TI Logo II

This was the second attempt by TI to implement LOGO, a language they had worked on with its inventor Seymour Papert (see his book "Mindstorms").

LOGO II like LOGO I requires memory expansion.

The graphics are produced by the language constantly redefining the usual character set, with a limit on the number of characters to redefine ("Out of Ink" error) and the use of color.

LOGO 1 had a number of bugs which were addressed in LOGO II but at the last minute a few bugs were discovered to have been introduced, as usual with software debugging.

LOGO 2 contains a new tiny bug...the primitive MS (makeshape) which works in a defined procedure in LOGO 1 can only be used in direct mode in LOGO 2. Thus one of the sample procedures supplied will not run.

Sample of a TI Logo routine:

TO TREE :SIZE :ANGLE :LEVEL
IF :LEVEL = 0 THEN STOP
LEFT :ANGLE
FORWARD :SIZE * 2
TREE :SIZE :ANGLE :LEVEL - 1
BACK :SIZE * 2
RIGHT 2 * :ANGLE
FORWARD :SIZE
TREE :SIZE :ANGLE :LEVEL - 1
BACK :SIZE
LEFT :ANGLE
END
TO WILLOW
TELL TURTLE
PENUP
BACK 24
PENDOWN
TREE 8 15 8
BACK 24
END

NOW key in WILLOW Not an unpleasant result.