M/N
Storage
@
Each flag can be enabled (interrogated), or all flags can be enabled.
U30
and U32 provide the
logic, and
U20
stores the state of the enabled flags.
Address Decoder
@
U7, UlO, and U33 decode the address lines, enabling the appropriate ICs to gate or store data
for the Data Bus.
Attenuator
Correction
Rom
@
U8 is a PROM (programmable read-only memory) that contains the attenuation errors
(calibration data) of the RF attenuator.
Control
Lines
@
U9
controls certain mainframe functions, such as turning off the internal reference oscillator
(IISTD).
Options
@
U21
gates the Options jumpers onto the Data Bus.
2 A12