DEC PDP-8/e H212 core mat repair

------ Original Message ------ From: "Tom Hunter via cctalk" <cctalk at classiccmp.org> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Monday, 19 Jul, 2021 At 06:33 Subject: DEC PDP-8/e H212 core mat repair I am curious if anyone has attempted to repair (replace) a broken wire in a PDP-8/e H212 (MM8EJ) core mat (8 k word). The cores are not visible without a microscope. I cannot imagine how these were even manufactured and wonder if DEC service centers repaired core mat faults or if faulty boards were simply discarded. CDC 6600 cores were huge in comparison and I would not hesitate to replace a broken core wire on those. Best regards Tom Hunter These patents might be enlightening. I'm sure there's others, but these are some i've found on a quick search. https://patents.google.com/patent/US4161037A <https://patents.google.com/patent/US4161037A> https://patents.google.com/patent/US3668664 <https://patents.google.com/patent/US3668664> Josh