LC III amusement — #12

Post #12 by uniserver

Source Forum	68kMLA
Category	Troubleshooting
Post Date	Wed, 8 Apr 2015 - 20:04
Original URL	https://68kmla.org/bb/threads/lc-iii-amusement.1708/

Post

well that is interesting how the one long wire connects to the EGRET.

Coprocessors
Separate pages are in progress discussing technical features of each of the co-processors used on various Macs. These typically handle ADB, clock, and PRAM, plus power management features on portables and power on/off on some desktops.

68HC05-based Egret (LC, LC II, LC III, Classic II, IIsi, IIvx/IIvi),

341S0850 Egret (v1.01, earlier) PRAM, RTC, ADB; IIsi and LC

LCIII.jpg.510f8e7ab1f4eb6c81645c662a1ebf3c.jpg

u22, pin 11 looks like a ground from the schematic.

Screen Shot 2015-04-08 at 3.03.41 PM.png

so maybe it is a timing/clock issue? as to what that chip is there i guess one way to find out is to desolder it and see what is written on it.