home *** CD-ROM | disk | FTP | other *** search
- Path: sparky!uunet!haven.umd.edu!news.umbc.edu!nobody
- From: hybl@umbc.edu (Dr. Albert Hybl)
- Newsgroups: comp.sys.3b1
- Subject: Re: 3b1 Memory Chips
- Date: 25 Jan 1993 12:34:38 -0500
- Organization: University of Maryland, Baltimore County Campus
- Lines: 45
- Distribution: na
- Message-ID: <1k18beINNfa3@umbc4.umbc.edu>
- NNTP-Posting-Host: umbc4.umbc.edu
-
- Having finally located a cross-reference guide for RAMS, a useful
- list to have before starting a 3b1 memory upgrade project, I have
- extracted the equivalent designations used by the manufacturers to
- identify their 256x1 memory chips.
-
- I suggest that this list be added to the FAQ and the RAMupgrade
- documentation in the Ohio-State archive directory. Please
- review it for corrections and omissions. (The manufacture's names
- were not given in the cross-reference guide; consequently, I had to
- guess at some of the correlations. My little gray cells had
- difficulty relating MIT with Mitsubishi :-)
-
- If someone knows of a good collection of illustrations showing the
- correlations between a LOGO stamped on a chip and its manufacturer,
- I think a reference to the document in the FAQ would be helpful
- to a novice starting a memory upgrade project. [Better would be
- an electronic perusal program that shows an array of LOGOs and with
- a click of the mouse retrieves the name, address and (800) phone number
- for the manufacturer.] It is now economically advantageous to obtain
- chips from third parties (private sales, auctions or hamfests) where
- the manufacture's LOGO and identification stamped on the chip may
- be the only clues to what it was designed to do.
-
- ======================== A proposed addition to the 3b1.FAQ
- The following is a cross-reference list of 256 by 1-bit dynamic
- memory chips that are usable for 3b1 memory upgrades:
-
- AM90C256-xx AMD Advanced Micro Devices
- MB81256-xx FUJ Fujitsu
- HM50256-xx HIT Hitatchi
- HY53C256-xx - Hyundai
- P21256-xx - Intel
- M5M4256P-xx MIT Mitsubishi
- MCM6256-xx MOT Motorola
- UPD41256-xx NEC NEC Technologies
- MSM41256-xx OKI Okidata (?)
- KM41256-xx - Samsung
- TMS4256-xx TI Texas Instruments
- TMM4256C-xx TOSH Toshiba
-
- The digits in xx are speed designations--common values are:
- xx=10 for 100ns; xx=12 for 120ns and xx=15 for 150ns.
- =========================
-
- Albert (hybl@umbc4.umbc.edu)
-