Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!purdue!decwrl!hplabs!hpda!hpcupt1!hpcuhb!hpindda!mintz
From: mintz@hpindda.HP.COM (Ken Mintz)
Newsgroups: comp.sys.ibm.pc
Subject: RFC: old PC, AT compatibility
Message-ID: <4330064@hpindda.HP.COM>
Date: 28 Apr 88 17:43:53 GMT
Organization: HP Technical Networks, Cupertino, Calif.
Lines: 31

I'm replacing my 5-year-old IBM PC (8088) with an AT.  I've been assuming
that there was a very high degree of s/w compatibility:  that most things
written for the PC would run on the AT.

Is that a reasonable assumption?  I know there will be exceptions, esp.
for any games that might be sensitive to the cpu speed.  But can I expect
compatibility as a rule for, say, 90% of the s/w?  I've seen s/w packages
that specifically state "works on PC, AT,...".  If it says only "for IBM PC",
should I presume that it does NOT work on the AT?

If compatibility is indeed the "rule", can anyone suggest some things to
look for which betray INcompatibilities?  My thinking is that perhaps the
AT is DOS-call compatible; but programs that go directly to ports or to
memory locations will fail.  True?

I have 2 programs that I was surprised could not run on the AT.  Can
someone explain why (or provide an intelligent guess)?

   (1) BASICA (very old) caused the AT to hang, altho ctl-atl-del worked.
       BTW, "BASICA" is the same as "GW-BASIC", right?

   (2) Multiplan (very old) also caused the AT to hang, altho ctl-atl-del
       again worked.  MP is copy-protected on a 360K floppy that I tried
       to run from both the 1.2M and 360K drives.

Any insights and pointers to articles discussing PC-AT compatibility would
be appreciated.

Thanks in advance.

Ken Mintz