[SGVLUG] Bad memory in Pentium I, HD too large, PC power use

[Dustin Laurence]

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David Lawyer wrote:

| About 4 years ago I decided to update my Pentium I PC with new
| memory.  I got 2@ 64 MB EDO modules and they worked fine.  Then I
| stopped using the PC due to excessive RF radiation

I think I'm *not* going to ask how you noticed this.

| ....So I installed a used power supply from a 486 PC.
| I found the PC was frequently crashing but this stopped when I
| replaced the newer EDO memory with slower "fast paged memory) from an
| older Pentium I PC. Then I returned the 2@ 64 MB of memory for
| replacement

Didn't it occur to you that the problem looks like the 486 PS is
marginal for the Pentium? I don't know what the failure modes are, but
putting a PS from a 486 into a 586 box seems a priori risky. Even if the
overall output is adequate, does your 586 MB draw the same proportion
off, say, the 5V rail and the 12V rail? It doesn't have to, and each
voltage supply has its own limit. For that matter, does the 586 need
cleaner power than the 486? It doesn't seem that unreasonable.

I don't actually know if a motherboard with an overstressed PS might
have such a failure mode, but the fact that the memory worked fine until
you swapped out the PS's makes it seem  more likely.

Anybody actually know if an overstressed PS has such a failure mode?

but my first try at this didn't work since I accidentally
| returned 2@ 8 MB of memory.  They sent me new memory but it has the
| same problem as what I returned:  It frequently crashes.
|
| Except if I also (in addition to the new 2 @ 64 MB) install say 2@ 8MB
| of fast paged memory (older and slower then EDO)  everything is OK and
| it doesn't crash. Boot time is perhaps 10% longer.   I guess the
| slower memory in bank 2 slows down the newer EDO memory in bank 1 and
| thus it doesn't fail and cause crashes.  It this correct?

I'd guess so. But my guess is that the problem is the whacky PS swap,
and that's where you have to go to solve the problem.

| So now I need some memory for my other Pentium 1 (I'm using as a
| backup) due to the loss of 2@ 8MB I accidentally mailed.  Is it easy
| to find locally or do I need to ask OEMPC World in San Jose, where I
| ordered my replacement memory from, to return it (after I said they
| could keep it).  More than 8 MB would be even better.  It can be
| either EDO or FPM.  I'll bet people are throwing away PC's with such
| memory in them.

Yes. But...if you go to buy it, you'll probably find the prices at
easy-to-find places are silly. The price of memory modules doesn't seem
to drop much once it is more than a few generations old.

| Re the HD too large problem,

There is no such thing as a drive too large, only a data collection too
small. :-)

You'll no doubt be interested to know that I am stress-testing a new
500Gb drive as we speak; it isn't cost effective to buy anything smaller
than 500Gb at the moment, and I think the best deal I saw was on a 750
Gb drive (after I'd bought the 500...). Terabyte drives are now high-end
mainstream, so it won't be long before a $200 Wal-Mart special has a
terabyte drive because the OEM couldn't find anything cheaper. :-)

OK, actually, that might very well not happen, depending on where the
price of solid-state drives goes. They might just start putting 100Gb
flash cards (essentially) in them instead.

Just a taste of what the wicked world outside is doing.

| ...I decided to upgrade my hard drive and
| bought a used 40 GB HD to replace a bad 3 MB HD which sometimes causes
| the power supply shutdown.  My MB (ATC 5000 from 1999) can't recognize
| it and I found complaints about this on the Internet.  Even though the
| BIOS has LBA for the HD, supposedly able to access 4 TB of disk,  40
| GB is too much for it!   On the Internet, they said that even flashing
| the BIOS with an update fails to fix this problem.

It's *just* *possible* that the universe is trying to tell you something
there. :-)

| My PC is fast on the Inherent

My ISP doesn't provide Inherent access. :-)

| ...with either the Lynx (text only) or
| Dillo browsers.

I have a 6502-based C-64 in the garage that would probably be just your
ticket. :-)

| ...Unfortunately, neither is being updated and they do
| need updating,

Dillo isn't being maintained? That's sad. Anyway, I think links2 is the
current preferred text-mode browser, you might try it instead of good
old lynx.

I'm in favor of low energy PC's, like my 486 that per
| the manual uses 16 watts in full power mode and 11.5 watts in green
| mode.

