Re: C64 won't let me send my data during Talk

From: A. Fachat <>
Date: Mon, 10 Jun 2013 19:25:25 +0200
Message-ID: <>
The iec bus is a real beast. What computer are you using as disk drive 
(sorry if I missed that).

We also had a hard time implementing it on our atmega firmware. See  in the firmware directory.

Do you run with sprites enabled (I  assume not but just in case) ? sprites 
steal more cycles from the cpu than normally. Add a vicii bad line and you 
may run out of the spec of the IEC bus.
To check that you could try the same program with sprites off,  or the 
whole screen off and see if it still doesn't work.

Otherwise I would try to start from the drive code 1:1 and if that works 
modify the code into the direction you want and see when it breaks.


Am 10. Juni 2013 18:58:45 schrieb Jim Brain <>:
> On 6/10/2013 11:15 AM, Chris Osborn wrote:
> > On Jun 10, 2013, at 8:27 AM, Michał Pleban wrote:
> >> Any chance you could use an oscilloscope to see what the 1541 is doing
> >> with the lines and compare to your signals?
> > I'd have to find a logic analyzer. My oscilloscope is an old Tek 453 and 
> without a repeating signal I'll never see it.
> >         Message was sent through the cbm-hackers mailing list
> Let me recommend Saleae's Logic or Logic16 units.  Cross platform, cheap, 
> and very useful for classic machine use.
> Jim
> -- Jim Brain
>        Message was sent through the cbm-hackers mailing list

       Message was sent through the cbm-hackers mailing list
Received on 2013-06-10 18:02:14

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