Path: utzoo!attcan!uunet!lll-winken!lll-lcc!mordor!joyce!ames!ncar!gatech!udel!rochester!pt.cs.cmu.edu!b.gp.cs.cmu.edu!ralf From: ralf@b.gp.cs.cmu.edu (Ralf Brown) Newsgroups: comp.sys.ibm.pc Subject: Re: MS-DOS Multitaskers Message-ID: <2279@pt.cs.cmu.edu> Date: 15 Jul 88 02:44:53 GMT References: <10904@cisunx.UUCP> <5404@ecsvax.uncecs.edu> <3614@peora.ccur.com> Sender: netnews@pt.cs.cmu.edu Distribution: na Organization: Carnegie-Mellon University, CS/RI Lines: 22 In article <3614@peora.ccur.com> joel@peora.UUCP writes: }In article <5404@ecsvax.uncecs.edu>, gas@ecsvax.uncecs.edu (Guerry A. Semones) } to do BIOS writes rather than direct screen writes. Can Desqview really } window stuff that bypasses the BIOS? I can't think of any any handy } way to intercept the writes to the display memory on a non-386 based } machine. Of course I'm not a hacker when it comes to my PC. While DESQview can't intercept direct writes on less than a 386, more and more programs are DESQview-aware. Any program which writes directly to screen memory has to determine where the screen memory is and store that value away somewhere. By adding ten lines of assembler or equivalent HLL code, it is possible to make the program write into DESQview's shadow buffer, which can then be windowed. There is even a small TSR available that helps in patching in DESQview-awareness. You change (with DEBUG) the actual instruction that loads the screen address into an interrupt call, and the TSR replaces the value with DESQview's buffer. -- {harvard,uunet,ucbvax}!b.gp.cs.cmu.edu!ralf -=-=- AT&T: (412)268-3053 (school) ARPA: RALF@B.GP.CS.CMU.EDU |"Tolerance means excusing the mistakes others make. FIDO: Ralf Brown at 129/31 | Tact means not noticing them." --Arthur Schnitzler BITnet: RALF%B.GP.CS.CMU.EDU@CMUCCVMA -=-=- DISCLAIMER? I claimed something?