Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!daver!bungi.com!news
From: george@wombat.bungi.COM (George Scolaro)
Newsgroups: comp.sys.nsc.32k
Subject: Re: Gatewayed mail message
Message-ID: <9104040818.AA12229@wombat.bungi.COM>
Date: 4 Apr 91 15:18:09 GMT
Sender: news@daver.bungi.com
Lines: 43
Approved: news@daver.bungi.com

[In the message entitled "Gatewayed mail message" on Apr  4, 14:01, stacey@guug.de writes:]
> 
> To:	pc532@daver.bungi.com
> Subject: PC532 RS232/V24 Serial Ports are DTE, (DCE is normal for a host).
> From:	stacey@guug.de (Julian Stacey)
> 

> 
> To quote the PC532 Functional Spec. Rev. 1.04 11/14/90 Page 4 Line 9:
> > Each serial channel connects to a 10 pin header which may be connected
> > (via a transition connector and cable) 1:1 to a DB9 connector 
> > (IBM PC/AT pin compatible).
> 

> 
> Why was the PC532 IDC configured as DTE ? possibilities include :
> - You can take ribbons straight from the PCB to modems. Remember multiple
>   modem connection inspired the original PC532 design.
> - Maybe the PC/AT configuration was taken as `standard' for a host computer, 
>   but it's not, it has a screen that can run a terminal emulator, has just
>   one or two ports normally, & is often connected via modem to a remote 
>   mainframe. Perhaps thats why IBM configured the PC/AT port as a DTE.

Of course it was wired to be compatible with PC/AT configurations. That way
all null modem connectors etc etc from 9 pin to 25 pin would work. It may
not be a real standard but I bet with the number of PC/AT's out there it
certainly is an industry standard... In addition any PC/AT add on like a
mouse etc will just plug in - most cheap peripherals are PC/AT compatible or
have the appropriate cables/connectors to be so.

If you hate PC/AT's or don't own any, then of course the PC532 configuration
wouldn't make sense. And yes, its planned use is for heaps of modems...
And yes, I took a lot of care to get the mapping from IDC to DB9 correct
(for AT compatibility).

Thanks for the DTE-DCE mapping info, I'm sure it will help lots of folks
that aren't conversant with RS232 hook ups.

best regards,

-- 
George Scolaro
george@wombat.bungi.com                [37 20 51 N / 122 03 07 W]