Date   : Mon, 01 Aug 2005 00:13:13 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: Torch Z80 ROM Images

On Sun, 2005-07-31 at 23:53 +0100, Rob wrote:
> Hmm...
> 
> Just found a pic I had taken over a year ago of the inside of the Torch 
> 68000 hard disc box I offered up recently ... specifically the co-pro board:
> 
> http://www.irrelevant.com/pics/100_0188.JPG (576Kb)
> 
> It shows an eprom with hand-written label "Torch CCCP 1.02".
> 
> The board has both the MC68000GB and a Z80BCPU adjacent to this, so I'm not 
> sure which processor the eprom is for ... (or even which processor it was 
> running when I had it working last..)

Aha, I've found the spec document for the 68K Atlas board (you've got
the earlier Neptune board - slightly slower and the memory management's
a bit cruder)

The ROM's exclusively accessed by the Z80. The Z80 issues a halt
instruction to cause execution to switch to the 68K, and the 68K issues
a reset instruction to switch control back to the Z80.

Tube interface is done primarily with an AM2950. Looks like both
processors have access to the Tube - it's just the on-board ROM that the
68K can't access.

Something else for the "to be scanned" pile... :-)

cheers

Jules