Date   : Thu, 15 Feb 1996 12:23:51 +0100
From   : Robert Schmidt <robert@...>
Subject: Re: Tape decoding status

>I actually don't know if it works as my beeb is in Denmark. I am in Germany
>at the moment, but are going home the end of this month. I will continue
>the work when i get back. I wrote the player on basis on the info from
>the mails i got. I still have to add some format-specifikations blocksize
>CRCs... if i want to read standart formats. I will probably have to find my 
>Advanced user guide when i get home to find this information ( If some of
>you boys and girls have the info, you should not hesitate to mail it to me )

I've been reading that particular section of the AUG often enough, so I know
this by heart:  (well, I might be wrong, so check it up when you get home)

0 = 1 cycle of 1200 Hz
1 = 2 cycles of 2400 Hz

All bytes have one start bit (0) and one stop bit (1) - no parity.

5 seconds synch tone (2400 Hz) - possibly interrupted early on by a single
&AA byte (an early synch bug fix)
10 REM Start of block
   0x2A - synch byte
   Filename - 1 to 10 bytes
   0x00 - to terminate the filename
   Load address, 4 bytes, low byte first
   Exec address, 4 bytes, low byte first
   Block number, 1 byte
   Block length, 2 bytes, low byte first (is it ever > 256?)
   Block flag, 1 byte - bit 7==1 means last block
   16-bit header CRC, high byte first, excluding 0x2A (algorithm in AUG)
   Data, number of bytes given by block length
   16-bit data CRC, high byte first
   A second or so of synch tone, then...
20 GOTO 10


Have fun.


--
Robert Schmidt - robert@...         - http://www.idt.unit.no/~robert
	
	Maintainer of "The BBC lives!" page:  
	http://www.idt.unit.no/~robert/bbc/bbc.html