Math Coprocessor Not Installed

Problem

system error 90-- math co-processor not installed. Happens with XL 2.2 or earlier when used with MacNail construction estimating software.

Diagnosis

occurs with Mac LC and any other Macintosh that has a 68020, 68030 or 68040 chip without a math co-processor, when using Excel 2.2 or earlier

NOTE-- This answer applies to our retired MacNail construction software, and does not apply to modern computers. MacNail has been replaced by Goldenseal estimating software and accounting software for Macintosh and Windows.

Solution

try this temporarily: hold down option key when they start up excel.
more long term fix: call Microsoft and request latest version of 2.2 (2.2a or b or something like that). With very new Macs, may need to upgrade to a newer version of excel.

Comments

sloppy programming on Microsoft's part. For a while macs either had a 68000 chip and no math coprocessor, or a 68020/030 chip and a coprocessor-- so MS used the presence of the coprocessor to determine which chip type was being used. Newer macs with no coprocessor but with fast chips violate that assumption.

Entered 11/3/93 by Dennis. Updated 11/12/2010.