SCSI or ethernet via parallel port ?

Ron Wilson rlw at ttardis.UUCP
Sat Feb 2 15:13:19 AEST 1991

In article <38458 at>, thad at (Thad P Floryan) writes:
>merce at iguana.uucp (Jim Mercer) in <1991Jan25.035120.11117 at iguana.uucp> writes:
>	there exist on the market a number of "thingy"'s that attach to the
>	parallel port.
>	[...]
>	but there are newer gizmos which can, with drivers under MS-DOS, adapt
>	the port into a SCSI controller or an ethernet NIC.
>	[...]
>	on the unix-pc/CT miniframe, you can write loadable device drivers.
>	could a driver be implemented to use one of these devices?
>Nope.  The 3B1/UNIXPC's parallel port is NOT a programmable I/O device with
>data-direction registers; it is a printer port, period.

While I can't speak for these parallel port SCSI and ethernet adaptors, I do
know that PC products like Fast-Lynx (aka Fast-Wire), Brooklin Bridge, Lap
Link and others use the port data pins ONLY as outputs and use the control
signal inputs for data input - thus only transfering 4 data bits at a time
with OUT reconfiguring the parallel port.

In theory, the same trick could be used with the Unix-PC parallel port.

About MS-DOS: "... an OS originally designed for a microprocessor that modern
                kitchen appliances would sneer at...."
                   - Dave Trowbridge, _Computer Technology Review_, Aug 90

rlw at ttardis	    uunet!!cfctech!ttardis!rlw

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