This is for real. It was actually sent.

9th July 1986

Mr. James Meadlock

President

Intergraph Corporation

One Madison Industrial Park

Huntsville, AL 35807-4201

Dear Mr. Meadlock:

I was recently asked by one of our customers to comment on the attached memo from Mr. Ken Bado of your company. Since the memo contains a serious misstatement of the facts regarding our product, I felt I should bring it to your attention immediately.

AutoCAD maintains all of its coordinates internally in 64 bit floating point, adhering to the IEEE standard for double precision floating point (IEEE Std 754-1985). This delivers more than fourteen decimal places of accuracy. No physical constant is known to an accuracy of fourteen decimal places. That accuracy is more than adequate to position objects anywhere in the entire solar system (encompassing the orbit of Pluto) to within one centimetre.

Mr. Bado does not grasp the distinction between decimal places and bits. As I understand it, Intergraph is an integer-based system with 32 bits of accuracy. This provides for an accuracy of 4.2 billion units and a dynamic range from zero to 4.2 billion. AutoCAD's IEEE standard floating point provides a 52 bit mantissa, allowing an accuracy of 4.5 quadrillion units. This is more than a million times as accurate as Intergraph's system. In addition floating point gives us a dynamic range of plus or minus 10**308, which is over one billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion billion times that of Intergraph, and obviates the need for the user to explicitly establish a scale factor.

Could somebody in your company explain this to Mr. Bado? Would you be so kind as to send me a copy of the memo to your sales force which corrects his misstatements?

Whether you choose to denigrate competitive products is your business. But if you do so choose, it helps to get the facts right.

By the way, what's an ``iteraction''?

Sincerely,

*John Walker*

AUTODESK, INC.

John Walker, President

Editor: John Walker