sonny@charybdis.harris-atd.com (Bob Davis) (11/13/90)
In what I read about designing TSRs, warnings are issued about monitoring the "InDOS" flag and/or "DOSOK" (Int28h) to determine when DOS function calls can safely be made. The impression usually left on me by the authors of this information is that BIOS calls are OK without such monitorings (as opposed to DOS calls - which are verboten). Is this true? Is BIOS code reentrant? In TSRs, may I safely use ALL Interrupts below 20h without checking on ANY such flags or indicators? Is reentrancy of concern? Is it ONLY when I need to use Interrupts above 20h that checks to avoid reentrancy are necessary? Thanks. ______________________________________________________________________________ Bob Davis, UofALA'66 \\ INTERNET : sonny@trantor.harris-atd.com | _ _ | Harris Corporation, ESS \\ UUCP : ...!uunet!x102a!trantor!sonny |_| |_| | | Advanced Technology Dept.\\ AETHER : K4VNO |==============|_/\/\/\|_| PO Box 37, MS 3A/1912 \\ VOICE : (407) 727-5886 | I SPEAK ONLY | |_| |_| | Melbourne, FL 32902 \\ FAX : (407) 729-2537 | FOR MYSELF. |_________|