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Path: utzoo!linus!philabs!seismo!hao!hplabs!hp-pcd!orstcs!nathan
From: nathan@orstcs.UUCP
Newsgroups: net.micro
Subject: Re: Orphaned Response - (nf)
Message-ID: <1797@hp-pcd.UUCP>
Date: Fri, 9-Sep-83 03:52:24 EDT
Article-I.D.: hp-pcd.1797
Posted: Fri Sep  9 03:52:24 1983
Date-Received: Sat, 10-Sep-83 22:37:05 EDT
Sender: notes_gateway@hp-pcd.UUCP
Organization: Oregon State University, Corvallis, OR
Lines: 31

#R:sri-arpa:-446200:orstcs:24000005:37777777600:1243
orstcs!nathan    Sep  7 01:12:00 1983

*** warning *** economic self-interest

re: apple serial card w/ interrupt support

1. Might I recommend the PSIO Dual-Function card from Videx, Inc. It has
   software baud generation, on-board non-volatile setup memory, a built-in
   parallel port to connect to a printer, firmware for dumb terminal and
   graphics dumps (the latter "coming soon", before end-of-month) and
   it "phantom slots" itself so that software that insists the two ports
   be on different cards doesn't get upset.  For independent recommendation,
   note that the guys who wrote Ascii Express use it now.

2. Interrupts on the Apple Bus: be warned, all is not rosy with apple
   interrupts.  The 6551 chip used on the PSIO card (and others; it seems
   to be the standard auto-baud chip on apples) has a quaint "feature" in
   which: if the receiver is turned on, there is *no* way to disable the
   interrupt that occurs when the modem status lines toggle.  This is very
   upsetting to programs like Visicalc, which tend to crash when they get a
   spurious interrupt.  There is a switch on most cards to break the interrupt
   line, but it's a hassle to switch it every time you want to use your
   terminal program.

   anyhow, *** flame off ***

	nathan