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SPEAKER: What you have here is a
listing of an early piece of software

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written by Bill Gates and Paul
Allen, the founders of Microsoft.

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The code is interesting for two reasons.

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First of all, it became
Microsoft's first product,

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which was an interpreter for
the basic programming language.

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>> And secondly, this was
one of the first attempts

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to create an interpreter so ordinary
people could use personal computers.

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So, bill gates was an
undergraduate at Harvard.

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I started teaching at Harvard 1974.

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This was done in 1975.

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>> So, it was early in his
career in early in my career.

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I actually taught Bill in
a course around this time.

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Paul Allen was not a
Harvard student, but he

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had been a high school
classmate of Bill Gates.

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If you come and look
at the listing, you'll

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actually find a third
name, Monte Davidoff,

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who was Gates's classmate
here at Harvard.

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>> Here's an interesting comment up here.

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It says "in 4k can delete square root
but for loops should still work."

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So what that means is that there was
two ways to compile this program.

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One was to run on a version
of this Altair computer

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that only had 4k words of
memory, 4,096 words of memory.

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>> But the big version had 8k.

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And so what this says
that in the 4k version

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you had to delete some
code to make it fit.

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And one of the things
that would be deleted

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would be the square root routine.

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But apparently the
for loops should still

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work even when you were
compiling down for just

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the 4k version of the computer.