Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site burl.UUCP
Path: utzoo!watmath!clyde!burl!wjb
From: wjb@burl.UUCP (Bill Buie)
Newsgroups: net.micro.cbm
Subject: VIC20 BASIC bug (?)
Message-ID: <596@burl.UUCP>
Date: Tue, 4-Dec-84 09:46:40 EST
Article-I.D.: burl.596
Posted: Tue Dec  4 09:46:40 1984
Date-Received: Wed, 5-Dec-84 00:18:02 EST
Organization: AT&T Technologies; Burlington, NC
Lines: 49

--
My nephew has a VIC20, and I am (shudder) trying to teach him some
fundamentals of programming in BASIC.  There is a problem: his
machine isn't acting right.  Now I'll admit to not being terribly
familiar with the language (I play with my C64 in assembler), but
what would you expect the following code to do?

110 PRINT"THIS IS A PRINT STATEMENT"
120 PRINT"THIS IS ANOTHER PRINT STATEMENT"
130 PRINT"THIS IS YET ANOTHER PRINT STATEMENT"
140 PRINT
150 INPUT"WHAT DO YOU SAY TO THAT";I$
160 IF I$ = "" THEN 150
170 PRINT I$

My C64 executes this the way I'd expect; if the return is pressed
after "WHAT DO YOU SAY TO THAT?" without entering at least one
character, line 150 is executed again, prompting the user with
another "WHAT DO YOU SAY TO THAT?" and so on until the user finally
enters something.

But on my nephew's VIC20, if the return is pressed without typing
anything else, the machine produces the following session:

THIS IS A PRINT STATEMENT
THIS IS ANOTHER PRINT STATEMENT
THIS IS YET ANOTHER PRINT STATEMENT

WHAT DO YOU SAY TO THAT?

WHAT DO YOU SAY TO THAT?
READY

My nephew has told me over the phone that he thinks all the GOTO's
are working like that; if the instruction pointer is at line 40,
which says GOTO 10, my nephew predicts that 10 will be executed and
then line 50 will be executed.  I have not had an opportunity to
test this hypothesis myself.  Need I say that I am annoyed and
perplexed?  I figured there were two possiblities; either his
keyboard is broken in some strange way, or he has an absolutely
bizarre implementation of BASIC.  I thought I'd rather quiz the net
first (as opposed to quizzing a $repairman$); has anybody ever seen
anything like this?

All replies welcomed.
-- 

				--Bill Buie
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