I just don't believe that number. I think they put ~>230W PSs in 486s.
In any case, supplies that old are *very* inefficient compared to new
ones, so whatever you're getting could be gotten far more efficiently
with modern hardware and efficient power.

Anyone want to start a fund to buy David a Gumstix or Soekris board so
he can build a box that runs on (probably, esp. for the Gumstix) a few
hundred milliwatts? Not *that's* my kind of low-power.

OK, time for me to put on the red and white striped shirt, white pants,
and straw hat that every true huckster wears and have some fun, because
I have the deal for you and I'm in a whimsical mood.

Anyway, David, today is your lucky day, because I've been cleaning out
my boxes of ancient hardware to try to use what can be assembled into
actual running gear and toss everything else. I happen to have the kind
of gear you, and only you, dream about in my "must throw away or I have
no room for new toys" box: memory SIMMs, including some 8 Mb sticks that
I just yesterday personally tested in *my* ancient Pentium, and maybe
even some 16 Mb sticks. Some is FP, too. I managed to find enough to
cram 96 Mb in the Pentium box, and I think there is enough left to fill
another board with 48 or 64 Mb (assuming four memory slots, as I have).
I think Pentia (what else could be the plural of Pentium? Pentiumim, I
guess, if we go with Hebrew instead of Latin) need matched memory pairs,
but fortunatly almost everything is in fact in pairs.

Come to think of it, I didn't have little conductive bags to keep them
separated by type, so they are in ziplocs. They may get fried by static
electricity if not given another home.

"Ancient memory modules made with stone knives out of bearskins is well
and good," you might be thinking; "but what about mass storage? I don't
want to have to go back to chiseling bits onto stone tablets." I feel
your pain, BUT WAIT, THAT'S NOT ALL! I have a small stack of ancient
drives in the 4-5 Gb range, plus an antediluvian 1.2 Gb specimen that
came originally from a 486--enough to cram 15 or 20 Gb onto the four
controllers on your board (it should be happy with multiple 5 Gb drives,
but four drives consume more power than one--what a dilemma).

There is a 100Mb zip and a 1Gb jaz (remember *those*?) drive in there
with disks, but they're SCSI so you'd have to have a card to use them. I
won't mention the 500 Mb outboard SCSI--it is tiny and probably draws as
much power on its own as your computer.

Power supply a problem?  I have an old 230W (I think) power supply--the
connector is some odd 24-pin thing but I was assured that the pinout of
the first 20 is identical to that of a regular PC supply (but would
definitely need checking with a multimeter, lest we smoke a board). I
can't say if it will agree with your board, but it is for a later
computer and that's a better bet than one from an earlier computer. If
you can stand the thought of wasting *so much power*, there is also a
P-II board and CPU in there that I was told works. I may not have any
memory that will fit it though (most or all of the 168-pin memory I had
went into the P-II that is still soldiering away with 128 Mb or so as my
little server). Most of a computer, in other words, if you have a spare
ATX box somewhere.

"Well, OK," you're probably thinking. "I can see how that would do just
nicely for my fine collection of pirated movies off the Internet, er,
the Inherent--I only need to save a couple of frames from each of them
after all (which is all I'll have room for on those itty-bitty disks).
But what about communications? Smoke signals are against the fire code,
and IP-over-homing-pigeon requires I keep a lot of messy birds. What can
you do about that?" Well, again, the Box-O-Ancient-Secrets has something
for you. I have some spare NICs, probably ISA, probably 10 Mb, but maybe
more, and at least one modem card (I think it's a winmodem though, so I
can't say if it's supported), and probably something else. The 586 and
P-II boxes already have plenty of NICs, I think.

Anyway, the fate of this stuff is likely to be tossed or disassembled to
find magnets for Eric, but all this and more (ancient ISA floppy
controllers from a 486, for example) can be yours, but probably you'd
have to show up to a meeting to pick it up. "Frankenstein David's box"
party, anyone?

You'll probably also have to put up with the fact that I think a great
many of your theories are whacky. :-) But that doesn't mean you can't
give a bunch of lonely parts one more pass at the brass ring.

In spite of the whimsy, the offer of gear is entirely serious. It's
free, unless you have an old Sun three-button mouse, in which case I'll
trade you for a mouse for the UltraSPARC (which, come to think of it, is
probably about the equivalent of a 486). :-)

Dustin
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