Hi, Reference: > From: David Brodbeck <g...@gull.us> > Date: Wed, 20 Oct 2010 14:58:40 -0700 > Message-id: <aanlkti=zo1ojzcqs4xyezvmkonmt6uv_vmqki0hik...@mail.gmail.com>
David Brodbeck wrote: > On Wed, Oct 20, 2010 at 1:10 PM, Arthur Chance <free...@qeng-ho.org> wrote: > > On 10/20/10 20:46, Bob Hall wrote: > > Getting back to reality, although I never did it (fortunately), a friend of > > mine who was about a decade older than me (I'm mid/late 50s) had the > > experience of programming microcode on a machine by inserting brass slugs > > for 0s and ferrite slugs for 1s on a pin board. Anyone got any idea what > > that was? He was (UK) military so maybe it wasn't a generally known box. > > Don't know about that one, but some early desktop calculators (and I > think some early computerized phone switching systems) used etched PC > boards as ROM. The HP 9100 had 32K of ROM on a 16-layer PC board > using this method. Some Hasler (a Swiss co.) leased telegraph message switching systemss M150 had that too. I designed some cards with DIL switches, After 1975 I think. Cheers, Julian -- Julian Stacey: BSD Unix Linux C Sys Eng Consultants Munich http://berklix.com Mail plain text; Not HTML, quoted-printable & base 64 spam formats. Avoid top posting, it cripples itemised cumulative responses. _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"