PDP11 PeripheralsHbk 1972 - Trailing-Edge

3.3.2 DRll-A Implementation
A convenient method of implementing an interrupt serviced interface is to use an
M786 General Interface Module to make a DRll-A 16-Bit General Interface. Figure
3-6, a layout of the modules mounted in a DDl1-A System Unit, shows the
savings in space and interconnections_ The DDll-A System Unit is prewired to accept
four DEC small peripheral interfaces; e_g., DR11-A_ A discussion of the DR11-
A, including specifications, is presented in Paragraph 2.2_6.
Figure 3-7 is similar to Figure 3-5 because the DRll-A logic is used in the same
manner and with the same programs as any other logic used to implement an interrupt
serviced interface. The M786 Module portion of the DR11-A provides cable
connectors; therefore, no additional wiring or connectors are required.
Connections between the ADC and the M786 Module are made as follows:
CONNECTOR
1
2
DRll-A
OUT (06:00)
NEW DATA READY
IN (09:00)
REQUEST A
253
ADC
Multiplexer inputs
Start conversion
Digital outputs
Conversion complete