From wolff@liberator.et.tudelft.nl  Ukn Jul  2 10:04:32 1993
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Date: Fri, 2 Jul 93 16:02:22 +0200
From: wolff@liberator.et.tudelft.nl (Rogier Wolff)
Message-Id: <9307021402.AA07551@liberator.et.tudelft.nl>
To: riscy@pyramid.com
Subject: "what we really need".
Status: RO
X-Status: 




> * Serial I/O. For starting the Linux port, we will need
>   two ports; one for a dumb ascii terminal, one for downloading
>   code.

I am not objecting to 2 serial ports in general, but there is no
reason at all to do code downloads on a different serial line.

The boot rom should boot the processor and go into an endless loop
providing a prompt, and reading commands. The three essential
commands are "peek %d", "poke %d %d" and "go %d". 

Downloading code goes through the poke command.

>   Two ports are still sufficient for a workstation:
>   One for the mouse, the other one for the modem.
>   A third port is an *option*. It could be used for a printer
>   in case we don't have a parallel port.

I think that you are right here: two ports is not a bad investment 
after all. The first goes to a mouse, the second is quickly used, and
more are optional. However if a 4 port chip is available, I wouldn't
object .....

					Roger.



 
