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These settings are used to control the hardware-level emulation of the Disk drives. When hardware-level emulation is turned on, only drives 8 and 9 are being emulated.
The following settings affect both drives:
sync_factor = 65536 * clk_drive / clk_machine
where clk_drive
and clk_machine
are clock speeds in MHz.
The menu lets you choose between the PAL and NTSC values, and also lets
you specify whatever value you want. Be careful when changing it,
though, because a wrong value can break things and even corrupt disk
images.
The following settings, instead, are specific of each drive:
The first option (“Skip cycles”) is usually best for performance, as the drive is emulated as little as possible; on the other hand, you may notice sudden slowdowns (when the drive executes several cycles at once) and the LED status is never updated (because it would not be possible to do correctly so). Moreover, if the drive tries to get in sync with the computer in some weird way and the computer does not access the serial line for a long time, it is possible that some cycles are discarded and the sync is lost. Notice that this hack will have no effect on performance if a program continuously reads from the IEC port, as the drive will have to be fully emulated in any case (some stupid programs do this, even when they don’t actually need to use the drive).
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The second option (“Trap idle”) is usually a bit slower, as at least interrupts are always emulated, but ensures the LED state is always updated correctly and always keeps the drive and the computer in sync. On the other hand, if a program installs a non-standard idle loop in the drive, the drive CPU has to be emulated even when not necessary and the global emulation speed is then much slower.
Next: Peripheral settings, Previous: Sound settings, Up: Settings and resources [Contents][Index]