Article View: comp.os.msdos.programmer
Article #6199Re: CS and IP problem
From: Walter Bright
Date: Sun, 27 Dec 1992 00:16
Date: Sun, 27 Dec 1992 00:16
15 lines
923 bytes
923 bytes
In article <1g7623INNli3@mercury.kingston.ac.uk> cs_e404@ceres (Sean Batten) writes: /Now, I can see now you save the AX,BX,CX,DX,DS,ES,SS and Flags, you /simply store them straight away when you switch tasks, but _HOW_ do you /save the CS and IP registers since their values will have changed when /the tasks switched????? When a CALL or INT or external interrupt occurs, the CS and IP are saved on the stack. In fact, a CALL is equivalent to: PUSH CS PUSH offset L1 JMP subroutine L1: ... So, you save CS and IP by looking at the stack.
Technical Details
Message-ID:
<1544@nazgul.UUCP>Path:
arc1-ca.pugleaf.net!sparky!uunet!pilchuck!fnx!nazgul!brightReferences:
<1g7623INNli3@mercury.kingston.ac.uk>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!sparky!uunet!pilchuck!fnx!nazgul!bright From: bright@nazgul.UUCP (Walter Bright) Newsgroups: comp.os.msdos.programmer Subject: Re: CS and IP problem Message-ID: <1544@nazgul.UUCP> Date: 27 Dec 92 00:16:05 GMT References: <1g7623INNli3@mercury.kingston.ac.uk> Reply-To: bright@nazgul.UUCP (Walter Bright) Organization: Zortech, Seattle Lines: 15