Radio Shack TRS-80 Model 4 - Page 165

A! = -1234
Stores - 1234.000 in A!.
Double to sing Ie precision
This involves converting a number with up to 16 significant digits into
a number with
no more than seven digits. BASIC rounds the number
to seven significant digits. Before printing
it, BASIC rounds it off to six
digits.
Examples
A! = 1.234587880124587
stores 1.234568 in A!. However, the statement:
PRINT A
displays the value 1.23457, because only six digits are displayed. The
full seven digits are stored
in memory.
A I = 1.3333333333333333
stores 1.333333 in A!.
Single to double precision
To make this conversion, BASIC simply adds trailing zeros to the
single-precision number.
If the original value has an exact binary
representation
in single-precision format, no error is introduced. For
example:
A# = 1.5
stores 1.5000000000000 in A#, since 1.5 does have an exact binary
representation.
However, for numbers which have
no exact binary representation, an
error is introduced when zeros are added. For example:
A# = 1. 3
stores 1.299999952316284 in A#.
Because most fractional numbers do not have an exact binary
representation, you should keep such conversions out of your
programs. For example, whenever you assign a constant value to a
double-precision variable,
you can force the constant to be double
precision:
A# = 1.3# A# = 1.30
both store 1.3 in A#.
Here is a special technique for converting a single precision value to
double precision, without introducing
an error into the double-precision
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