diff --git a/NOTES/Intel DIV behavior/Pentium 133MHz (1996) test results (1).txt.xz b/NOTES/Intel DIV behavior/Pentium 133MHz (1996) test results (1).txt.xz new file mode 100755 index 000000000..034e6cc37 Binary files /dev/null and b/NOTES/Intel DIV behavior/Pentium 133MHz (1996) test results (1).txt.xz differ diff --git a/NOTES/Intel DIV behavior/README.TXT b/NOTES/Intel DIV behavior/README.TXT new file mode 100644 index 000000000..14746a0af --- /dev/null +++ b/NOTES/Intel DIV behavior/README.TXT @@ -0,0 +1,11 @@ +Collected here are "grind" dumps of the DIV instruction on various Intel processors. + +Officially, DIV is not really supposed to modify any flags by Intel documentation. +But, at least on Pentium and lower processors, the flags do in fact change. +And in some cases, how these flags change can mean the difference between correct +and incorrect CPU detection by DOS programs (i.e. detecting the difference between +an Intel 386 vs a NexGen 5x86). + +To preserve prior weird behavior, dumps of the DIV instruction's behavior are provided +here. + diff --git a/NOTES/Intel DIV behavior/xzview.sh b/NOTES/Intel DIV behavior/xzview.sh new file mode 100755 index 000000000..34a107a47 --- /dev/null +++ b/NOTES/Intel DIV behavior/xzview.sh @@ -0,0 +1,3 @@ +#!/bin/bash +xz -c -d "$1" | less - +