Hi, This is what I think is the real story on US QL interrupt frequency. This is all from memory and also I might be wrong!!
The US QL has both 50 and 60 Hz poll, depending on the chosen display (F1 or F2). F1/monitor would have the QL work at 50Hz while F2/TV will force a 60Hz frequency. What makes me think this ? Well first I did tests on the PAUSE Sbasic command. In TV mode PAUSE 60 would last one second (of course mesured over a long period of time) and in Monitor mode 4 (F1) PAUSE 50 would last one second. Also, a normal American TV or monitor would work OK in mode 8 (F2) but with less horizontal line (192 ?) while it would need adjustment to work in mode 4. Also, the flickering was nicer on the eyes in mode 8 compare to mode 4 (60Hz relative to 50Hz) This of course was only with a standard JSU rom. With minerva or SMSQ/E the QL would always be in 50Hz poll, whatever the mode. Regards, Francois Lanciault ZN wrote: > first, because a US QL would not be able to display a whole 256 line screen > reliably because there are only 262 lines total in each, and second, a > separate 50Hz oscillator would be needed to supply the poll interrupt > frequency for QDOS. No, US QLs have a 60Hz poll. Marcel
