I ett brev frσn 19 Feb 96 skrev Evert de Vos till :
EdV> My clock on my A3000 goes 32 seconds to fast in an hour, which means
EdV> more that one second in 2 minutes, and I think this is just too much!!
EdV> I have a temporary solution with a crontab which does every hour a
EdV> setclock load, but I'm sure there must be a better solution!!
EdV> The tick signal to the CIA comes from the vsync because I'm using a PC
EdV> powersupply, and before that time, I used this already because my
EdV> original PS gave me way too many ticks.
Well, so big errors would show up on all those A500's and A1200's running BBS'es around the world, so i don't think it's a software problem.
EdV> I figured out (just calculated) that vsync gives me 4 ticks too many in
EdV> 9 seconds. Is it possible too adjust this via some sort of system hack
EdV> (substract 4 ticks every 9*50+4 ticks) or something, or is there
EdV> already something like that available?
Have you changed the 'jumper' for PAL/NTSC default screenmode ? You can by software program the agnus to generate both 50Hz (pal) and 60Hz (ntsc) VSYNC's, but it's impossible to get 100% accuracy to the specifications of both PAL and NTSC with one single 28Mhz masterclock, so therefore the PAL machines have a slight slower (of was it faster, anyway) 28Mhz clock than the NTSC machines, to achieve the 100% exact syncronisation frequencies.
The above is fact, and that under this line is just what i believe...
Therefore, the OS uses the PAL/NTSC jumper both to select default screenmode, and also to adjust for the slight frequency difference on the 28MHz clock. If you have flipped the jumper, the OS believes that you also has replaced the 28Mhz oscialator, which you probably didn't.
Is you'r machine direct-imported from the states or so ?
28.37516 MHz is stated on the master-oscillator in my A500, which is defenitly meant to be running PAL, as it originally only had the 0.5Mb PAL agnus, and also has german keyboard. I dunno what's in my A4000 or the A1200 i'm trying to sell of, but it whould be just the same i think.
