OK, I managed to scan my old readout exerciser schematic, posted here:
/g/TekScopes/album?id=266548Now I'm remembering some details. I had to do some tricks to skip certain parts of the code table and functions, so only the character set would show. It does not test any of the other RO functions. For a universal type interface/test setup, you'd want to have all of the code table available, using the full current ranges. Another reason to use IC DACs, is that you can include the provision for limit testing. Rather than just the nominal current steps from a 4-bit DAC, with say 8 bits, you could tweak the values around to check where the readout decides the values.
Ed
