b01c62752$6c44fd60$5f25fea9 at ibm23xhr06>,
"John Allain" <allain at panix.com> writes:
Chip numbers are probably the only sure way out, many
of us could use
a www table for that.
Probably the best way to collect that information is to edit this page
on wikipedia: <http://en.wikipedia.org/wiki/SIMM>
--
"The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ:
<http://www.xmission.com/~legalize/book/>
Pilgrimage: Utah's annual demoparty
<http://pilgrimage.scene.org>
10 Feb
10 Feb
11:32 p.m.
Wow, January 31. Due to the talk-to-tech delay, this might have been
answered already, but here goes...
Is there an easy way to spot the size of the SIMM? I
don't have chip
numbers memorized.
For 72 pin SIMMS, the installed jumper (0 ohm) resistors usually tell
the story on size and speed.
The key I have says jumpers J1 and J2 are the size. J3 and J4 are the speed.
..00 60ns
..10 70ns
..01 80ns
..11 50 or 100ns.
00.. 8MB
10.. 1MB or 16MB
01.. 2MB or 32MB
11.. 4MB or 64MB
If there are only two jumpers on your SIMM it's probably a 60ns SIMM.
You can usually guess whether it's parity or not by chip count.
If pin 19 is connected, it's probably the larger of the two options.
I don't know how to identify smaller SIMMS (128K and 512K 72-pin SIMMS
apparently existed, Maybe J0 and J5 which are identified in some data
sheets, but I've never seen a SIMM with jumpers for them.)
For 30 pin SIMMS you'll probably need to look at the chips. Most of
the time there's an obvious sign of the size (a 256 or 512 in the part
number.)
31 Jan
31 Jan
7:11 p.m.
The 8-bit to 32-bit adaptors were/are fairly common,
but with 4-16 MB
32/(36)bit SIMMS free to very cheap, not really worth pursuing.
I'm not sure. I thought of an unconventional use for one the other
day. A friend had five 16M 30-pin SIMMs and knew that of four of them,
one was bad, but didn't know which one.
It occurred to me that putting them a 30-to-72 adapter could end up
getting them into a machine with more thorough memory-test
capabilities, and which byte lane errors appeared in would tell which
of the four was at fault. (In principle, you could do as much with a
machine that took 30-pin RAM directly. But if the memory-test
capabilities you have on such machines aren't up to what you have on a
72-pin machine....)
Yes, it's admittedly a rather recondite use. :-)
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5 comments
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participants (5)
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allain＠panix.com -
compoobah＠valleyimplants.com -
korpela＠ssl.berkeley.edu -
legalize＠xmission.com -
mouse＠Rodents.Montreal.QC.CA