trh@arizona.UUCP (05/14/87)
It's tax refund time and I am thinking of upgrading my PC7300.
I am wondering about doing the work myself and am polling the
net for sagacious advice.
1) Has anyone out there done their own memory upgrade either on
the motherboard or the 500k RAM card?
It seems as if one could just cut out the old chips,
carefully remove the legs, etc, etc...
What I really worry about, though, is that some resistor or
capacitor value would have to be changed, or some point-to-point
wiring change would be necessary and I wouldn't know it.
Anyone know anything about this?
2) What half-height 40M hard disks are spacially and electrically plug
compatible?
I would like to just "drop" a new disk in place. How about
the new Seagate 251 drives? Anyone have experience with these?
3) If I just increase the memory, will I find more disk space used
as swap space, or is the usage unrelated to real memory?
Finally, if I don't do it myself,
4) What are the current prices for upgrades from places such as
Amperfax Corp?
Thanks (optimistically) in advance for any and all info.
-Tom Hicks
trh@arizonamark@gizzmo.UUCP (05/15/87)
In article <2069@arizona.edu> trh@arizona.edu (Tom Hicks) writes: > > It's tax refund time and I am thinking of upgrading my PC7300. >I am wondering about doing the work myself and am polling the >net for sagacious advice. I WOULDNT SUGGEST DOING THIS AS ATT HAS MODIFIED THE VARIOUS MODELS OF THE 7300 WITH CUT RUNS, STRAPS AND OTHER NASTY STUFF TO ALTER THE WAY MEMORY WORKS. THERE HAVE BEEN HORROR STORIES ABOUT PEOPLE TRYING TO DO THIS MOD AND PAYING $2600 FOR A NEW ONE. ALSO I MUST MENTION THAT THE BOARD ARE MULTI-LAYER, AND THAT UNLESS YOU HAVE BEEN TO A NASA SOLDERING SCHOOL THAT YOU CAN REALLY MESS UP THE BOARDS WITHOUT EVEN KNOWING SO. CALL AMPERFAX AND THEY WILL GIVE YOU LOTS OF DOCUMENTATED CASES WITH PHONE NUMBERS. >2) What half-height 40M hard disks are spacially and electrically plug > compatible? Every drive that has a ST506 or ST412 interface is electrically compatable. A half height has the same basic dimsensions as every other half height. >4) What are the current prices for upgrades from places such as > Amperfax Corp? Call them! They will explain their total package and prices, I think that you will be impressed. TELL THEM WHERE YOU GOT THIS INFORMATION, IT WILL MAKE A DIFFERENCE!!!!! Their phone number is: 305-944-1477 ask for Andrew Cohen -- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ethos----------\ Mark Hilliard seismo!rochester!kodak!gizzmo!mark fthood---------/
dpw@unisec.usi.com (Darryl P. Wagoner) (05/16/87)
In article <2069@arizona.edu> trh@arizona.edu (Tom Hicks) writes: > > It's tax refund time and I am thinking of upgrading my PC7300. >I am wondering about doing the work myself and am polling the >net for sagacious advice. > >1) Has anyone out there done their own memory upgrade either on > the motherboard or the 500k RAM card? > It seems as if one could just cut out the old chips, > carefully remove the legs, etc, etc... > What I really worry about, though, is that some resistor or > capacitor value would have to be changed, or some point-to-point > wiring change would be necessary and I wouldn't know it. > Anyone know anything about this? This is one of the things that you don't do at home unless you are a pro at multi-layered PC boards. They are too easy to screw up. And if you do screw it up you will be out $2400+ bucks to replace it. It's not worth to save a few hundred bucks. >2) What half-height 40M hard disks are spacially and electrically plug > compatible? > I would like to just "drop" a new disk in place. How about > the new Seagate 251 drives? Anyone have experience with these? > I just installed a Seagate 251 in my Unix PC and I am very happy with it. The metal case around the disk drive will not fit. No big deal just leave it off. Also the screws that secure the drive that came off the Miniscript are to big for the