3406 and 340D shares some memory locations without being overly careful about synchronizing access: https://github.com/PDP-10/its/issues/1600 In particular they will both use halfword instructions to write ones or zeroes to the left half of the words in the table FLAGS. E.g. HRROS or HRRZS.
I have noticed that sometimes this will result in words being left all cleared.
larsbrinkhoff
commented
4 years ago
3406 and 340D shares some memory locations without being overly careful about synchronizing access: https://github.com/PDP-10/its/issues/1600 In particular they will both use halfword instructions to write ones or zeroes to the left half of the words in the table FLAGS. E.g. HRROS or HRRZS.
I have noticed that sometimes this will result in words being left all cleared.