david@cwlim.INS.CWRU.Edu (11/29/89)
Why do AT&T machines always seem to be at the heart of the trouble?
I have (I had no choice in the matter) AT&T 6386 20Mhz machine for
my Novell file servers. That might not be so bad in a normal situation,
but who's network is even remotly normal? Anyway, I have had to put
more then one meg of RAM in each machine. Presently, I have two Meg in
one and four Meg in three others. My machine with two Meg has decided
to lock up on a regular basis--cause: presumed memory.
Two of the three machine with four Mag have it in 256k SIMMS, so the
card is full, and there is no expansion room and no trouble. Well,
I decided to put one Meg SIMMS in a servers to give it four meg with
expansion room. The memory has appeared to be totally compatable, it
is 9 chips of 80 ns. Macs love it (the only SIMM tester I have) but,
the AT&T machine don't. With 12 one meg SIMMS, I was only able to get
four to work in the AT&T machines. The other would not allow the
machine to boot, for that matter, they couldn't even pull up a display
or reset the keyboard (the three lights remain on.) I have also noticed
that the settings I have gotten the card and memory to operate with,
whether 256k SIMMS or 1 Meg SIMMS, unless there is the standard four
256k SIMMS, the switch setting on the card do not match the book. I don't
get it. I need to put some AT&T CERTIFIED memory in my file servers and
I don't know how to set the card to match the book and have the machine
operate. I don't care at this point if I have to pay more then the
going rate to get proven AT&T 100% reliable memory, preferablly in
four meg SIMM modules. Any information, help, or other information
anyone can provide would be greatly appreciated to the Nth degree.
Thank you.
Dave
david@cwlim.ins.cwru.edu dwn@pyrite.som.cwru.edu
P.S. I have notice some stand alone computers (the same internals) with
one Meg straight from the warehouse have the same trouble booting.
I suspect memory. Perhaps a timing problem? gpw@cbnewsc.ATT.COM (george.p.wilkin) (11/30/89)
From article <918@cwjcc.CWRU.Edu>, by david@cwlim.INS.CWRU.Edu: > Why do AT&T machines always seem to be at the heart of the trouble? > > I have (I had no choice in the matter) AT&T 6386 20Mhz machine for > my Novell file servers. That might not be so bad in a normal situation, > but who's network is even remotly normal? Anyway, I have had to put > more then one meg of RAM in each machine. Presently, I have two Meg in > one and four Meg in three others. My machine with two Meg has decided > to lock up on a regular basis--cause: presumed memory. The AT&T memeory board do NOT all support 1meg chips! Some boards will ONLY support 256K chips. This is how I have surmized the distribution of board types: 908 915 = 16Mhz 256K only 917 = 20Mhz 256K only 916 = 16Mhz 1meg or 256k 922 = 20Mhz 1meg or 256k 925 = 20Mhz 1meg or 256k Again I THINK this is how they break out I AM NOT an OFFICIAL SOURCE!! Can you put 1 meg chip into the earlier boards, maybe. Will AT&T support anything other than their board? My guess, based on attempts such as yours, is no. What's different?? The first mask had some faults(I was able to match boards by 'correcting' them myself, of course voiding any warr.) and there are a number of 'white' wire changes. I also noticed that the 20Mhz machines and the 16Mhz machines have different PALs in them(this is just on the Memory board) and that some of the new boards have different PAL IDs. How will I fix things to work? Compare the working machines.... check PALs etc check board types(on a yellow tag and also on the mask) to see which ones are working. Swap working boards into non-working systems. see if they come up.. A board that will not work in ANY system is one thing, one that works i 3 out of five is another. Ask AT&T to fix them, Scream, kick yell....You have a 50-50 chance of getting a new board install that WILL support 1 meg simms. BTW I have found that under UNIX(a little r goes here) there can,(might) be problem with core dumps if your memory board is too far out of sync with your motherboard(ie. 908 memory board in a newer machine) so watch what kind of replacement boards you get. gpwilkin Of course I don't speak for AT&T, just myself. -- George Wilkin AT&T Network Systems,(IH MAIN BL) 2000 N. Naperville Rd. Rm IH4A157 Naperville, IL. 60566-7033 att!ihlpf!gpw work ph# (312) 979-4317
fmcgee@cuuxb.ATT.COM (~XT6561110~Frank McGee~C23~L25~6326~) (12/03/89)
In article <918@cwjcc.CWRU.Edu> david@cwlim.INS.CWRU.Edu () writes: >Why do AT&T machines always seem to be at the heart of the trouble? > >I have (I had no choice in the matter) AT&T 6386 20Mhz machine for >my Novell file servers. That might not be so bad in a normal situation, >but who's network is even remotly normal? Anyway, I have had to put >more then one meg of RAM in each machine. Presently, I have two Meg in >one and four Meg in three others. My machine with two Meg has decided >to lock up on a regular basis--cause: presumed memory. >Two of the three machine with four Mag have it in 256k SIMMS, so the >card is full, and there is no expansion room and no trouble. Well, >I decided to put one Meg SIMMS in a servers to give it four meg with >expansion room. The memory has appeared to be totally compatable, it >is 9 chips of 80 ns. Macs love it (the only SIMM tester I have) but, >the AT&T machine don't. With 12 one meg SIMMS, I was only able to get I'd count the chips on your SIMMs again. Macs use 1 Meg x 8 SIMMs, not 1 Meg x 9 like the 6386. I suppose if you stuck 1 Meg x 9's in Mac the Mac would ignore the extra parity bits though. As someone already pointed out, there are some early versions of the AT&T memory cards that can't support 1 Meg SIMMs. Believe it or not, the easy way to tell if your card does is to look at the slot cover. Cards that support 1 Meg SIMMs have holes in the slot cover. The holes are there to help dissipate all the heat created by 16 1 Meg SIMMs. There are also 120 ns versions of the card (for the 16 Mhz. machines) and 100 ns. versions of the card (for the 20 Mhz. machines). Make sure you aren't trying to use a 120 ns. card in a 20 Mhz. machine; I've run into this one before with customers that have both types of machines. As for dip switch settings, I can pull up a few cheat sheets on how to set them, and if enough people email me asking for them I can repost them (they were posted here some time ago). As for AT&T certified memory, the only AT&T certified memory is the memory sold by AT&T. You're looking for PEC 37716, it sells for $2900 U.S. list; it is 4, 1 Meg x 9 SIMMs. However, at our site here we've been using Toshiba SIMMs (THM91000S-10) without any problems. Hope this helps you out, -- Frank McGee, AT&T Tier 3 Complementary Channel Sales Support attmail!fmcgee