On Wednesday 21 June 2017, 19:29:06 silverdr@wfmh.org.pl wrote: > > On 2017-06-21, at 19:17, Gerrit Heitsch <gerrit@laosinh.s.bawue.de> 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. check this code: https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/VICII/lp-trigger/ -- http://www.hitmen-console.org http://magicdisk.untergrund.net http://www.pokefinder.org http://ar.pokefinder.org Das Schwierigste am Diskutieren ist nicht, den eigenen Standpunkt zu verteidigen, sondern ihn zu kennen. <André Maurois> Message was sent through the cbm-hackers mailing listReceived on 2017-06-21 18:03:51
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