mstevens@orca.TEK.COM (Mike Stevens) (11/12/88)
I have a generic Taiwanese 286 AT clone which has motherboard RAM settings for 512K, 640K, and 1MB. I'm using a DTK BIOS with MSDOS 3.21. When I upgraded from 512K to 1MB, I also upgraded the system configuration info to reflect the memory size upgrade (yes, I changed the HW switches too). The system now reports 1MB on powerup (640K base memory, 384K expanded memory). QUESTION: What do I need to do to USE the extra 384K of memory? I tried to set up a ramdisk, but since it isn't extended memory (>1MB), the ramdisk was placed in "low" (<640K) memory. The DOS manuals aren't any help, and I haven't found anything with tells me how/if I can access the 640K - 1M byte space as general purpose RAM. I know that the memory map of the "standard" AT reserves the space for monochrome, EGA, CGA, extended partition gateway, etc. But if the mainboard allows the extra 384K, there must be some use I can put it to. Any ideas?? Thanks for any help .... Mike Stevens
c9c-ba@dorothy.Berkeley.EDU (George Voon) (11/13/88)
In article <2663@orca.TEK.COM> mstevens@orca.TEK.COM (Mike Stevens) writes: >QUESTION: What do I need to do to USE the extra 384K of memory? I >tried to set up a ramdisk, but since it isn't extended memory (>1MB), >the ramdisk was placed in "low" (<640K) memory. The DOS manuals aren't Did you use the /e switch? I also have a generic AT clone with DTK BIOS, but I use MS-DOS 3.3. With the /e switch I can create a RAMDISK in the extra 384K and still have the main 640K free. If it is a problem with DOS 3.21, then upgrading DOS might not be too bad an idea. George Voon
john@wa3wbu.UUCP (John Gayman) (11/13/88)
In article <2663@orca.TEK.COM>, mstevens@orca.TEK.COM (Mike Stevens) writes: > I have a generic Taiwanese 286 AT clone which has motherboard RAM > settings for 512K, 640K, and 1MB. I'm using a DTK BIOS with MSDOS 3.21. > When I upgraded from 512K to 1MB, I also upgraded the system configuration > info to reflect the memory size upgrade (yes, I changed the HW switches > too). The system now reports 1MB on powerup (640K base memory, 384K > expanded memory). > > QUESTION: What do I need to do to USE the extra 384K of memory? I I have not seem many motherboards that set their onboard extra memory to "expanded". This is very strange. Most machines will use the extra memory as "extended" memory. Any software applications which can utilize expanded memory (such as Lotus 123) can and should recognize this extra memory you have. There is a slight misconception that this memory lies between 640K and 1MB. It does not. The extra 384K thats usually on the MB lies ABOVE 1MB. This gets a little confusing but basically the memory addresses that lie between 640 and 1M are used for videa addressing, BIOS, etc. You extra 384 actually *starts* at 1MB and thus extents to 1.408 MB. Since this little window between 640 & 1M is pretty much unavailable for applications, it is transparent to the user. I would verify that your extra memory is indeed "expanded" and not "extended". Try installing a RAMDisk in extended memory by adding the following in your CONFIG.SYS: DEVICE=C:VDISK.SYS 380 512 300 /E <-- This "E" puts it in extended. John -- John Gayman, WA3WBU | UUCP: uunet!wa3wbu!john 1869 Valley Rd. | ARPA: john@wa3wbu.uu.net Marysville, PA 17053 | Packet: WA3WBU @ AK3P