[Coco] Copying a data/binary file from disk to cassette

[Bob Devries]

Umm, sorry guys...

I made an error in the 5-byte pre-amble.
It goes $00, then two bytes comprising the length, and then two bytes 
comprising the start address.

My bad.

--
Regards, Bob Devries, Dalby, Queensland, Australia

Isaiah 50:4 The sovereign Lord has given me
the capacity to be his spokesman,
so that I know how to help the weary.

website: http://www.home.gil.com.au/~bdevasl
my blog: http://bdevries.invigorated.org/

----- Original Message ----- 
From: "Bob Devries" <devries.bob at gmail.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Friday, January 04, 2008 3:58 PM
Subject: Re: [Coco] Copying a data/binary file from disk to cassette


> Phil,
>
> The START and EXEC and addresses of a binary file on disk are actually 
> part of the disk file. Its length is also encoded there.
>
> The first byte of a BIN file on disk is always $00. After that are two 
> bytes which together form the length, and the next two bytes form the 
> START address. This comprises the 5-byte pre-amble. At the end of the 
> file, there is a 5-byte post-amble which comprises 1 byte $FF, two bytes 
> $00 and two bytes with the EXEC address.
>
> The END address can be computer from the START address plus length minus 
> 1.
>
> If you search through the maltedmedia coco list archives, you may even 
> find a program to print this info. It has been discussed before.
>
> --
> Regards, Bob Devries, Dalby, Queensland, Australia
>
> Isaiah 50:4 The sovereign Lord has given me
> the capacity to be his spokesman,
> so that I know how to help the weary.
>
> website: http://www.home.gil.com.au/~bdevasl
> my blog: http://bdevries.invigorated.org/
>
> ----- Original Message ----- 
> From: "Phil" <phil.salathe at gmail.com>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Friday, January 04, 2008 3:41 PM
> Subject: Re: [Coco] Copying a data/binary file from disk to cassette
>
>
>> Robert Gault wrote:
>>
>>>About your only option using Basic would be CSAVEM which will dump data 
>>>to cassette without making any changes. So, the disk data file will need 
>>>to be opened and stored into known memory. Let's say for example, you 
>>>POKE the data into memory starting at $3000 and continue to the end of 
>>>the file. Then you CSAVEM"name",&H3000,&H3000+length,0. To use the data, 
>>>you would CLOADM"name" and process the data stored at $3000.
>>
>> This was actually my original plan, but when I'm dealing with a .bin that 
>> I've just LOADMed into memory without qualifiers, I don't know how to 
>> ascertain the right start and execution points (which is why I was hoping 
>> to avoid the whole thing by doing a straight copy).  For instance, I have 
>> a .bin of Downland* that runs fine in emulation with a straight LOADM 
>> "DOWNLAND.BIN", but I don't know what I'd need to dump, post-LOADM, into 
>> my CSAVEM.  Is there a reliable way of finding that out?  Surely there 
>> must be something in the headers that tells LOADM where to put things, 
>> no?
>>
>> Best,
>> Phil
>>
>> *a program I actually do own on cart, though I have no idea where it went 
>> to!
>>
>> --
>> Coco mailing list
>> Coco at maltedmedia.com
>> http://five.pairlist.net/mailman/listinfo/coco
>