MITS 1440 Calculator

B Degnan billdeg at
Thu Feb 19 20:35:42 CST 2009

Does anyone have a MITS 1440 Calculator?  I am looking for someone who 
either has a non-working  unit, or one that needs some sort of 
attention, or someone who would be trusting  enough to loan me and a 
friend their working unit to carefully swap the ROM chips and see which 
one is bad.  I think the risk of damaging a good chip is low, but 
paranoid attention will be made to avoid accidents.  I have been told 
that the input chip is OK, and the output  chip is OK.  The control chip 
seems OK.  Most likely the program ROM chip is bad, but it could 
possibly  be the registers or ALU.  More likely the ALU than the 
registers chip.If anyone is interested in this project, feel free to 
drop me a line.  See July 1973 Radio Electronics for more info.
Bill D

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