Windows 95 Secrets (4th Edition)

home *** CD-ROM | disk | FTP | other *** search

/ Windows 95 Secrets (4th Edition) / Windows95Secrets4thEdition.iso / utility / configur / cmossave / cmos.txt < prev next >

Wrap

Text File | 1995-05-11 | 13.3 KB | 372 lines

CMOS.TXT Last updated 1995 May 11 by Roedy Green Purpose ******* 1. Naive users sometimes meddle with CMOS settings. We need a fast way to put the scores of subtle CMOS configuration settings back the way they were. 2. Power surges can corrupt CMOS. We need a way for a naive user to quickly restore all the CMOS settings. 3. If the battery fails, the contents will be lost. We need a way to restore a known working CMOS configuration. 4. You may want to alter some obscure CMOS setting and you don't have a program to set it. 5. CMOSRest can also be used to toggle between two CMOS configurations, for example with and without a removable hard drive installed. 6. CMOSChk can detect subtle corruption to CMOS, as might be caused by a rogue program or a virus, something that might slow your machine or make it unreliable. 7. CMOSSave can create a backup of your CMOS on floppy. This way you may safely experiment with CMOS settings. You can always get back to where you started by using CMOSRest to restore the original settings. Any time you meddle with the computer innards, you might accidentally disconnect the battery, losing CMOS. CMOSSAVE lets you put it back the way it was. Syntax ****** There are three utilities in the CMOS suite: CMOSSAVE.COM A:Myfile.Sav IF ERRORLEVEL 1 GO TO Trouble - saves a copy of CMOS in a file on hard disk or floppy. CMOSREST.COM A:MyFile.Sav IF ERRORLEVEL 1 GO TO Trouble - restores CMOS from a file on hard disk or floppy. CMOSCHK.COM A:MyFile.Sav IF ERRORLEVEL 1 GO TO FixIt - checks that CMOS has not been meddled with since the last CMOSSAVE. Compares CMOS with a file on hard disk or floppy. Hints on Use ************ There are three ways you can use the suite manually, automatically, and with a rescue diskette. 1. Manually. Copy your CMOS to a bootable floppy with: CMOSSAVE.com A:\CMOS.SAV If ever your cmos becomes corrupted, correct it by booting from floppy and typing: CMOSREST.com A:\CMOS.SAV Then rebooting. Don't bother with CMOSCHK.com. 2. With a rescue diskette. Prepare a bootable floppy with an autoexec.bat that invokes the following commands to correct most CMOS and hard disk problems: CMOSREST A:\CMOS.SAV BOOTREST A:\BOOT.SAV CHKDSK C:/F SYS C: COPY A:\COMMAND.COM C:\ COPY A:\COMMAND.COM C:\DOS 3. Automatically. Insert the line: CALL C:\BAT\CHKCMOS.BAT in your autoexec.bat. This bat file uses CMOSCHK.com to compare the contents of CMOS with what it should be. If there is a mismatch, it will invoke CMOSREST.com to put it back. then REBOOT.com to try again. Note this method will not be able to recover if the CMOS is badly damaged. You will have to revert to method 1 or 2. Note that CHKCMOS.BAT needs to be configured with a text editor before use. Belt And Suspenders ******************* Do a CMOSSAVE both to hard disk and to floppy. The hard disk copy can be used for quick restores built into your AUTOEXEC.BAT file. CMOSCHK.COM C:\MyCMOS.Sav IF ERRORLEVEL 1 CMOSREST.COM C:\MyCMOS.Sav At that point you must reboot before the restored cmos settings take effect. See CHKCMOS.BAT for a realistic way to handle this. You will will have to tune that BAT file a little to suit your machine, either by replacing the %XXX% or inserting SET commands. Sometimes CMOS will be so badly damaged the hard disk parameters will be corrupt and your hard disk will stop working. In that case you will have to revert to using the floppy copy. Whenever you change your CMOS setting deliberately, you need to redo the CMOSSAV.COM. However USE A NEW FILENAME, so that you can easily revert to the old version if your new settings do not pan out. How it works ************ CMOSSAVE.COM simply copies the 128 byte contents of the CMOS bytes to a file. CMOSREST.COM copies them back. CMOSCHK compares them with the file contents. If they are not equal it sets ERRORLEVEL 1. CMOSREST does not touch bytes 0 to 09 and 32h because these are volatile -- they contain the date and time. Similarly