View Full Version : Flash ROMS unlock boot sector

July 31st, 2009, 05:36 AM
I just bought 20x PMC pm29F002T-12PC Flash ROMS, unfortunately they all have the boot sector locked which means it can't be re-flashed.

According to the datasheet there is a special code sequence that unlocks these - it says to call "the manufacturer". Unfortunately the manufacturer is no longer around. Does anyone know the unlock sequence - I've made my own programmer so can do any bit banging required.

While not really "vintage" I was hoping to use these parts with suitable pin swapping in a few of my vintage and homebrew machines.

Sorry if this is the wrong place to ask!



July 31st, 2009, 06:18 AM
It's in datasheet, here:

July 31st, 2009, 06:32 AM
Sorry its not in the datasheet. That's the datasheet I'm working from.

It's got information on how to lock, how to detect lock but for *unlock* all it has is: "1. Please call manufacturer for the command code to
disable the boot block lockout."

I should mention that it *could* add a 12V reset to program but that would reduce the usefulness of the devices as I'd really like to be able to reprogram them in the destination machines if possible.



July 31st, 2009, 09:44 AM
Did you try with Boot Block Lockout command with last command byte of 20h?

August 1st, 2009, 11:28 AM
Hi! I found a PMC PT29F002T in my stash of old Flash memories. I put it in the Easy Pro90B programmer and it erased and blank checked just fine.

What sort of programmer are you using? A quick search on Google indicates there are PMC PT29F002T erasers available for Willem style programmers.

Thanks and have a nice day!

Andrew Lynch