EM87 coprocessor emulator and Intel copyrighted library in it.

[george]

Once upon a time there was a very decent real mode 8087 emulator called EM87 which still can be downloaded around the net including http://ftp.sunet.se/pub/simtelnet/msdos/emulate/em87v1_3.zip simtel mirrors.

This emulator was sold by Ron Kimball as is written in the doc file in the archive. The emulator itself is a packed TSR COM file that is easily unpacked by CUP386 and probably other tools. When unpacked you can see at file offset 210h the string "(C) 1981,1982 INTEL CORP". The emulator was very precise and I believe a real Intel code was used in it. The mystery is what library/code/source was used in it? How this person obtained it? Is there any access to the source code of this math lib after so many years?

 

[reenigne]

I came across http://bitsavers.trailing-edge.com/...-001_8087_Support_Library_Reference_Nov83.pdf which mentions an 8087 emulation library that could be the one linked into this program. No sign of a download or source though I'm afraid!

 

[RoadRanger]

Hey, I'm the Ron Kimball (author of EM87).
The library was included with the Intel assembler back then.
I did have to "patch" it as it was "listening" on a different interrupt than the IBMPC used for floating point exceptions.
Obviously it was assembled with that assembler so it was legal to use the library

 

[george]

Hi. That's rather interesting. Which assembler was that? I guess the library was well documented by Intel?

 

[george]

The library was called 8087 Support Library. Here is the manual for it and it seems that library was not part of the Intel ASM86:

http://bitsavers.trailing-edge.com/pdf/intel/MDS3/121725-001_8087_Support_Library_Reference_Aug81.pdf

It seems I asked about that and later 387 libraries here but nobody appears to have these libraries, its amazing you managed to get the library back in the day along with the manual? https://forum.vcfed.org/index.php?threads/debug-and-the-8087-fpu.13438/post-871908

According to the notes after this extremely fascinating work the 8087 library cost back in the day $1250.

Die analysis of the 8087 math coprocessor's fast bit shifter

Floating-point numbers are very useful for scientific programming, but early microprocessors only supported integers directly. 1 Although...

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