A friend gave me this old vintage AIM65 from Rockwell - (1975)
Well... No 24 Volt yet... "PRINTER DOWN"
Wondering about the limit of installed RAM, only 1K on board, I looked closer to the motherboard and found ...
this BLACK devel...
Had som 2114 RAM, so now there is 3 K RAM onboard.
What is this blok of things ???
This is a watch-krystal, so it must be a "System Watch Interface"
Interfaced to the expanding Bus here...
White, Yellow, Gray and Green = D0 - D3
RED = SYS R/W
LILLA = CS9
BROWN = + 5 Volt
BLACK = GND (0 Volt)
NO other connection under the PCB !!!
I can remowe the connector from the bus, without any problem, NOTHING happends...
BUT BUT BUT... Not so clever made...
It hangs up the lower part of RAM-memory, so I remowed it from the AIM65.