Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!uw-beaver!zephyr.ens.tek.com!uunet!mcsun!unido!gmdzi!strobl From: strobl@gmdzi.UUCP (Wolfgang Strobl) Newsgroups: comp.os.msdos.programmer Subject: Re: Detecting an 80486 Message-ID: <3257@gmdzi.UUCP> Date: 28 Aug 90 13:20:15 GMT References: <4562NU013809@NDSUVM1> <1990Aug27.222630.26146@caen.engin.umich.edu> Organization: GMD, Sankt Augustin, F. R. Germany Lines: 37 jal@acc (John Lauro) writes: >> ... >The 386 and I assume 486 do something like that, but only at power up. >Check your manuals on conditions after reset. Too bad all 386/486 >BIOS makers don't stuff that information somewhere.... An instruction >like LMTW would be much better. From page 93, section 9.5, table 6.2 (Register Values after Reset) of "i486(tm) microprocessor, order no. 240440-001, intel): Register Initial Value -------- ------------- ... EDX 0004 + Revision ID The 80386 Programmer's Reference Manual (ISBN 1-55512-022-9) says: Contents of EDX after RESET 31 23 15 7 +-------------------+-----------+-------------+ ! undefined ! DH ! DL ! ! !DEVICE ID ! STEPPING ID ! ! ! 3 ! (UNIQUE) ! +-------------------+-----------+-------------+ I would like to get to the above "Revision ID" without replacing the BIOS of my machine. Are you sure that all BIOS makers throw this information away? I have just started to disassemble a few BIOSes in order to see what they do after reset, but haven't found anything, yet. Wolfgang Strobl #include