CMOSCHK, does not panic if any of these volatile bytes differ. However, CMOSSAVE saves all 128 bytes, so that you can browse the generated file with a hex editor to learn more about how CMOS works. You could even patch the CMOS.SAV file to get special effects. Because CMOSSave also saves the extended CMOS bytes, CMOSRest will restore the esoteric options like shadow RAM, wait states, processor clock speed, HMA enable etc. These is no need to calculate checksums, since the checksum is saved and restored just like any other CMOS byte. We have included a sample file called CHKCMOS.BAT which can be inserted in your AUTOEXEC.BAT which uses all three utilities. Using it requires fairly good knowledge of BAT files to customize it for your needs. How CMOS is used **************** CMOS is battery backed RAM that stores configuration information when the power is off. It is on my top ten worst ideas list of all time. The problem is, CMOS is far too easily corrupted, by programs, power or meddling. See CMOS.OFS for a detailed list of what each byte in the CMOS is used for. Troubleshooting *************** Sometimes your CMOS will be so wrecked you cannot even get your machine limping enough to run CMOSREST from floppy. In that case you must clear CMOS. Do this on AMI BIOSes by holding down the INS key, powering off, powering on, then releasing the INS key. In the worst case, remove the battery and let the capacitance on the board drain overnight to clear it. On some CMOSes you can clear CMOS by selecting universal default settings. You can then get a bare bones CMOS configured -- that just has the floppies right. From there you can run CMOSREST.COM. What is considered volatile and what is not, might vary for different boards. If you have trouble restoring, DO NOT DESPAIR. All is recorded. A variant of the CMOSREST program could get you back. All you need do in make a slight modification to the assembler source VOLATILE routine that decides which bytes to consider volatile. Even a very junior MASM programmer could make that modification for you. If you use SSTOR, I suspect it makes it look as though it had modified CMOS. If you boot without the SSTOR driver, CMOS will appear to have changed because SSTOR is not doing its standard trickery. The TURBO setting is part of CMOS. If you accidentally turn turbo mode off, CMOS will appear to be changed, and CMOSCHK will complain. To clear the problem, set turbo back on and allow the CMOSCHK to restore CMOS. *************************************************************** *************************************************************** We repeat: CMOSREST won't do you a lick of good unless you run CMOSSAVE BEFORE you have trouble. Make sure you have copies of CMOS.SAV both on hard disk and on floppy. *************************************************************** *************************************************************** There is a companion program called BOOTSAVE that works in a similar way to protects your boot track from damage by rogue programs or viruses. Again, you must use it BEFORE you have trouble. When you register, I will send you a copy of BOOTSAVE, and REBOOT, which are useful adjuncts to CMOSSAVE. CMOSREST does not take effect until you REBOOT!! Verification Fire Drill *********************** CMOSSave and CMOSTRest have internal checks to warn you if they are not functioning. However, you can assure yourself they are working properly by using CMOSSave, then changing some minor setting in CMOS (e.g. to add an extra unneeded wait state), then use CMOSChk to detect the "damage" then CMOSRest to restore the CMOS back the way it was. If all is working correctly, the minor change should be undone. False Alarm CMOSCHK Corruption Messages *************************************** Some non-standard BIOSes have additional volatile portions that CMOSCHK does not know about. It will report false corruptions. There are three ways you can handle the problem: 1. Send us a screen print of what CMOSCHK is saying. We will send you a custom version with those false mismatches considered as volatile bytes. You must register if you want this service. 