PDP-11/70 debugging advice

Fritz Mueller fritzm at fritzm.org
Thu Feb 4 16:42:19 CST 2021

> On Feb 4, 2021, at 1:51 PM, Josh Dersch <derschjo at gmail.com> wrote:
> [RC maintenance clock] Yeah, you'd think... but it doesn't work :).  I mentioned earlier in this thread that it's stuck in single-step mode.  From the schematics it looks like the crystal clock needs to be running to clock some of the flip flops used in the "Source Synchronizer" to select the proper clock source.  My guess is that since the clock isn't running, the flip flops are left in a weird state.

Oh, interesting!  Noted for future reference.  The TIG is not exactly straightforward...

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