lodman@ncr-sd.UUCP (Mike Lodman) (01/12/87)
Would someone please respond via e-mail and tell me what ram chips are needed to upgrade a 256K Zenith 158 PC to the full 640K? -- Michael Lodman Advanced Development NCR Corporation E&M San Diego sdcsvax!ncr-sd!lodman
tim@j.cc.purdue.edu.UUCP (01/13/87)
The Z-158 comes with one bank of 256K chips installed. There is room for two more banks of chips. Yes, this does give a total of 768K, but the ram decoder only sees the first 640K. Since the Z-158 can run at 8Mhz clock rate, 256K chips rated at 150ns or faster should be used. The Z-159 has the same configuration, but has no wait states for memory access. I do not know what speed the memory chips should be. -- Timothy Lange Purdue University Computing Center West Lafayette, IN 317-494-1787 extension 260 tim@j.cc.purdue.edu
reintom@rocky2.UUCP (Tom Reingold) (01/14/87)
Summary: Answer enclosed. References: <1294@ncr-sd.UUCP> In article <1294@ncr-sd.UUCP>, lodman@ncr-sd.UUCP (Mike Lodman) writes: > Would someone please respond via e-mail and tell me what ram chips > are needed to upgrade a 256K Zenith 158 PC to the full 640K? > -- > Michael Lodman To upgrade a Z-158 to 640K, you need to buy two more banks of 256K-bit chips to add to the one you have. A bank consists of nine chips. I believe you should get chips with a rating of 120ns to ensure proper operation at 8 MHz. A Zenith engineer instructed me in this matter. I learned the following: When you install the chips, you will have 768K installed on the CPU board. The computer will not recognize the last 128K. There is no harm in this. I don't know how you can put another 384K in the machine to use as a RAM disk. It may not be possible but I trust you don't care. We bought our 256K chips from I.C. Express. I would recommend them because they have served us well. Their prices are good too. Their address is: 15358 Valley Blvd City of Industry, CA 91746 (800) 892-8889 (out of CA) (800) 882-8181 (in CA) -- Tom Reingold; The Rockefeller University; 1230 York Av; NY 10021 PHONE: (212) 570-7709 [office]; (212) 304-2504 [home] ARPANET: reintom@rockefeller.arpa BITNET: REINTOM@ROCKVAX UUCP: {seismo|ihnp4|yale|harvard|philabs|phri}!cmcl2!rna!rocky2!reintom
anderson@uwmacc.UUCP (Jess Anderson) (01/15/87)
In article <314@rocky2.UUCP>, reintom@rocky2.UUCP (Tom Reingold) writes: > In article <1294@ncr-sd.UUCP>, lodman@ncr-sd.UUCP (Mike Lodman) writes: > > Would someone please respond via e-mail and tell me what ram chips > > are needed to upgrade a 256K Zenith 158 PC to the full 640K? > I believe you should get chips with a rating of > 120ns to ensure proper operation at 8 MHz. I have done this. I used 150ns chips (Toshiba, but any maker with a good rep and a favorable price should be OK). We have a PC maintenance guru where I work, and he said I would have no problems with 150 ns chips and need not invest in faster ones. I have been running the machine at 8 MHz since September with a full load of RAM. I have no problems of any kind (knock wood). There is a simple tool that compresses the pins slightly to make inserting the chips easier on your nerves. I didn't know about this tool at the time, but I had no problems with installation. If you end up wanting more RAM for RAMdisks, I've heard that not all add-ins work. For example, Tall Trees JRAM does not work. AST RAMpage does and Intel AboveBoard does. I have not yet tried either. On other upgrade matters, I have added an ST238 with Adaptec 2070a controller to get a 30 MB hard disk (works like a champ!). If you want an EGA, be aware that not all EGA boards work in a Z-158, but here I don't have any other reliable information. Doubtless someone else does. Good luck and have fun -- I sure am having fun with my machine! -- ==ARPA:==============anderson@unix.macc.wisc.edu===Jess Anderson====== | UUCP: {harvard,seismo,topaz, (avoid ihnp4!) 1210 W. Dayton | | akgua,allegra,usbvax}!uwvax!uwmacc!anderson Madison, WI 53706 | ==BITNET:======================anderson@wiscmacc===608/263-6988=======
pre1@sphinx.UChicago.UUCP (Grant A. Prellwitz) (01/20/87)
In article <2910@j.cc.purdue.edu> tim@j.cc.purdue.edu.UUCP (Timothy Lange) writes: >The Z-158 comes with one bank of 256K chips installed. There is room >for two more banks of chips. Yes, this does give a total of 768K, but >the ram decoder only sees the first 640K. >-- >Timothy Lange >Purdue University Computing Center Yes, this only addresses 640 Kb (DOS again) but there is a company called Computer Partners that supposedly sells a new RAM chip that will allow you to use a ramdrive to access that top 128Kb. They sell this for a Z-148 and a Z-158 (different chips). They apparently just started doing the 158. I know this is possible because it is done on all Kaypro PC's, but, since the chip hasn't come in for my Z-148 yet I cannot evaluate it. Their address/phone is: Computer Partners P.O. Box 1528 Suite 112 -- Waverly Building Koger Center Brentwood, TN 37027 (615) 373-2061. I got this info from BUSS and talking to them on the phone. I am in no way connected with them, not even as a user (yet). BTW, the chip for my 148 ran around $26. Grant Prellwitz !ihnp4!gargoyle!sphinx!pre1 76474,2121 CIS