Re: XIEEE

g.j.p.a.a.baltissen_at_kader.hobby.nl
Date: 2000-10-19 21:41:19

Hallo William,

> I'm not sure what you're looking for, but the drives send the directory in
> the form of a program with load address and link addresses.  The first
> part of each line (the blocks used) are sent as line numbers.  These are
> all in hex, not ascii. 
> 
> The directory is loaded into memory as a program.....

Thanks for taking the effort to answer but in fact I know the above. The part 
that handles sending the directory to my CBM is the same one I use for sending 
it to my C64. I only added a part which determines which beginaddress to use 
for which type of C= (C64 $0801, CBM $0401).

In the case of sending the directory it is sent one byte after the other until 
the last three zeros have been sent. Then my program waits for the Untalk. 

The problem starts at the point the CBM starts to send bytes again (for 
whatever reason). And my program is programmed for that way; it quits with an 
error because it sees that the CBM refuses to accept data. The CBM quits with 
an error because for the same reason.

I could build a routine which checks for a ATN-signal, reads the sent bytes of 
the CBM and then resumes it transmition. But I want to know WHY it sends these 
bytes.

To add something to yesterdays info:
I marked two bytes with the markers #1 and #3. I changed my IEEE-monitor to 
check the ATN-line as well and found out that the ATN-line is active (L) at 
these points. But to confuse things more, several runs showed that sometimes 
one of these bytes $48 instead of $00 or $01. This, I think, confirms my 
statement that the CBM wants the attention of the drive while the drive is 
already in the middle of sending a byte. The $48 replacing the $00 can be 
explained as the CBM has already put the data on the databus. But the I would 
have expected a $49 on the place of the $01.

Your opinion please.

Groetjes, Ruud

http://home.hccnet.nl/g.baltissen/index.htm



-
This message was sent through the cbm-hackers mailing list.
To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.

Archive generated by hypermail 2.1.1.