Xref: utzoo comp.std.misc:169 comp.windows.misc:1165 comp.misc:6605 comp.periphs:1943
Path: utzoo!utgpu!attcan!uunet!iscuva!jimc
From: jimc@iscuva.ISCS.COM (Jim Cathey)
Newsgroups: comp.std.misc,comp.windows.misc,comp.misc,comp.periphs
Subject: Re: User Interface Standards -- *Keyboards!*
Message-ID: <2577@iscuva.ISCS.COM>
Date: 20 Jul 89 16:55:47 GMT
References: <115518@sun.Eng.Sun.COM> <29607@ism780c.isc.com> <1989Jul15.034605.28654@cs.rochester.edu> <29738@ism780c.isc.com> <20581@cup.portal.com>
Followup-To: comp.std.misc
Organization: ISC Systems Corporation, Spokane WA
Lines: 37

In article <20581@cup.portal.com> spage@cup.portal.com (S spage Page) writes:
>The de facto standard is the IBM 101-key keyboard on the PC AT.  You can buy
>...
>As to whether it's a GOOD standard,...  It duplicates the cursor control and
>...
>Another advantage of the PC AT hardware standard is the number of plug-
>compatible special designs available for it.  I have bad arthritis and
>...

And a monstrously big _disadvantage_ of the PC keyboard series is its TTL
signal interface.  Probably the most noise-sensitive interface they could
have chosen.  You are extremely limited in how far you can extend the cable
before you start getting unreliable keystrokes, especially if you package
video into the same cable.  Plus it expects 5V regulated power, another
no-no for longer cables.

Our keyboards use RS-422 and we routinely get 3000 feet of cable on these
signals with no problems.  It's also a low-speed LAN in that we get 8 
keyboards and 8 printers all on the same wire, with only one serial 
controller.  Very handy for installing low-cost multi-user stations.

Unfortunately us designers are besieged by legions of marketing types dancing
in a circle around us and chanting "Off the SHELF, Industry STANDard..." 
They expect the same sort of thing that we do with our custom keyboards to
be done with AT keyboards, only "cheaper".  After all, a keyboard's a 
keyboard, right?  

Grumble.

+----------------+
! II      CCCCCC !  Jim Cathey
! II  SSSSCC     !  ISC-Bunker Ramo
! II      CC     !  TAF-C8;  Spokane, WA  99220
! IISSSS  CC     !  UUCP: uunet!iscuva!jimc (jimc@iscuva.iscs.com)
! II      CCCCCC !  (509) 927-5757
+----------------+
			"With excitement like this, who is needing enemas?"