rdas@hatter.Tops.Sun.COM (Robin Das) (06/02/89)
Does anyone know how to determine how much extended memory is available on a 286 or 386 processor?
ray@philmtl.philips.ca (Raymond Dunn) (06/02/89)
In article <630@hatter.Tops.Sun.COM> rdas@hatter.Tops.Sun.COM (Robin Das) writes: >Does anyone know how to determine how much extended memory is available on >a 286 or 386 processor? RTFM BIOS call INT 15 with AH = 88h returns carry set if error, else number of 1K blocks above 1Meg as stored in the CMOS and checked by the BIOS during Power On Self Test. -- Ray Dunn. | UUCP: ..!uunet!philmtl!ray Philips Electronics Ltd. | TEL : (514) 744-8200 Ext: 2347 600 Dr Frederik Philips Blvd | FAX : (514) 744-6455 St Laurent. Quebec. H4M 2S9 | TLX : 05-824090
rob@conexch.UUCP (Robert Collins) (06/03/89)
In article <630@hatter.Tops.Sun.COM> rdas@hatter.Tops.Sun.COM (Robin Das) writes: >Does anyone know how to determine how much extended memory is available on a 286 or 386 >processor? There are a couple of ways to do it: 1) There is a CMOS word available for how much RAM is currently in the RAM Pool. The current RAM pool is defined as how much RAM is available after VDISK, DISK_CACHE and other utilities that use, or reside in extended memory. 2) There is another CMOS word available for how much RAM is in the system. This is regardless of VDISK et al. 3) Do it the way the SYSTEM BIOS does it during POST. This is very dangerous since in order to determine how much ram is there, you must look for ram being written to 2 locations (a non-existant address line). And guess where you will overwrite using this method? Right over your interrupt vectors. I'm sure some other users can give you the CMOS locations, as I'm too lazy right now to look them up. -- "Worship the Lord your God, and serve him only." Mat. 4:10 Robert Collins UUCP: ucbvax!ucivax!icnvax!conexch!rob HOMENET: (805) 523-3205 UUCP: uunet!ccicpg!turnkey!conexch!rob WORKNET: (805) 378-7901