Date   : Sun, 27 Jun 2004 00:37:57 +0000
From   : "W.Scholten" <whs@...>
Subject: bbcim/bbctape

L.S.


> Might I request a re-appearance of BBCIM, as I've found it indispensable
> for opening up disc images and checking CRCs.

Aha, I'm not the only one paranoid about file transfer ;)

>  Possibly the file
> whs_tape_utilities_10_5_2001.zip also.  If not, I'd be happy to host them
> both instead.

Anyone can use/update/host those files. All files are under a BSD-like
licence or public domain, so please do. I should finally release my far
better bbctape (which uses integration over 1200/2400Hz waves). I've got
a dual BBC/Atom version which I should clean up first.

Btw, has anyone else noticed that the Atom uses half-1 bits at the end
of a byte? This gives an awful mess decoding, and worse, means it's
impossible to write 0=1200Hz, 1=2x 2400Hz for a bitstream. I wanted to
see if this worked on a BBC micro as well, so I wrote a bitstream using
extra half-1 bits (about 18 samples at 44100 Hz) at the end of each byte
(note that any number of 1-bits after a stop bit is allowed and the old
published bbctape already allows this IIRC). The BBC loaded the program
sent this way without problem... Hmm, I hope there aren't any custom
produced bitstreams in games that do this, or the standard bitstream
format is not adequate (probably not possible to make such tapes via the
cassette output port on the BBC or is it?).

> Thanks for noticing my last patches, in 0.103 :-)

I think I saw it earlier, and IIRC I did get those bug fixes from that
(probably would have seen it during the rewrite but not sure, they were
really stupid errors, the type that lasts for years without noticing ;-)
). One change in the patch I saw was not an error but a change of
meaning, but I decided to do it your way anyway. I did have some
problems using 0.103 and the whole code should be changed to use
opendir/readdir type functions instead of the trying to do it as
efficiently as possible (cat/extract in a single function for example
which gives an ugly unmaintainable mess), but I can't see myself doing
it soon yet.

If there are people willing to help debug/test/check or write code I'm
more interested in updating/fixing. Sometimes it feels to me, as Mark
Usher noted about his efforts on the BBC doc website, "What am I doing
the effort for if there's very little help or feedback".


Regards,

Wouter
--
BBC/Atom/magazine scans:
     http://8-bit.summerfield-technology.co.uk/