This page describes the IBM SMS card "TFC", and is part of the SMS card database.

Function of the card:
SDTRL-compensated low power inverter
SDTRL -inverter, power- pnp
SDTRL-Inverter, Power-PNP [SDTRL - Compensated Low Power Inverter]

Quad Inverter w/ speedup capacitors

Saturated Drift Transistor Resistor Logic (SDTRL) is a form of resistor-transistor logic using faster drift-field transistors.

Part number: 370646

PCB number: 484425

Used in: IBM 1311 Disk, IBM 1620

Cap code: None (details)

Symbol: I, IP

Pinout:

A O4
B I3
C O3R
D O2
E O3C
F I4
G
H
J GND
K I1
L O1C
M -12V
N +12VM
P I2
Q
R O1R
References: IBM 1620 Instructional System Diagrams, p496
IBM 1311 ILD, p138
Coslet data

The information on these pages comes from a variety of sources, especially old IBM documents on bitsavers.org, as well as information from the IBM 1401 restoration team, especially Tim Coslet's SMS data and Jim Hunt's data. Much of this information was obtained through OCR, so don't expect complete accuracy. These pages are not associated with IBM in any way.