[parisc-linux] Parallel port hardware

[Sandy Harris]

Sandy Harris wrote:
|Can anyone point me to info on the electrical properties of the parallel ports
|on 712 or 715 machines?
|
|I'm thinking that 8 715s might make an interesting parallel engine, but the cable device
|only works if the parallel port's control lines are implemented as open collector TTL.
|Where can I discover whether they are?

Early 715s (/33, /50, /75) use a WDC 16C522 (or is it 552?) for the 2
serial and one parallel ports.  Perhaps you can find info on thier
web site.

Later 715s (/64, /80, /100) and all 712s use Lasi.  From the chip ERS
(not published, it's mostly electrical stuff) Data strobe, autofeed,
parinit, and select

The ones that connect to pins 1, 14, 16, and 17 are open collector.

	-Bill Katz