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