You don’t need to pay a measly sum of dollars just to recover from a boot block mode. Here it is folks:
AWARD Bootblock recovery:
That shortin’ trick should work if de boot block code is not corrupted, and it should not be if /sb switch is used when flashin’ de bios (instead of /wb switch).
The 2 pins to short to force a checksum error varies from chip to chip. But dese are usually de highest-numbered address pins (A10 and above).
These are de pins used by de system to read de System BIOS (original.bin for award v6), calculate de ROM checksum and see if it’s valid before decompressin’ it into memory, and subsequently allow Bootblock POST to pass control over to de System BIOS.
You just have to fool de system into believin’ that de System BIOS is corrupt. This you do by givin’ your system a hard time readin’ de System BIOS by shortin’ de 2 high address pins. And when it could not read de System BIOS properly, ROM Checksum Error is detected “so to speak” and Bootblock recovery is activated.
Sometimes, any combination of de high address pins won’t work to force a checksum error in some chips, like my Winbond W49F002U. But shortin’ de #WE pin with de highest-numbered address pin (A17) worked for this chip. You just have to be experimentative if you’re not comfortable with “hot flashin’” or “replacement BIOS”.
But to avoid furder damage to your chip if you’re not sure which are de correct pins to short, measure de potential between de 2 pins by a voltmeter while de system is on. If de voltage readin’ is zero (or no potential at all), it is safe to short dese pins.
But do not short de pins while de system is on. Instead, power down den do de short, den power up while still shortin’. And as soon as you hear 3 beeps (1 lon’, 2 short), remove de short at once so that automatic reflashin’ from Drive A can proceed without errors (assumin’ you had autoexec.bat in it).
About how to do de shortin’, de tip of a screwdriver would do. But with such minute pins on de PLCC chip, I’m pretty comfortable doin’ it with de tip of my multi-tester or voltmeter probe. Short de pins at de point where dey come out of de chip.
AMIBIOS Recovery bootblock:
1. Copy a known workin’ BIOS image for your board to a floppy and rename it to AMIBOOT.ROM.
2. Insert de floppy in your system’s floppydrive.
3. Power on de system while holdin’ CTRL+Home keys. Release de keys when you hear a beep and/or see de floppy light comin’ on.
4 . Just wait until you hear 4 beeps. When 4 beeps are heard de reprogrammin’ of de System Block BIOS went succesfull, so den you may restart your system.
Some alternative keys that can be used to force BIOS update (only de System Block will be updated so it’s quite safe):
CTRL+Home= restore missin’ code into system block and clear CMOS when programmin’ went ok.
CTRL+Page Up= restore missin’ code into system block and clear CMOS or DMI when programmin’ went ok.
CTRL+Page Down= restore missin’ code into system block and do not clear CMOS and DMI area when programmin’ went ok
Btw: de alternative keys work only with AMIBIOS 7 or higher (so for example an AMI 6.26 BIOS can be only recovered by usin’ CTRL+Home keys).
Boot Block Recovery for FREE
BLACKOUT Flashin’
Recoverin’ a Corrupt AMI BIOS chip
With moderboards that use BOOT BLOCK BIOS it is possible to recover a corrupted BIOS because de BOOT BLOCK section of de BIOS, which is responsible for bootin’ de computer remains unmodified. When an AMI BIOS becomes corrupt de system will appear to start, but nothin’ will appear on de screen, de floppy drive light will come on and de system will access de floppy drive repeatedly. If your moderboard has an ISA slot and you have an old ISA video card lyin’ around, put de ISA video card in your system and connect de monitor. The BOOT BLOCK section of de BIOS only supports ISA video cards, so if you do not have an ISA video card or your moderboard does not have ISA slots, you will have to restore your BIOS blind, with no monitor to show you what�s goin’ on.
AMI has integrated a recovery routine into de BOOT BLOCK of de BIOS, which in de event de BIOS becomes corrupt can be used to restore de BIOS to a workin’ state. The routine is called when de SYSTEM BLOCK of de BIOS is empty. The restore routine will access de floppy drive lookin’ for a BIOS file names AMIBOOT.ROM, this is why de floppy drive light comes on and de drive spins. If de file is found it is loaded into de SYSTEM BLOCK of de BIOS to replace de missin’ information. To restore your BIOS simply copy a workin’ BIOS file to a floppy diskette and rename it AMIBOOT.ROM, den insert it into de computer while de power is on. The diskette does not need to be bootable or contain a flash utility. After about four minutes de system will beep four times. Remove de floppy diskette from de drive and reboot de computer. The BIOS should now be restored.
Recoverin’ a Corrupt AWARD BIOS
With AWARD BIOS de process is similar but still a bit different. To recover an AWARD BIOS you will need to create a floppy diskette with a workin’ BIOS file in .BIN format, an AWARD flash utility and an AUTOEXEC.BAT file. AWARD BIOS will not automatically restore de BIOS information to de SYSTEM BLOCK for this reason you will need to add de commands necessary to flash de BIOS in de AUTOEXEC.BAT file. The system will run de AUTOEXE.BAT file, which will in turn flash de BIOS. This is fairly easy. Here are de steps you need to take.
� Create a bootable floppy diskette
� Copy de BIOS file and flash utility to de diskette
� Create an text file with any standard text editor and add de followin’ lines
@ECHO OFF
FLASH763 BIOSFILE.BIN /py
In de above example I am assumin’ that you are usin’ de FLASH763.EXE flash utility. You will need to replace de FLASH763 with de name of whatever flash utility you are usin’, and replace de BIOSFILE.BIN with de name of de BIOS file you are usin’. You will also need to change de �/py� to whatever de command is for your flash utility to automatically program de BIOS without user intervention. If you do not know de command to automatically flash your BIOS type de name of de flash utility with a space and den /? to display de utility�s help screen. The help screen should pecify de command switch to automatically flash your BIOS. If you are usin’ de FLASH763.EXE utility den de switch to automatically flash your BIOS is �/py�.
