Date   : Mon, 25 Sep 2000 20:13:10 +0100
From   : Philip Peake <philipp@...>
Subject: 1770 disc interface

Hi all,

Does anyone have a circuit diagram for the 1770 disc interface? Has anyone tried
to build one (for the model B)?

Can one do a straight swap WD1770PH for WD1772PH? I believe Acorn used the 1772
in a Master Compact because it works better with 3.5" drives. Also, does the ADFS
rom require the DFS rom to be present to work? And can the rom images at
http://www.nvg.ntnu.no/bbc/roms/ be blown to PROM -- any tips?

As well as the 1770 module, the Acorn installation guide specifies that '2 off
7438 Integrated Circuits' are required for the 14 pin DIL sockets at IC79 and
IC80. Is the Texas Instruments SN7438N suitable for this?

Thanks

Phil Peake