IBM Memory Writer
History and Useful Information
The IBM Memory Typewriter rolled out in January of 1975. Other than being a typewriter, it has an integrated memory bank that can store up to 100 documents a "few paragraph length". It is one of the first implementations of IBM's racetrack memory. This machine is very similar to an IBM Selectric typewriter in operation, other than the memory functions, but it does not work exactly like an IBM Selectric. This machine takes the digital output of the keyboard and turns it into an analog output using solenoids installed on the many functions of the Selectric instead of using mechanical linkages. This allows the memory to log keystrokes when it's being used in the memory mode, and it allows the memory to quickly execute operations by manipulating the machine through the solenoids.
Like the IBM Selectric, this machine falls victim to being very sensitive to dust. Any dust inside the machine will cause the grease to coagulate, rendering the typewriter seized. These, like Selectrics, also tend to have broken return cable pulleys and old crusty belts. Unlike the Selectric, these typewriters are equipped with a pair of fuses (one 24v 2A fuse and one 24V 4A fuse) which may be blown and in need of replacement.