Commodore PET User Manual page 181

ROLL
OVfR!
Without this buffer. rapidly incoming keystrokes wou Id be lost before printing -
and rollover would be impossible.
The following flowchart shows how rollover works in greater detail. The PET
must store incoming keystroke #2 in the buffer until keystroke #1 is printed.
Once keystroke #1 is printed. keystroke #2 is taken from the buffer and printed.
Press
KeY1
Print
character
End of
keystroke
processing
Store
character =lf2
in buffer
Print
2nd character
End of
keystroke
processing
Ail
VOU
need to remember about roi lover is that it is a beneficial feature of
the PET keyboard that allows vou to type in data faster than vou could if roi lover
were not present.
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