Palenicek Jan wrote: > I am working on some timing critical routines for standard QL w/wo > SandyQboard 512 (no GC, no Aurora). Do you know how is memory shared > between CPU and ULA? Do you know how (if at all) is memory delayed > when you need to access videoram at the same time ULA is accessing > it?
I'm no hardware guy, but I'm pretty sure the ULA locks ALL internal memory during screen refresh, i.e. depending on model (EU/US) 50 or 60 times per second. The CPU cannot access anything at all during these times. Some memory expansions like the Trump Card are not as limited, you do not get any delays accessing the extended RAM there. > Is there any emulator emulating that feature? No emulator comes anywhere near a cycle-exact emulation. Emulators providing QL-like speed only arbitrarily slow down the emulation to roughly equal the speed. Marcel _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
