Date   : Wed, 27 Aug 2008 22:46:28 +0100
From   : jumbos.bazzar@... (Mark Haysman)
Subject: FRAM....

Hi Folks.

I've been playing with some FRAM, namely the Ramtron FM1808. I've got a B 
which runs fine with the 62256 SWR mod in socket 15, however, it plays up 
when I pop a FRAM in there.

If I write a ROM to it and reset the machine, it crashes. I initially 
thought that it's the way the FRAM latches addresses on the /CE pin maybe 
that's causing it not to write correctly, but it appears not. I've wired a 
switch to /OE so I can recover the machine when it hangs.

I can write data into it with *SRWRITE or my own loader software, and read 
the data back out and it's identical. I can do an SWR RAM test on it, and it 
passes perfectly. I've even tried storing basic & MC programs in it, and 
they load back perfectly and identical, but if I write a ROM in it, nothing, 
just a crash with the cursor in the top left corner. This is with ROMs that 
run perfectly if I use a regular 62256 in the same socket. I've even 
confirmed that it's not getting corrupted by resets or power-on, as any data 
I write into it is still there perfectly after several power on/off 
sequences.

Any ideas?

Thx, Mark.