Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!sdd.hp.com!hp-pcd!hplsla!tomb
From: tomb@hplsla.HP.COM (Tom Bruhns)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Can I replace a MC74F139 IC with a 74LS139 IC??
Message-ID: <11260003@hplsla.HP.COM>
Date: 12 Mar 91 17:10:33 GMT
References: <1991Mar10.185521.14238@engin.umich.edu>
Organization: HP Lake Stevens, WA
Lines: 11

Ive gotton ahold of a number of 74LS139 chips, and I'm going to replace
the MC74F139 with it. The difference being LS vs F.  I think LS means
low power Shottsky, but what does F mean, and can I interchange the
chips? Does this make them incompatable?
----------------------

Not incompatible, per se, but you should know that the speeds are much
different; the F series is FAST:  Fairchild Advanced Schottky TTL or
something like that.  LS is low power Schottky, and about half as fast,
depending on the particular type.  (didn't bother looking up 139's for
you.)