Well, it looks as though we’ve done it!! Having produced the last issue
somewhat late, it looks as though we have got back on schedule with this one.
Mind you, I’d better not make too much of it, or some law or other will
prevail, and it will be six months to the next issue!
Some of you who have subscriptions will probably be receiving this issue in
the same post as the previous one. Sorry if this comes as rather a shock,
but as I doubt that we will have got all of the last issue in the post by the
time we get this one back from the printers, it seems silly to double up on
postage costs. If you don’t want to read two issues at once, then put this
one away for three or four weeks! Bye, bye for a while.......
Some time later
Hello there. And what has been happening since you received the last issue of
this wonderful magazine? It seems like only yesterday! Well, for a start, I
am afraid that I have to report that despite further letters to Lucas/Nascom
and to IO Research we have still NOT heard from them about the I/O mapping of
their 80-BUS/Nasbus boards. Now, the questions asked were not too tasking, and
went along the lines of:
a) What boards have you/do you/will you produce that occupy Z80 I/0 ports?
bv) What are the recommended standard addresses for these boards, what
alternatives are there, and how are these options achieved
ec) Are NASIO and DBDR provided (necessary for Nascoms)?
a) Can the boards be used with Nascom 1/2/3, Gemini GM811 & GM813?
e) Are there any special restrictions that we should know about?
Answering this lot should take about 10 minutes per board, and nobody makes
that many boards that this should produce a serious problem. And why an I
making all this fuss? Well, there are now about 25 80-BUS compatible boards
available, all fighting for 256 ports. Not a serious problem yet? Well,
unfortunately there have already been clashes. Gemini brought out the GM812
IVC some time before the Lucas/Nascom AVC. And yet the IVC uses ports Bi, B2
and B3, and guess what? – the AVC uses ports BO, B1 and B2. Yes, the AVC and
IVC can both be located elsewhere if necessary, but the standard software
‘support for both of them assumes these port addresses. And why should someone
who may well want both boards be hampered by this restriction? Another
example of this clashing is between the Climax colour board and another board
being produced by a new manufacturer. The Climax uses CO-DO, and the first
release of the new board (which I can say no more about – tease, tease!) uses
CO-CF. It looks as though they’ll have to change it before going into full
production. And we all know that IO Research have already shown a prototype
of their Pallette board, and have announced two other forthcoming products as
well. What ports do these use, and what will they clash with? This is my
reason for the third part of question (a) above. TI am not expecting all
existing and potential manufacturers to send me full details of their yet-to-be-released
products, but it would be nice if they sent a note saying "New
board, available approx 3 months, uses ports 40-9F"! In order not to prolong
the agony, awaiting the reply of obviously disinterested parties, you will
find in this issue a VERY brief summary of current port usage. If you know of
any boards that I have missed, any mistakes that I have made, and any boards
that are under development (no need to say what), then PLEASE drop me a note.
Well, that’s all there is space for. Material and ads. for the next issue by
July 30th please. And until then, TTFN.