Re: Ortonview PCB
Nice work Mark, I will start to build this mod onto my board. It certainly looks as though it is shifting the relative timing of NWDS and the address bus change to good effect.
With regard to AM9111s, it is not so unusual to get a bad one, they are getting on a bit now. I don't imagine the sellers have the means to test each and every type of chip which comes their way. If they buy in a few tubes of NOS ICs, it is not unreasonable to hope that they will be OK if they look as though they haven't ever been used.
One of four of the ones I ordered from the German source pointed to by circuitryboy a while back was also dud, but promptly replaced with two, not just one, by that source. Both replacements were good, I offered to send one back, the seller declined, so I would not hesitate to use them again- unfortunately, they didn't have any more stock of AM9111 when I last checked.
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