Date   : Mon, 22 Jun 2009 19:11:19 +0100
From   : jgh@... (Jonathan Graham Harston)
Subject: mystery ROMs

Phil Blundell wrote:
> On the subject of View, how does the versioning system work for that?  I
> seem to have, among others. chips labelled as being "View C21", "View
> A21" and "View 21K" but I'm not quite sure what the letters signify.
 
It's a puzzle. At http://mdfs.net/roms/TextEd I've got
 
ViewA140  VIEW   1.40 (C)1982 Protechnic
ViewA210  VIEW   2.10 (C)1982 Protechnic
ViewB210  VIEW   2.10 (C)1982 Protechnic
ViewD210  VIEW   2.10 (C)1982 Protechnic
ViewA300  VIEW   3.00 (C)1982 Acornsoft
ViewB300  VIEW   4.00 (C)1982 Acornsoft
ViewJ300  VIEW   4.00 (C)JGH & Acornsoft
 
I used the 'J' prefix to indicate my patched version. View seemed
to get patched and rebuilt in many variations. As it only takes up
about 10K - 11K of ROM, there's plenty of space for extension.
 
View A2.10 has a well-publicised bug which causes it to fail to
scroll the screen correctly when using shadow RAM.
 
-- 
J.G.Harston - jgh@...                - mdfs.net/User/JGH
BBC BASIC for Windows and Internationalisation
  See http://mdfs.net/Software/BBCBasic/Windows/ProgTips