MITS 1440 Electronic Calculator

Here is some information I have assembled which may be useful:

MITS 1440 Manual Desktop Calculator (4.2 MB)

MITS 1440 MOS Chipset Technical Information (my document) (110 KB)

1440 MOS Chipset schematic with more signals labeled - Left (1.6 MB)

1440 MOS Chipset schematic with more signals labeled - Right (1.6 MB)

1440 Display Alternating circuit schematic marked up to match my unit's PC board (132 KB)

(The MITS 1440 used Electronic Arrays chips FDY 360B-7006, FDY 320B-7002, FDY 120B-5013, FDY 110B-5001, FDY 310B-7014 and FDY 150B-5005. If you have any technical information on these chips, please contact me. (I now have a working PIC-based emulation of the FDY 360B-7006 ROM chip.) The MITS 816 and ICM 816 calculators used similar chips, so my Technical Information document should be helpful for working on those as well.)