Nice work! On Sat, 23 Apr 2022 at 23:33, Andrew Welburn <andy@andysarcade.net> wrote:
hi all.
There's a 32-byte soldered-in I2C serial EEPROM (type X2444) that contains crucial hardware setup information use in the Fluke 9100 series systems. The values in this eeprom hold information pertaining to some calibrations as well as all basic I/O hardware. This information can all be set/changed with the use of floppy service disks in a working system.
If you happen to set the wrong floppy drive type in this menu, you can lock yourself out of being able to adjust anything, as well has having a non-working floppy drive.
You can re-program the chip in-circuit (in theory, but i didn't try it) or you can de-solder it, and dump the contents/reprogram it. The 32 bytes might be a little cryptic, but with trial an error i have found out the following address map. It is not exhaustive, there are likely more things stored in here relating to IO mod or pod or probe calibrations accessed in the setup/calibration menus from a regular boot cycle, but for now, this is what i have discovered:
offset Purpose Notes ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 00 to 03 Serial # Little Endian 04 System/disk type Note1 05 to 08 Probe offset calibration values 0A Disk err reporting 00=OFF 0A=ON 0C,0D unknown do not change 0F RAM size Note2 11 Network Node 00 to F4 is valid 15 Floppy type Note3 18 to 19 IEEE option YES=04D7 NO=14D7 1A to 1C site # Little Endian 1E to 1F checksum Note4
Note1 = 42=9100/Miniscribe 76=9100/scsi512 66=9100+scsi256 00=9105/9050
Note2 = 18=1.5mb 20=2mb 30=3mb 40=4mb 80=8mb F0=15mb
Note3 = 00=Gotek 01=Canon 03=Sony 04=Mitsumi 05=Teac 06=CanonHD
Note4 = BSD Checksum, but barrel-rotated right 10 bits then inverted see: http://www.andysarcade.net/personal/tech/fluke9100/andysum.zip
Big props to TheMogMinor/MooglyGuy for figuring out the checksum, as well as writing the utility and providing source code!
Now you can create a binary yourself, generate/apply a valid checksum and write this to the ROM and get yourself back in business.
enjoy.
-- Andrew Welburn andys-arcade _______________________________________________ Techtoolslist mailing list Techtoolslist@flippers.com https://pairlist7.pair.net/mailman/listinfo/techtoolslist FTP site is: ftp://ttl.arcadetech.org/TTL/Test_Equipment Archive site: http://seven.pairlist.net/pipermail/techtoolslist/
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