Dataman S4 - Manual (Page 50)

DATAMAN S4 MANUAL
50 SUM KEY (green)
SUM KEY (green)
The green SUM key operates on the PROM in
the ZIF socket. It performs a checksum on all
the locations of a ROM in the ZIF socket. The
CHECKSUM ROM function allows the user to
take the checksum of a ROM device without
first loading it into RAM, thus avoiding over-
writing USER MEMORY. The PROM TYPE as
specified in CONFIG is displayed. The
CHECKSUM is presented the answer as a
eight digit hex number. A CHECKSUM
provides a "signature" for identifying and
labeling programmed PROMS. Master PROMS
should be labeled with their CHECKSUM to
ensure that they have not been over-
programmed by mistake - and neither gained
nor lost bits whilst in storage. The CHECKSUM
of a device which has programmed wrongly,
gives useful information: if it is too low than the
device has extra bits programmed and was
possibly under-erased. If the CHECKSUM is
too high then the device has bits which will not