41CL User Manual
© 2019, Systemyde International Corporation
41
without modifying the contents of the ALPHA register. Only the transfer of both bytes of
a word counts as a successful transfer. If the transfer times out between the first and sec-
ond byte of a word transfer, or the receiver overflows on either byte of a word transfer the
transfer is deemed unsuccessful.
Miscellaneous Functions
There is only one miscellaneous function in the
41CL Extra Functions
. Most users will
never need it. Once you move to the
41CL Extreme Functions
the MMU programming
can be protected from accidental programming.
YFNS?
Executing
YFNS?
(
Read 41CL Extra Functions Location
) polls the logical memory for
the current location of the
41CL Extra Functions
. The page where the
41CL Extra Func-
tions
reside is returned in the X register as a decimal number in the range
6
through
15
,
corresponding to Pages 6 through F. This information can be used to prevent accidentally
overwriting the
41CL Extra Functions
when reprogramming the MMU.
Image Database Functions
The Image Database Functions (there is only one in the
41CL Extra Functions
) allow the
user to search the Image Database. A more complete set of Image Database functions is
available in the
41CL Extreme Functions
.
IMDB?
(module identifier or Page address in ALPHA register)
Executing
IMDB?
(
Search Image Database
) searches the selected Image Database for a
match, using the either a module identifier or a page address, and returns the correspond-
ing database information.
This function tests that the Image Database is present, and returns with a
NO IMDB
error message if this is not true.
The figure below shows the formatting for a module identifier and page address:
