Date   : Sun, 05 Oct 1997 22:07:17 +0100 (BST)
From   : Mark Cooke <mpc@...>
Subject: Tube Info

Hi all,


I've been playing around with my emulator, and specifically with a Tube
emulation.

As a note for anyone else, it appears that the 4K rom is mapped into the
address space when the board is reset, and it is unmapped after the first
access to the interface ASIC.

It also appears that any address writes are stored in the RAM, even if the
ROM is still mapped in.

There's some 'weird stuff' to do with DRAM refresh I've not spent time
looking at yet either. More info later as I discover it.

Regards,

Mark

Mark Cooke                  The views expressed above are mine and are not
Systems Programmer          necessarily representative of university policy
University Of Birmingham    URL: http://www.sr.bham.ac.uk/~mpc/