ST 251. Find some more screws before you take your system apart. You can still hear the Seagate, but it sure is quieter than it was. >3) If I just increase the memory, will I find more disk space used > as swap space, or is the usage unrelated to real memory? No, swap is where the system saves the process info when it doesn't have room in memory. Therefore if you have more RAM memory then you will be using less swap space under the same conditions. I currently have 4 meg of swap space. I have yet to get any out of memory message from the system. This includes unpacking and uncompressing a full news feed with 3 users running different programs. At which point the five minute load aveage was over 2.00. -- Darryl Wagoner UniSecure Systems, Inc.; dpw@unisec.usi.com Newport, RI; (401)-849-0857 UUCP: {gatech|mirror|cbosgd|uiucdcs|ihnp4}!rayssd!unisec!dpw
cmv@ihuxz.ATT.COM (Craig Votava) (05/18/87)
About upgrading memory in your own 7300 In article <168@gizzmo.UUCP> mark@gizzmo.UUCP (mark hilliard) writes: > >I WOULDNT SUGGEST DOING THIS AS ATT HAS MODIFIED THE VARIOUS MODELS OF THE >7300 WITH CUT RUNS, STRAPS AND OTHER NASTY STUFF TO ALTER THE WAY MEMORY >WORKS. THERE HAVE BEEN HORROR STORIES ABOUT PEOPLE TRYING TO DO THIS MOD >AND PAYING $2600 FOR A NEW ONE. ALSO I MUST MENTION THAT THE BOARD ARE >MULTI-LAYER, AND THAT UNLESS YOU HAVE BEEN TO A NASA SOLDERING SCHOOL THAT >YOU CAN REALLY MESS UP THE BOARDS WITHOUT EVEN KNOWING SO. CALL AMPERFAX >AND THEY WILL GIVE YOU LOTS OF DOCUMENTATED CASES WITH PHONE NUMBERS. Sorry Mark, but I disagree with your statement! I too wanted to upgrade the memory in my 7300 and and called Amperfax to ask how difficult it is. They tried to scare me off with the same arguments that you've mentioned above. Then, I went to a group of veteran hardware guys here at Bell Labs and asked them what their opinion was. They said that you do have to be careful on multilayer boards, but it's no more difficult than desoldering on a single layer board. As far as strap changes and cut runs, I can't speak for all versions of the motherboard, but for mine (p3...p5) the change is simply a jumper change. I even have a copy of the instructions on how to do this that appears in a document published by Convergent themselves! My conclusion is that Amperfax is trying to get buisness (which is a valid thing for them to do) and so try and discourage folks from doing this. For me, their prices are too high for something I can do myself. Now, if your wondering how I can say all this, it's because I've recently taken a 0.5MB expansion board and ripped all the 64K chips out, installed sockets, and populated them with 256K chips. This took about 4 days, because I was so worried I'd screw up something, now I feel I could have done it in 2 easy days, or one work-hard day. After I did the hardware, I spent almost 3 weeks playing phone tag with the jerks at Convergent trying to figure out the jumper configuration (It's not the same on the expansion board as it is on the motherboard). When they did answer me, they gave me the wrong answer. Finally a very smart guy in AT&T figured it out and told me how it works. It takes 3 jumper wire changes... thats it! I now have a 2MB expansion memory board working in my unix-pc. I will be going after the motherboard sometime soon as my next project. If *ANYBODY* wants to do this, I will gladly send instructions/recommendations, etc. I would advise that you DON NOT take what you hear from amperfax as bible, and by the same token don't take what I say as bible either. Find a hardware guy that's knows his stuff and is familiar with you and ask his advice. I'll bet that you'll end up giving it a try too! I will be posting a detailed article in unix-pc.general as to how I did this. If you don't subscribe to this newsgroup, send me mail and I will gladly send you a copy! Craig Votava AT&T Bell Labs, Naperville IL IH 4G-324 x2542 {ihnp4!} ihlpm!cmv ih3b1!cmv