[Techtoolslist] Looking for Fluke 9010a U62 (82S123) PROM Image

Grant Goodes grant.goodes at gmail.com
Wed Aug 9 10:30:08 EDT 2017


   A list-member kindly provided me with the image-file for U62, and I
   have provided that to John, along with a small PDF describing the logic
   of the bank-select circuit, and that has now been uploaded to the FTP
   site under the Fluke/9010 Series/9010 ROMs directory.  I hope that this
   will help out others who had this problem.
   Turns out that, yes, the 82S123 in my friend's board had failed, and
   the contents were reading incorrectly.  Burned a new PROM, but that
   didn't fix the non-booting issue, so there's something else wrong.  At
   this point, we are suspecting the Watchdog circuit, and will debug that
   next.
   grant..

   On 2017-08-03 4:49 PM, Grant Goodes wrote:

   Hi list-members,
   A friend has a Fluke 9010a that won't boot.  After finally tracking
   down a z80 pod, we used my functioning 9010a to do some debugging
   (using information in the Service Manual), and figured out that the ROM
   at 0-3FFF was colliding with the ROM at 4000-7FFF: When you try to read
   address 4000, you get the contents of address 0.  Schematic spelunking
   implicates the Memory Page Selector chip U62 which is a 82S123 PROM.
   We could just replace the PROM, but I've not been able to find the
   image-file for this one.  Does anyone have an image-file for U62, or
   even better a spare U62?  A local guy in Ottawa can burn this PROM for
   us, but then we'd need the image!
   We will of course do some more debugging: In particular, we need to
   trace the ROM chip-select signals back through to the z80 with the
   9010a in Read-mode/loop, but ran out of time in our late-night
   debugging session last night.
   Thanks for any help: Would be great to get my friend setup with a
   working 9010a!
   grant..


More information about the Techtoolslist mailing list