Dataman S4 User Manual
Page 24
DATAMAN S4 MANUAL
24 LIB KEY
LIB KEY
LIB is used to COPY new software from a
"LIBRARY ROM" in the ZIF socket to the
Transient Program Area. The program runs
automatically when it has loaded.
When you see the message, place a LIBRARY
ROM in the front panel socket and press
ENTER. To abort the command, press
ESCape.
The LIBRARY instruction does not move all the
code in the LIBRARY ROM into the TPA area:
if it did the stack would be overwritten in the
process and the program would crash. Instead
the ROM contains pointers which show which
code must be moved. Each pointer is prefixed
by a 42 byte: 42 is used to indicate that there is
a block to be copied (Why 42? Well, any byte
could be used and 42 has no real significance,
except to the software engineer who is a
Douglas Adams fan....) The four bytes
following give START and END addresses of
the block. If there is another block then follows