>>The size of the FLASH was halved. >> >>Same strategy used by Adaptec to prevent "diversion" of their 29xx SCSI >>controllers to the Mac. >> >Could well be - the other theory I've heard is that half the rom is >locked but can be unlocked by applying a small voltage to one of the >pins. Confusion reigns as the flasher will still extract a 128k pc rom >from the alleged 64k chip and apparently write it back to the chip.
Most of the FLASH ROMs have a locked portion (usually 1/4 of the total capacity) and an unlocked portion. The intended purpose of the locked portion is for a boot ROM. The intended purpose of the unlocked portion is for a small RAM, also used during booting. But, such a ROM doesn not have to be used in locked/unlocked mode. The secret behind most of these cards is the FLASH utility inspects the ROM "signature" before it effects a FLASH. Reducing the total capacity of the ROM to one-half is an additional measure to prevent diversion. So, you will find these techniques in use, although not all of them within the same product: 1) different ROM "signatures", but same ROM capacity, for different end-user products, 2) one-half ROM capacity for PC; full capacity for Mac, 3) both (1) and (2), and 4) FLASH incorporated into the LSI chip itself, with a different chip part number for the PC as for the Mac. In any case, the Mac FLASH utility must have a FLASH ROM of the right "signature" and the right capacity in order for the FLASH to be successful. -- G-List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- We have Apple Refurbished Monitors in stock! | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> G-List list info: <http://lowendmac.com/lists/g-list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/g-list%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
