Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!nrl-cmf!cmcl2!phri!dasys1!schuster
From: schuster@dasys1.UUCP (Michael Schuster)
Newsgroups: comp.sys.ibm.pc
Subject: Re: What kind of ROM? (WAS: IBM ROM BIOS upgrade kit
Summary: Probably 68764
Keywords: ibm pc rom bios upgrade kit
Message-ID: <6036@dasys1.UUCP>
Date: 18 Aug 88 17:25:21 GMT
References: <927@orion.cf.uci.edu> <5962@dasys1.UUCP> <11872@steinmetz.ge.com>
Reply-To: schuster@dasys1.UUCP (Michael Schuster)
Distribution: na
Organization: The Big Electric Cat; New York, N.Y. USA
Lines: 23

In article <11872@steinmetz.ge.com> davidsen@crdos1.UUCP (bill davidsen) writes:
>In article <5962@dasys1.UUCP> schuster@dasys1.UUCP (Michael Schuster) writes:
>
>| Related subject: does anyone know what kind of ROM was used in the
>| original IBM PC (not XT) of which this is a replacement? By this
>
>  First, my old tech ref says the ROM is 8k x 8, so I think that's 2764.
>The part I'm not sure about is if there are two address pins flipped on
>the ROM, such that it can be read in order only in a modified socket,
>although it could be duplicated in a standard PROM burner.


I've been told the original EPROM had a Motorola pinout, and that a
68764 or 68766 would work. These are 24-pin devices (like IBM's). I
don't think a 2764 would work in any configuration (read or write),
as it's a 28 pin device. 

Both devices are still listed by the big mail-order houses (Jameco
and the like). Anyone happen to have a pinout?
 
-- 
l\  /l'   _  Mike Schuster          {sun!hoptoad,cmcl2!phri}!dasys1!schuster
l \/ lll/(_  Big Electric Cat       schuster@dasys1.UUCP
l    lll\(_  New York, NY USA       DELPHI,GEnie:MSCHUSTER  CIS:70346,1745