The unverified schematic I arrived at from beeping out an original NODE
DATAPAC is now verified.
Based on that best guess original schematic I made a new schematic that
uses 1 256k sram instead of 8 32k sram, but otherwise replicates the
original circuit with the way the binary counters and bus latch works.
And the new device works!
https://github.com/bkw777/NODE_DATAPAC#minindp
This is kind of a pointless device today because in most cases a
Backpack is more useful and practical.
But here are a few distinguishing points:
* The driver software is only 1.4k on a 100, 1.2k on a 200, vs ts-dos
over 5k. Teeny is only 0.75k but lacks features (can't format a disk or
even list the directory)
* The DATAPAC or MiniNDP uses the system bus, leaving the serial port
available for other use.
--
bkw
