Reviving a bricked Adaptec 1542CP (BIOS flash issue) \ VOGONS

Reviving a bricked Adaptec 1542CP (BIOS flash issue)

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First post, by mpe

Posted on 2021-03-09, 11:29

mpe Offline

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I attempted to upgrade BIOS and microcode on my Adaptec 1542CP and it did not end well. I attempted to flash this one to this card:

I was too lazy to reach for new chips and attempted to update original EEPROM chips 🙁 That was a stupid decision I know.

The new update did not work so I was about to flash it back.

At least I saved the original content. However, I can't flash them back for some reason. It fails to verify:

1% minipro -p AT27C256R@DIP28 -w adaptec-1542CP-rom2.rom
2Found TL866II+ 04.2.124 (0x27c)
3Warning: Firmware is newer than expected.
4  Expected  04.2.122 (0x27a)
5  Found     04.2.124 (0x27c)
6
7VPP=13V, VDD=6.5V, VCC=5V, Pulse=100us
8Chip ID OK: 0x1E8C
9Writing  Code...   0%
10Verification failed at address 0x0080: File=0x16, Device=0x00

With--skip_verify it seems to be writing fine:

1 % minipro -p AT27C256R@DIP28 -w adaptec-1542CP-rom2.rom --skip_verify
2Found TL866II+ 04.2.124 (0x27c)
3Warning: Firmware is newer than expected.
4  Expected  04.2.122 (0x27a)
5  Found     04.2.124 (0x27c)
6
7VPP=13V, VDD=6.5V, VCC=5V, Pulse=100us
8Chip ID OK: 0x1E8C
9Writing Code...  3.94Sec  OK

However, the Adapter BIOS doesn't show at boot when the card is in the PC. And also the checksum of .rom file read back doesn't match the originals I saved

If I use new chips I can flash it without --skip_verify. However, the BIOS doesn't work either.

Not sure if could be because I am using 512kBit SST27SF512 chips - originals were 256kBit AT27C256R).

Anyone has any idea how to debrick my controller? Or have a known working copy of BIOS files for this card?

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Reply 1 of 6, by Doornkaat

Posted on 2021-03-09, 12:06

Doornkaat Offline

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When I'm using replacement EEPROMS larger than the original I edit the rom file to double the size and fill the empty space with a copy of the rom. Usually this works if the EEPROM is electrically compatible.

Reply 2 of 6, by maxtherabbit

Posted on 2021-03-09, 14:31

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You are telling the minipro to program a AT27C256R which is an OTP EPROM i.e. it cannot be erased after it is initially programmed.
OTP = "one time programmable" = you never should have tried reprogramming it to begin with. All you did was corrupt the code that was already on there.

You need to throw the 27C256Rs away, and use the flash - remember to change the command line to reflect the IC you are actually using so the programmer will know it is flash memory and do a proper erase before write. Might as well use the newer binary images too, the only reason they didn't work initially was because you were trying to write them to an unerased EPROM. Also duplicate them like the previous poster mentioned

Reply 3 of 6, by mpe

Posted on 2021-03-09, 16:09

mpe Offline

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Oh. Silly me!

I had no idea these can be progammed only once. I was assuming these are ordinary EEPROMs.

What is the best way how to pad the ROM to fit larger chip? Just concatenate 32768 empty bytes to the end of the file? Like this?

1 
2dd if=/dev/zero of=zerobytes.rom count=32768 bs=1
3cat zerobytes.rom >>  adaptec-1542CP-rom2.rom

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Reply 4 of 6, by maxtherabbit

Posted on 2021-03-09, 16:12

maxtherabbit Offline

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mpe wrote on 2021-03-09, 16:09:

Oh. Silly me!

I had no idea these can be progammed only once. I was assuming these are ordinary EEPROMs.

What is the best way how to pad the ROM to fit larger chip? Just concatenate 32768 empty bytes to the end of the file?

no, duplicate the existing image

on windows it would be:

1copy /b adaptec-1542CP-rom2.rom+adaptec-1542CP-rom2.rom outputfilename.bin

Reply 5 of 6, by mpe

Posted on 2021-03-09, 19:35

mpe Offline

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Got it working (with 512kBit EEPROMS and duplicated contents) thanks! Lesson learned. At least I am glad I saved the original ROMs.

Anyway, if anyone has a BIOS version newer than 1.02 (that supports 4GB disks, please share it)

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Reply 6 of 6, by weedeewee

Posted on 2021-03-09, 19:56

weedeewee Offline

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did you try the 2.11 one that can be found on vogons in the 'new' eeproms ?

It's not quite clear to me whether or not you did.

edit: Nevermind ... from the bios files 'AHA-1540CF/1542CF BIOS not intended to run on this AHA-1540CP/1542CP!'

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