Found these inside a non-working 71B

[Dave Frederickson]

(03-15-2018 05:09 PM)MikeSD Wrote:  If I said that, I must have been tired. I think the only place I used 10 is that the U9-9 is routed to the Math ROM-8 and also to pin 10 on U9, for some reason.

I noticed there is a Forth Assembler part number for "with and without" a debugger. My part number is for the with debugger. Wonder how I verify that? Is the debugger a hardware item, or another ROM, or part of the Assembler?

Mike,

You didn't call that part U10, I did. Schematically speaking, it needs a reference designator. U10 is just the next number in the series.

Yes, the F/A module was later marketed with a debugger, but it's software. The physical ROM is the same.

The IDS, however, mentions a hardware Debugger ROM several times. I suspect that U10 is where it was to be installed. Also of interest, the Service ROM contains a debugger very similar to the 82478A Debugger, but it's undocumented(!)

Dave