This might be an odd question on an old processor, but I have written an emulation of a Heathkit ET-3400A microcomputer trainer in Java. I was adding the ability to trigger interrupts, and the Motorola 6800 datasheet indicates the I flag (interrupt mask) is set at reset. The 6800 programmer's reference, however, has a passage that indicates it is cleared at reset. Anybody know which one it is?
1 Answers
Because this is not an MC6800 specific question, but it is about all documents from the 1990s and earlier, I will answer here and not on retrocomputing.stackexchange.com:
... if the interrupt mask bit is in the reset state ...
Until the 1990s, the word "reset" typically meant what we would call "cleared" today.
In some contexts (for example "RS-Flip-Flops") the word "reset" still means "cleared" (and not: "initial state") today!
So the text in the Programmer's Manual actually means:
... if the interrupt mask bit is in the cleared state ...
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