Date   : Wed, 15 Mar 2006 14:08:50 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: 1MHZ SCSI/ATA board

Phil Blundell wrote:
> On Wed, 2006-03-15 at 11:49 +0000, Jules Richardson wrote:
>> Are the crystals on your board(s) all 4MHz too then?
> 
> The crystal on the one I was looking at yesterday is marked 8MHz.  I
> guess it's divided by two for the CPU, though, which would indeed give
> 4MHz.  If that's the case, I suppose your "12MHz" unit is actually
> running at 6MHz.

Yes, it is - just checked :)

Any idea what the Intel chip next to the CPU is? I presume it's some sort of 
clock generator, but I seem to recall not being able to find a datasheet when 
I was looking a few months back. 18 pin DIL, marked D82284 and 14340081.

Oh, and presumably you have an empty 40 pin socket next to the TUBE ULA? 
Memory says that's a 80287 copro socket (I think the pinouts made sense when 
I'd started to draw out schematics a while back).

My board's an issue D - I'm surprised they ever built enough to get beyond 
issue A!

Hmmm, I'm off to the States again on Friday for a while - when I get back I'll 
give the chap a prod who used to own this board in Cambridge though, as he 
thought he might just have a few related bits of design docs in his loft.

cheers

Jules