Did some reverse engineering of the Caglec 452 Baud Rate Generator (M452
replacement) for Robert K. Managed to figure out what the jumpers and switches
do.
12/20/03
to 12/23/03 Worked with Tim on the RS-232 interface for his 8i.
12/11/03
Fiddled some more with the idea of NVRAM based PDP-8i memory. Managed to
clear up most of the mystery about how the memory bus works (but not the
pin-out).
12/10/03
Experimented with the idea of making replacement memory for the PDP-8i
based on NVRAM. Got a little mired down trying to understand how the 8i memory
works. Also exposed a discrepancy between the memory bus description in the 8i
schematics and in the MC8i schematic.
12/07/03
"Finished" working on the paddle connector design with Guy S., at least
until someone wants to order boards. Thanks, Guy!
12/06/03
Continued to work issues in the paddle connector design with Guy S.
12/05/03
Started working on design of paddle connectors for Posibus/Negibus
connectors.
12/04/03
Put together a parts order for a reader-run mod. Maybe I should make that a
project, as there seem to be a number of people which have TTYs that need one.
12/03/03
Got the W076x board artwork accepted. Parts came from JameCo, so I built
12 parts kits. Ran out of .1uf capacitors, so I'll have to order some more.
12/02/03
Ordered the W076x boards.
12/01/03
Ordered the M452X boards and the parts from JameCo. Had to rework the
silkscreen for the board shop. Got the oscillators from DigiKey.
Also got the current loop connectors from DataTerm.
Got the resistance info on the reader-run relay and modified the reader-run
circuit to match, though it is clear there is weirdness in the reader-run mod
relative to the drawings.