The RTI-1221 analog I/O board from Analog Devices was designed specifically for Pro-Log 8080 and 6800 based microprocessor systems (pre STD Bus). The RTI-1220 is a 16-channel data acquisition board while this RTI-1221 is a 4-channel analog output. These were introduced in 1977 with the RTI-1221 priced at $235
Analog Devices also made an RTI-1201 for Intel’s SBC-80 multibus platform.