lupin@bogart.WEITEK.COM (Ed Lupin) (10/14/89)
Can someone please tell me what the current requirements are to drive the Appletalk network, or better yet, a recommended circuit that has worked well? We plan to parallel two ICL7660's to get sufficient -5V current, and use 26LS30's and 26LS32's, but is that the most efficient method? Our PC board space is limited. Also, Inside Appletalk suggests that Appletalk may be driven unipolarly, with +5V and 0V only. I have my doubts. Comments? Thank you. Ed
stevel@eleazar.dartmouth.edu (Steve Ligett) (10/24/89)
In article <829@bogart.WEITEK.COM> lupin@bogart.WEITEK.COM (Ed Lupin) writes: ... >Also, Inside Appletalk suggests that Appletalk may be driven unipolarly, >with +5V and 0V only. I have my doubts. Comments? If you're putting in filters like Apple has in the Macs, drive it with +/- 5 volts, otherwise you can just use +5. The filters throw away about half the signal. We're using 75176's as drivers, and there's a bunch of others to look at rather than the 26ls30. All of this is from memory - our stuff was designed in '84. -- Steve Ligett steve.ligett@dartmouth.edu or (decvax harvard linus true)!dartvax!steve.ligett