155-0023-00
The Tektronix 155-0026-00 is a custom chip for the 7000 series readout system. It is an analog read-only memory used as a Character Generator for 10 numerals (0 1 2 3 4 5 6 7 8 9), packaged in a 16-pin plastic DIP.
The numeral 0 also doubles for the letter O that is not included in the letter groups.
The chip was designed by Barrie Gilbert.