22 Dec
2008
22 Dec
'08
12:11 a.m.
On Sunday (12/21/2008 at 06:53PM +0000), Tony Duell wrote:
Perhaps a prototype Appletalk interface? The 26LS30 xmit enable is
controlled by the RTS output of the ACIA so it was probably a half-duplex
link... ala RS485, which I believe is what Appletalk was.
The 6551 won't do sync or any of the fancy header detection that the
Z8530 did... which I think is what ultimately became the Appletalk
interface in the Mac.
Chris
--
Chris Elmquist
mailto:chrise at pobox.com
http://flickr.com/photos/spaceageboy/3117272956/sizes/o/
Would this be the interface between the Lisa and the Mac as related here:
Well, it's clearly an ansynchronous serial interface (the 6551 chip) at
RS422-ish levels, so that side would talk to a Mac serial port. WHat the
host bus is, I can't say, but it might well be Lisa.