Found these inside a non-working 71B

[Dave Frederickson]

(03-17-2018 09:50 PM)MikeSD Wrote:  Oh wait! I just realized that this was wired as a Port, in my test unit. Ports use pin 10, 11 and 12 also. Pin 12 is tied high though. Any chance those may be causing it not to behave properly as a port device? Wonder if those were also needed when wired into the port zero string? And does the Math also need any of those?

According to the H/W IDS, Ch. 6.1, ROM Pin Descriptions, those other signals aren't needed. OD could be connected, but it's only necessary if you want the Service Module to disable the ROM.

Dave