Re: cassette port dongle

From: Glenn Holmer (
Date: 2006-08-27 17:38:46

On Saturday 26 August 2006 22:43, William Levak wrote:
> On Sat, 26 Aug 2006, Glenn Holmer wrote:
> > I have a piece of software that uses a cassette port dongle (KMMM
> > Pascal), and would like to make an unprotected copy of it.  What
> > should I be looking for in terms of register reads &c. that they
> > would be using to detect the dongle?
> You don't say which computer it is for.

Sorry, C64.

> Dongles have a capacitor and transistor across several of the lines,
> so that a signal output on one line that will appear a short tome
> later (determined by the capacitor) on a different line (determined
> by the transistor). The actual lines are different for each dongle.
> You are looking for a short machine language routine that outputs to
> the cassette port, and then waits for a reply.

I am not sure which registers...  Looking at Marko's I/O map, I see bits 
3, 4, and 5 of $01 and bit 4 of $DC0D, I will start looking for reads 
to these addresses.

Glenn Holmer (Q-Link: ShadowM)

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