> On 2017-06-21, at 19:17, Gerrit Heitsch <email@example.com> wrote: > >>> Excellent fun! It sees if the light pen interrupt can be triggered >>> between raster lines x'136 and 2; if so, it's a 6569R1, if not, not. >> That's very interesting too! How does one trigger LP IRQ from within software alone? Is it a kind of raster position / CIA port combination? > > Well, the LP Input is connected to the joystick ports and shares a Pin with PB4 of the CIA on U1. Hardware side sure. What I meant was... > So you can trigger LP IRQs via software. ... that I never used LP IRQs but thought that it would trigger only when the button line is grounded within a specific timing window so some kind of synchronisation with raster position would be required for the IRQ to happen. But that's a different subject anyway. -- SD! - http://e4aws.silverdr.com/ Message was sent through the cbm-hackers mailing listReceived on 2017-06-21 18:03:36
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