Emax

You are exactly right Ted, the expansion board has 4 PALs on it plus some 74HCxxx chips on it, it is also a 4 layer board, so the amount of work it would take to duplicate it is just not worth it.
As for "stacking" chips on the motherboard's 18 pin sockets, not a hope in hell of that working (sorry).
The only way to upgrade the Emax2, is to have the original upgrade board, as long as you have that, you can upgrade it to anything you want.

Dave


--- In emax@yahoogroups.com, Ted Summers <djtbs1@...> wrote:
>
> My understanding is that the RAM expansion board has PALs that go with it.
> Getting the PAL binaries for the SCSI update wasn't easy for Rob at Emulator
> Archive.
> Even if you duplicated the PCB, you would have to be able to make the PALs
> that allow the access to the extra memory.
> You would need the original PAL binaries for that.....
> 
> Otherwise the Emax wouldn't be able to address the additional memory....
> even if it was physically installed.
> 
> Someone correct me if I am wrong in my understanding of what was discussed
> previous on the thread.
> 
> Regards,
> Ted
> 
> 
> 
>