Re: x86 architecture concepts

From: Paul Carpenter (paul$_at_pcserv.demon.co.uk)
Date: 02/26/05 

Date: Sat, 26 Feb 2005 22:33:11 +0000 (GMT)

On Saturday, in article <8cSdnUye0uqibL3fRVn-hg@omsoft.com>
     jstewart@jkmicro.com "Jim Stewart" wrote:
>Robert Kaiser wrote:
>> In article <vUYTd.945$C47.661@newssvr14.news.prodigy.com>,
>> Kelly Hall <khall@acm.org> writes:
>>>Robert Kaiser wrote:
>>>
>>>>So, apparently, technical elegance does sometimes pay, *especially*
>>>>in the embedded market.
>>>
...
>>> Forth.
>>
>>
>> What with Forth wrong is? Strange UPN you may find, but else?
>>
>>
>>> RS-232.
>>
>>
>> And whats wrong with this?
>>
>It's hard to name anything that's right
>with it. Swinging several volts from
>a positive rail to a negative rail to
>transmit at a low symbol rate for a few
>meters...

Having seen the standard being used to transmit down a couple
of kilometres, obviously I am wrong.

Unless of course you are referring to the MIS-interpreted
12-15m distance quote about noise.

>The 'standard' involved a DB-25 connector
>with about a dozen signals, which everyone
>implemented differently...

RS232 did NOT specify the conncetor until RS232-C onwards.
The DB-25 connector was a PTT standard (CCITT later ITU-T)
specification for modems, hence the DTE/DCE specifications.
Also the synchronous/asynchronous for 300baud to leased line
specifications.

RS232 did not specify things like DTR/DSR or CD/RI that was the
modem specifications hence NULL modem cables.

>How many manhours has been wasted dicking
>around with serial cables?

Mainly by those who did not understand the standard and grabbed
any old cable. 

-- 
Paul Carpenter          | paul@pcserviceselectronics.co.uk
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