Radio Shack TRS-80 PC-3 Owner's Manual page 50

locations are reserved for numeric variables A - Z, string variables A$ - Z$, numeric array A(26),
or string array A$(26). The locations are assigned as follows:
Loc. Num. Var. Str. Var. Num. Arr. Var. Str. Arr. Var.
1 A
A$
A(1) A$(1)
2 B B$ A(2) A$(2)
3 C C$ A(3) A$(3)
4 D D$ A(4) A$(4)
23 W W$ A(23) A$(23)
24 X X$
A(24)
A$(24)
25
Y
Y$
A(25) A$(25)
26
Z
Z$
A(26) A$(26)
NOTE: There are only twenty-six locations and you must be careful not to use the same location in two different ways.
If you use location 24 to store a numeric value in X and then try to print X$, you will get an Error 9. Similarly, if you store a
number in A(24) and then store another number in X, you will over-write the first number, but you will not get an error message.
The A( ) and A$( ) arrays are different from all other arrays - - they don't have a zero element. It is possible to use DIM to
make A( ) or A$( ) larger than 26 but, if you do, the first 26 elements will use the reserved locations while the elements from
26 on will be stored in a different part of the memory. The only way that you will notice this, however, is that these 26 special
locations are not cleared when you RUN a program. All other array variables are cleared with each new RUN. By using good
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