Commodore PET User Manual page 86

LEN(A$+B$) Returns the combined length of the two strings.
LEFT$(ST$,l) Returns the leftmost character of the string ST$.
The following functions constitute the format function group:
SPC Space over.
TAB Tab over.
POS Next print position.
You will use format functions to display or print information using any
desired format. SPC and TAB take a single numeric argument. POS uses a dummy
argument of
O.
Examples:
SPC(10)
TAB(A)
Move cursor over 10 spaces.
Move cursor to column A+l.
PEEK
TI$,TI
FRE
Finally there are some "system" functions vou will not use until vou are a
more experienced programmer. The system function group includes these
functions:
Fetches the contents of a memory byte.
Fetches System Time, as maintained by a program clock.
Returns available Free Space - the number of unused
read/write memory bytes.
SYS Transfers to Subsystem.
USR Transfers to User Assembly Language Program.
System functions are useful only in certain classes of special programming.
They are not used in typical PET programs.
PET BASIC also allows you to define your own functions with the DEF
FN function.
These functions are ail described in detail in Chapter 4.
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