[Coco] tape format and .cas file problems

[Roger Taylor]

At 08:38 AM 11/19/2008, you wrote:

>So, could you come up with a client/server system where you CLOADM a
>small routine at 1MHz from the host PC which auto-executes, patches
>BASIC's cassette routine (assuming CoCo 3 or RAM-able 64K CoCo) for the
>faster protocol, and optionally switches the computer to 2MHz?  Then
>subsequent loads would zip.


Probably overkill.  Also, CLOADM only supports one start address as 
far as I recall.  This means the entire ML program has to be 
contiguous, unlike the multi-record LOADM format which can jump all 
around RAM doing what it wants.

I remember back in the 80's seeing Rainbow magazine ads selling CoCo 
tricks like "Auto executing tape programs" but I could be wrong.  I'd 
like to know how a lowly 16k or even 4k CoCo 1 could do this just by 
typing CLOADM.  I don't see anything in the tape format that allows 
for such a trick.


NOW, getting to this .CAS file subject that's been talked about 
already... there seems to be a lot of .cas files available that are BAD.

Here's what I have noticed in a lot of the bad .cas files.

First leader is far too short or inverted ($AA's)
Silence gap too short, or missing, after the 1st (filename) block
Second leader is far too short or inverted ($AA's)

If a file is already goofed up like this, even if you hand-edited the 
HEX file to fix it (like I've done with some), you will still 
probably have bad data blocks in the rest of the file.  That is, the 
checksum at the end of the blocks are probably wrong.

I'm looking now for the .cas specs.  Anybody?

-- 
Roger Taylor

http://www.wordofthedayonline.com