MNCAA is the D/A converter. It has 4 analog output channels with 12 bit resolution. The original module has knobs on the front panel to set the voltage range for each channel, and there is also a ‘trick’ in the 3rd channel of each module: the least significant 4 bits are also output in digital form; the idea was that if you would use MNCAA to control an analog plotter, then you could use those bits for instance to control the pen up/pen down signal.

The module is very simple in comparison to the other MINC modules. It doesn’t have a CSR, just 4 registers for the output channel values. Also it does not use interrupts.

MNCAA0  171060
MNCAA1  171070
MNCAA2  171100
MNCAA3  171110

There does not seem to be a limit to the number of MNCAA you can have in a system. MINC BASIC will use a maximum of 4, giving 16 D/A output channels.

Information sources
All information on MNCAA is derived from the schematics: MP00652_MNC11_Schematics_Jul78.pdf

Missing information

Implementation status
The implementation passes the VMND test program without errors, and appears to work flawlessly in MINC BASIC. The digital output on the 3rd channel is not currently implemented.