41CL Calculator Manual
© 2019 Systemyde International Corporation
71
other images, and the 41CL takes advantage of this space. So the database search
functions treat a type digit of 4 as 24K words in length, and return search results
accordingly.
Digit 0 of the first word and digits 1 and 0 of the second word of a database entry hold the
starting memory address for the image referenced by the module identifier. This is a phys-
ical address that can be in either Flash memory or RAM. Note that if the starting address
is 000, along with a type digit of 0, the entry is considered a null entry.
Digit 3 of the second word of a database entry is used only by the
41CL Extreme
Functions
if there are restrictions on where the image can be placed, according to the
table below:
word2
digit 3
Page Restriction
0
No Restriction
1
Not Pluggable
2
Page 0 only
3-F
Page 3-F only
Digit 2 of the second word of a database entry is used only by the
41CL Extreme
Functions
to modify the type field, according to the table below:
word2
digit 2
Type Modification
0
No Modification
1
Modify type 3 to 12K (3 pages)
Digits 1 and 0 of the third and fourth words of a database entry hold the middle two char-
acters of the module identifier. This allows an address-based search of the database to
return the full module identifier. It would also allow the
PLUG
functions to check for the
full module identifier, but this feature was not implemented to preserve backwards-com-
pa
t
i
bi
l
i
t
y.
The
s
e
t
wo wor
ds
c
a
n us
e
e
i
t
he
r
t
he
“
di
s
pl
a
y”
e
nc
odi
ng,
whe
r
e
A
-
Z
are
encoded as 0x41-
0x5A,
or
t
he
“
a
s
s
e
mbl
y
l
a
ngua
ge
”
e
nc
odi
ng,
whe
r
e
A
-
Z
are encoded
as 0x01-
0x1A.
Al
l
of
t
he
or
i
gi
na
l
e
nt
r
i
e
s
i
n t
he
I
ma
ge
Da
t
a
ba
s
e
us
e
t
he
“
a
s
s
e
mbl
y
l
a
ngua
ge
”
e
nc
odi
ng,
whi
l
e
a
ny
us
e
r
-
a
dde
d
e
nt
r
i
e
s
wi
l
l
a
l
wa
ys
us
e
t
he
“
di
s
pl
a
y”
e
nc
odi
ng.
As mentioned previously, entries in the Image Database are addressed using the first and
fourth characters of a module identifier. Each of these characters must be translated to a
5-bit field to create an address to index the database. The table below shows the
translation algorithm.
