Location of memory data

[midipuppies]

So, where does the memory data reside on the Emax II? By that, I mean the data that gets written when you upgrade the memory via an install disk or the adjust features code.
Is it written to EPROM? PAL? And what about this adjust features code? The information about how that decodes must be hidden in programming somewhere on board.
Could it be as simple as opening EPROM data and doing some creative editing? Copying an existing 8MB EPROM and re-writing? The memory chips are around still.
If the EPR guy has the challenge code descrambler, then someone else must as well.

Thoughts?

Jay

[rtech]

Its on a EEPROM, 93C06N. Its hard to know what/how to modify it. On the yahoo group there is a binary dump of the 8MB version, so if some one wants to update their machine it can be programmed.

 The best thing would be to able to decode what address of this  EPROM has the memory code so that we can repair one that has been modified in error or has gone bad.

The Hex of the dump is the following

3a 00 93 02 00 00 00 00 c2 01 db 01 c8 00 b8 01

bd 81 c5 a1 f0 f0 31 f1 90 41 e6 81 1a 42 13 e2

The first address being 00 and the last one is 1F. The rest of the addresses of the EEPROM according to the dump are blank with only having FF

[midipuppies]

So it is as simple as putting the 8mb EPROM image onto a machine that has been fitted with the correct memory IC's?
No install disk or adjust features codes required?
I have a few 4mb and 6mb units here. I also have a bunch of memory IC's and an EPROM burner.
Has this been done before?

Jay

[rtech]

Jay,

    Yes, no codes needed. In theory it should work, cause the only thing the the Upgrade install disk updates is the 93C06N EEPROM. I think it also holds the SCSI boot ID, because when you set it it states its saves the setting. The only thing is that I am not sure what else this EEPROM holds on the Emax II. On the Emax I this chip also holds the Filter Trim settings, but I dont have the repair manual for the Emax II so I dont know if it holds other stuff on it.
  
    If you decide to update either machine, specially the 4MB one please dump the EEPROM and put it up on the yahoo group or email it to me. I would really appreciate it, it would also help other people with fixing the common memory size error when the EEPROM gets corrupted.

Thanks

[midipuppies]

I will for sure post the data files. I just got thinking though- I bet the mono/stereo sampling info is in there as well.
The one 4 meg unit I will use as a test subject is a mono machine. I am assuming that the 8 meg image on the Yahoo group is for a stereo machine. As far as I know, if you try to tell a mono Emax II to be a stereo one without adding the correct hardware, sampling will be completely disabled.
I will keep you posted!

Jay

[rtech]

My 4MB is a stereo version, I will try to dump the EEPROM to compare it with yours.