On 25/04/2014 5:54 AM, Stanley Daniel de Liver wrote:
On Fri, 21 Feb 2014 05:55:02 -0000, Yousuf Khan
wrote:
I remember I designed an early version of the CPUID program that ran
under DOS. The whole executable including its *.exe headers was
something like 40 bytes! Got it down to under 20 bytes when I
converted it to *.com (which had no headers)! Most of the space was
used to store strings, like "This processor is a:" followed by
generated strings like 386SX or 486DX, etc.

You could make some really tiny assembler programs on x86. Of course,
compiled programs ignored most of these useful high-level instructions
and stuck with simple instructions to do everything.

Yousuf Khan
Did you cater for all the early cpus?

;This code assembles under nasm as 105 bytes of machine code, and will
;return the following values in ax:
;
;AX CPU
;0 8088 (NMOS)
;1 8086 (NMOS)
;2 8088 (CMOS)
;3 8086 (CMOS)
;4 NEC V20
;5 NEC V30
;6 80188
;7 80186
;8 286
;0Ah 386 and higher

I don't know if I still have my old program anymore, but I do remember
at that time it could distinguish 386SX from DX and 486SX from DX as well.

Yousuf Khan