Radio Shack PC-2 TRS-80 - Page 66

After execution of the called program is complete, it can RETurn to the BASIC program.
If you include the optional variable, the X register will be pointing at the location where the variable is stored.
If variable is underfined before you use CALL, an ERROR 7 will occur.
Note
that machine-language programs can only be stored in the Primary memory buffer (see POKE# and PEEK#
for more details on Primary and Alternate memory buffers).
Example
The
following example will produce "reverse video" on the PC-2 Display. Note that the switch from normal video
to reverse video (and back) is much faster than that of a comparable BASIC program.
1 C::
1-'1 1-'
;-,1_,::'
3(1:
70: FOR I = 1 TO 11: FDF~ .J = 1 TO 50: ~~E~'::T .J
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