james@bigtex.cactus.org (James Van Artsdalen) (01/29/89)
In <3945@alvin.mcnc.org>, somers@mcnc.org (Robert W. Somers) wrote: > I have a PC BRAND 286/20 with the Chips & Technologies " NEAT " set > and AMT BIOS. > I have but one complaint, [...] there is no information as to how to > use the setup mode to configure the machine for additional memory, > wait states, shadow, etc,.. Well, I don't know anything about AMT BIOS, but I would assume that the BIOS would auto-configure at bootup to whatever memory is available on the motherboard. As far as changing the NEAT setup, I strongly advise against it. The best you are likely to do is to make the machine go away. Many changes will result in the memory map being scrambled. Unless you can make these changes in ROM in POST, you're not likely to get lucky. Other things to keep in mind is that even with documentation it is tricky to program that NEAT chipset, since the "reserved" bits often do unexpected things. Finally, it seems unlikely that PC Brand would have deliberately chosen to use a slower configuration unless the faster configuration proved unreliable. -- James R. Van Artsdalen james@bigtex.cactus.org "Live Free or Die" DCC Corporation 9505 Arboretum Blvd Austin TX 78759 512-338-8789
jallen@netxcom.UUCP (John Allen) (02/07/89)
In article <13335@bigtex.cactus.org> james@bigtex.cactus.org (James Van Artsdalen) writes: >In <3945@alvin.mcnc.org>, somers@mcnc.org (Robert W. Somers) wrote: > >> I have a PC BRAND 286/20 with the Chips & Technologies " NEAT " set >> and AMT BIOS. > >> I have but one complaint, [...] there is no information as to how to >> use the setup mode to configure the machine for additional memory, >> wait states, shadow, etc,.. > >Well, I don't know anything about AMT BIOS, but I would assume that >the BIOS would auto-configure at bootup to whatever memory is >available on the motherboard. I suspect that this is the AMI BIOS, not "AMT". If so, it's likely to be about the same as that found in my 286-16 Motherboard (NEAT chipset). In which case, the BIOS decidedly does NOT optimize the chipset, and in the case of shadow-ram versus extended addressing, how could it? Only you know what you want to do with the extra memory. My motherboard came with LOTS for detailed documentation about the NEAT chipset, so I suggest that Robert get in touch with his dealer. Using this information, I was able to improve system performance from 15.5 to 18.7 "nortons", and improve video performance (shadow ram) by about 200%. >As far as changing the NEAT setup, I strongly advise against it. The >best you are likely to do is to make the machine go away. Many >changes will result in the memory map being scrambled. Unless you can >make these changes in ROM in POST, you're not likely to get lucky. While making these changes is not for the faint-hearted, it is certainly within the scope of useful tuning. If you do screw up, (as I have), just power down and bleed off any stored charge in the chipset for two or three minutes. This has (several times) returned my machine to an operative state. >Other things to keep in mind is that even with documentation it is >tricky to program that NEAT chipset, since the "reserved" bits often >do unexpected things. Yes, it can be tricky. Why would you want to play with the reserved bits, though? >Finally, it seems unlikely that PC Brand would have deliberately >chosen to use a slower configuration unless the faster configuration >proved unreliable. This is a valid point - relative to wait states, perhaps - but doesn't reflect the fact that you can also modify shadow ram, BIOS mapping, bus clock speed, bus waits, DMA waits, and a few other things that are dependent upon your own configuration, and not just the parts that you may have purchased from PC Brand. John Allen ======================================================================= NetExpress Communications, Inc. usenet: uunet!netxcom!jallen 1953 Gallows Road, Suite 300 phone: (703) 749-2238 Vienna, Virginia, 22180 telex: 901 976 =======================================================================