2. Modify the "VolatileList" line in CMOS.ASM yourself to include the extra offsets your BIOS is treating as volatile. Then reassemble. CmosChk.com will give you a list of offsets where it thinks there are mismatches. It is up to you to determine which ones you think are false alarms. 3. Simply avoid using CMOSChk. Just use CMOSSAVE and CMOSREST. Most of the time damaged CMOS is fairly obvious. Author ****** CMOSSAVE, CMOSREST and CMOSCHK are copyrighted but may be freely used for any purpose except military. If you pass the files on, PLEASE PASS ON THIS DOCUMENTATION TOO. Please report bugs and problems to: Roedy Green Canadian Mind Products #601 - 1330 Burrard Vancouver BC Canada V6Z 2B8 (604) 685-8412 Electronic mail users can contact me via internet: roedy@bix.com Harvey Fishman wrote a pair of programs similar to CMOSSAVE and CMOSREST, but to the best of my knowledge, never released them. Support is available only to registered users. Shareware Status **************** CMOSSAVE CMOSREST and CMOSCHK are shareware. If you like them send $20 US or Canadian to: CMOSSAVE Roedy Green Canadian Mind Products #601 - 1330 Burrard Vancouver BC Canada V6Z 2B8 (604) 685-8412 Sorry we can no longer accept credit cards. The company was wiped out by criminals and we are just a thread of our former selves. Personal cheques are fine. Please make them payable to Canadian Mind Products. Please mention the program title since we sell many other products. We in return will send you the latest version complete with MASM source for CMOSSAVE, CMOSREST, CMOSCHK, REBOOT, BOOTSAVE, BOOTREST and BOOTCHK. We will also include a 1.2 MB or 1.44 diskette (please specify your preference) full of the source code for the complete CMP suite of other utilities. If you don't register, and continue to use CMOSSAVE, we will not do anything mean to you. We don't even want you to feel unusually guilty. It is theft, however. Your mom might not approve if she knew. Consider that if you DO register, that supports the creation of more shareware software such as this. Columnist Karen Kenworthy tells me CMOSSAVE has been downloaded over 10,000 times from America Online alone. So far we have received 27 registrations in total. CMOSSAVE is our most frequently registered utility. We have written scores of such utilities. You can see that shareware authors don't get rich, but distributors such as AOL and Compuserve do. SITE LICENSES ************* If you wish a site license to use CMOSSAVE on multiple machines you can compute the cost using the following formula: Unit cost = $20 * sqrt( 1/n ) where n is the number of copies. Total cost = $20 * n * sqrt( 1/n ) rounded the nearest dollar if you wish. Average Incremental Copies Unit Cost Cost Total 1 $20.00 $20.00 $20.00 2 $14.14 $8.28 $28.28 3 $11.55 $6.36 $34.64 4 $10.00 $5.36 $40.00 5 $8.94 $4.72 $44.72 6 $8.16 $4.27 $48.99 7 $7.56 $3.93 $52.92 8 $7.07 $3.65 $56.57 9 $6.67 $3.43 $60.00 10 $6.32 $3.25 $63.25 15 $5.16 $2.63 $77.46 20 $4.47 $2.26 $89.44 25 $4.00 $2.02 $100.00 30 $3.65 $1.84 $109.54 40 $3.16 $1.59 $126.49 50 $2.83 $1.42 $141.42 75 $2.31 $1.16 $173.21 100 $2.00 $1.00 $200.00 200 $1.41 $0.71 $282.84 250 $1.26 $0.63 $316.23 500 $0.89 $0.45 $447.21 1000 $0.63 $0.32 $632.46 10000 $0.20 $0.10 $2,000.00 Ten thousand copies is considered an unlimited site license. Unlimited licence would entitle you to a non-exclusive irrevocable worldwide licence to use, copy and distribute CMOSSAVE within your own organization. You would not have the right to sell it to other parties. Howvever, if you were a retailer, or manufacturer, it would give you the right to install it on any machines you sell. If you were a consultant, it would give you the right to install it on any machines you service. You may modify the source code to your own requirements, but the name and address of Canadian Mind Products must not be removed from the executable code COM file. However, our name and address need not display when CMOSSAVE is run. CMOSSAVE must be used for non-military purposes only. Please mail cheque, money order to: CMOSSAVE Roedy Green Canadian Mind Products #601 - 1330 Burrard Street Vancouver, BC V6Z 2B8 Telephone (604) 685-8412 Support is available only to registered users. -30-