[BBC-Micro] Tube questions

Rob robert at irrelevant.com
Thu Jul 30 12:38:52 BST 2009

On 30/07/2009, Nick Balmer <corelki2 at hotmail.co.uk> wrote:
> Does anyone have a circuit diagram for the "TUBE"

Which side?  Logically you could argue that the tube itself is just
the straight-through cable that links the two devices...  Practically,
there's only a little more than that involved!  The BBC side of the
Tube is minimal .. it's litle more than a connection to the bus and a
couple of address lines.  This links to a custom ULA within the second
processor unit, and that is mostly a set of FIFO buffers for trickling
data between the two processors.

There's a circuit diagram and lots of useful information in the 6502
second processor service manual, on Chris's site:

You'll find the Model A&B circuit diagram in the same place.


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