7M13

The Tektronix 7M13 is a "Readout Unit" that allows the user to enter text into the scope's readout system for that module slot. It is intended to include identifying text and picture numbers for photographic documentation.

Tektronix 7M13
Readout Unit 7M13 front panel Compatible with 7000-series scopes Produced from 1974 to 1985 Manuals Tektronix 7M13 Manual (OCR) (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

A built-in camera counter displays a pre-settable count in the second (lower) readout channel, which can be advanced manually by push-button or automatically by the camera shutter. The only editing function provided is to overwrite the character just entered (by holding the MODIFY button). To correct other errors, one needs to erase the display field.

Key Specifications

Character positions	2 fields (top, bottom) of 10 characters each
Camera counter	0-99, lower field only; ground contact closure input

Internals and Repair Issues

The 7M13 is relatively simple and robust electrically, consisting mostly of 74xx TTL logic. However, there can be electromechanical problems due to the number of switches. For example, a 7M13 may appear unresponsive if the "(P)RESET" button for the camera counter is not fully released.

The 7M13 uses four 7489 TTL 16×4 RAMs to store the characters entered, and four 155-0038-01 Tek-made D/A converter chips to drive the analog row/column readout lines. One RAM and D/A each are assigned to row and column readout signals in each channel, and are addressed by a counter synchronized to the readout time slot pulses. In other words, characters are not stored as ASCII bytes, but as row/column pairs matching the readout system's character set. The keyboard is arranged in a matching matrix of double-contact (DPST) keys that generate the row/column coordinates through 74147 priority encoders.