Hammond XB-2 ROMs?

I have two secondhand Hammond XB-2 Hammond clones (c’mon, even if it had made by Hammond proper before being bought by Suzuki, a solid-state, digital audio synthesis keyboard is still a clone) which both appear to have bit rot in their firmware EPROMs, apparently a common problem with these keyboards.

I’d be extremely grateful for pointers to where I could get new EPROMs or download images to burn myself, or to another XB-2 owner willing to read out their EPROMs to assist. Heck, I’ll burn you another copy so you have a fresher set when yours bit-rot.

They’re IC16 and IC17 and they’re 27256es.

9 Responses to “Hammond XB-2 ROMs?”

  1. Joe Koberg says:

    If you have two of the units maybe you can read and compare the two ROMs.

    EPROM bit rot turns 0′s into 1′s, so everywhere one ROM has a 1 but the other a 0, keep the 1.

    Joe

  2. Joe Koberg says:

    Err, the other way around. Keep the 0′s….

  3. Keith Neufeld says:

    Joe, unfortunately one of my keyboards has the original ROMs and the other has the v2 upgrade, so I can’t compare.

    I’m still thinking about taking the ROMs out, reading them slowly lots of times, and “merging” the different readings that I get from each chip, on the theory that perhaps a rotting bit won’t have fully blanked yet and will still sometimes give me a 0.

  4. Joe Koberg says:

    You may also try reading with different voltage levels supplied to the chip; and even perhaps with the chip cold. These are just shots in the dark. It’s my understanding that once the cell has flipped back (lost its stored charge), it’s flipped for good.

  5. Merlin Skinner says:

    I have seen EPROMs with “flaky” bits. Presumably the charge has decayed to a point near the threshold of the sense circuitry. I can’t think of any mechanism that would make the bit latch in the flipped state – it would just more more and more likely to be read incorrectly. Light falling on the chip can also cause this.

    Joe Koberg’s idea of varying the supply voltage is likely to be a good strategy, as the EPROMS I had were sensitive to this. At least some programmers (e.g. DataIO) allow you to select the voltage (4.5/5.0/5.5V, perhaps). Heating as well as cooling (hairdryer/freezer) is very likely to affect this threshold as well.

    Good luck!

  6. Laci Biro says:

    I have a similar problem: the ROMs in my old XB-2 are defective and I’m unable to find V2 images in order to burn a new set.

  7. Gioacchino Venuti says:

    She found then has the v 2 or EEPROM files for ‘ Hammond XB- 2 ?
    Gio.

  8. XB2 says:

    I have a XB-2 with V2 roms.
    It does not work but maybe the ROMS are Ok,

  9. Can you send me a copy of the Rom in file .hex or .bin or if you can send me the two chip roms at this address “Gioacchino Venuti, via abruzzi 2/D, Grottaglie (TA), italy”. If you decide to sand me the two chip roms, tell me how much is it.
    Gio

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