This is an advertisement for the MITS 7440 Scientific Desktop Electronic
calculator. This was MITS' last desktop electronic calculator, with the company
opting instead to focus on the handheld calculator marketplace, offering
both kits and fully-assembled handheld calculators, as well as also
serving as an OEM manufacturer, selling fully-assembled, un-badged handheld
calculators to customers for them to brand and sell as their own.
The 7440 could be paired with an updated version of MITS' Programmer, which
allowed the 7440 to be programmed to carry out rather complex programmed
operations. The version of the Programmer available for the 7440
looked identical to the earlier Programmer that could be connected to
MITS' earlier desktop calculators, including the
816, 1440 and 908DM calculators.
The Programmer functioned by electronically
activating the keys on the attached calculator by using an array of transistors
in the programmer. When a key-code was encountered in a program,
the transistor corresponding to the key on the calculator would be turned
on briefly, which would make the calculator "believe" that the actual key
had been pressed, causing the operation to be performed as if a human had
pressed the key. The reason a different version of the Programmer was required
specifically for the 7440 was that it had many more keys on its keyboard
than the earlier calculators, and the size of the transistor array (along
with the requisite selection circuitry) in the Programmer had to be increased.
This made the Programmer for the 7440 unique. The 7440 calculator is connected
to the Programmer by a more complex multi-pin connector than the
25-pin DB-25 connector used to connect the earlier Programmer to the
816, 1440, or 908DM calculators.
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