That said, there may be multiple blocks (or sectors) in the flash device, one of which is used for ESCD. I have several 1-MBit EEPROM chips, all of which function the same, as far as I can tell, with the exception of 12 V or 5 V for programming.
The Intel P28F001, for example, mentions: -One 8 KB Boot Block w/Lock Out -Two 4 KB Parameter Blocks -One 112 KB Main Block I beleive the ESCD is in either the 8 KB or the 4 KB block.
The BIOS does not have an option to reset the configuration data.
The only means I know how to do this is to physically swap the order of my PCI cards each time I want to boot.
Depending on the eeprom type, that might be a huge pain in the cheeks and you may be thwarted by the motherboard's control over certain voltages that have to be present to erase.
(Vpp) If you have access to a flash bios upgrade tool for your motherboard, there may be some disassembly work and some routines to leverage in there.
Alternately, is there a DOS program which will clear out the bootblocks?
You can use this tool that I wrote: poke around in a lot of HW devices on your 486 machine. It has the ability to display and edit both CMOS banks.
The RTC clear jumper might only be clearing the primary bank of storage.Does anyone know a hack which I can do to achieve this?Not even the RTC reset jumper clears the PCI configuration data.I would think that one of the 4k blocks is where the ESCD data resides.I have to clear out a few more cobwebs to remember the specifics, but I believe the eeprom is mapped at the top of memory (at 4Gb) and then mirrored at ffff:0000 for BIOS services.So presumably I could freshly flash my BIOS to the EEPROM and leave the program jumper off, but that is still not what I am after.