Histo12

Summary

HISTO12 is an interspike interval plotting routine designed for the PDP-12A computer, intended for use in electrophysiological research. The program utilizes an adjustable threshold to filter out baseline noise and ignores spikes shorter than 500 microseconds or longer than 2.1 milliseconds.

Key features and functionalities include:

• Data Collection: Users can set a preset limit for the number of spikes counted (up to 4095). Sampling is controlled via an analog input and can be terminated by the user or upon reaching the preset limit.
• Output: The program provides sampling diagnostics, including the total count of spikes, average input frequency, total sampling time, and the number of spikes excluded from the display (intervals greater than 1.6 seconds).
• Visualization: It generates data displays in either scattergram or histogram mode. These can be expanded horizontally to define intervals ranging from 0.0–0.2 seconds up to 0.0–1.6 seconds. Vertical scaling can be adjusted through addition, subtraction, multiplication, or division commands.
• Operational Controls: The software includes features to facilitate documentation, such as a histogram display option using sense switches, a 15-second development timer for Polaroid photography, and various teletype commands to scale, multiply, or divide the display data.

The document includes the complete source code, a core map, and a symbol table for reference.