Date   : Wed, 08 Oct 2003 17:30:19 +0100
From   : David Devenport <dave@...>
Subject: Re: XFER v4 problem

I don't know if this helps, but when I wrote my emulator I linked my pc 
to BBC via a serial cable,
the BBC could talk (transmit) to the PC fine, but WOULD NOT under any 
circumstances receive anything
transmitted from the PC. I put this down to the different voltage levels 
from RS232->RS423.

Cheers

Dave

PS I still have the BBC source code and a PC executable that I used to 
transfer BBC->PC, if they're any
use to anyone (slow as hell but it worked) :)




Mike Tomlinson wrote:

>In article <002701c38d29$7993a2c0$94342fca@...>, Bob Devries
><bdevries@...> writes
>
>  
>
>>C.Pascal    8000   D9CD Locked CRC= E388
>>
>>Is there something wrong with this?
>>    
>>
>
>The load and exec addresses are unusual - &8000 is the start of Sideways
>ROM space, and &D9CD is the warm start entry point on the BBC B OS 1.20.
>So if one tried to execute C.Pascal (*RUN C.Pascal) it would load the
>file over the currently selected ROM (which does nothing) then reset the
>machine.  
>
>This has two possible purposes:  to indicate that the file is not
>executable machine code, or it could mean the file is a ROM image (if it
>is exactly 8192 or 16384 bytes, it probably is a ROM.  You can tell by
>looking at the first few bytes with *DUMP.)
>
>I can't see the load and exec addresses affecting XFer - it simply opens
>files from disc and squirts the contents down the serial port.
>
>"Locked" simply means the file has been made read-only with *ACCESS
><file> L.
>
>  
>