Posted By
Litwr
on 2013-08-08
14:07:29
|  Re: Z80 GUI: SymbOS
Wow! I dare to repeat words from wikipedia "Speedups in the LOAD command of three to five times were typical". These words mean that you should divide your results at least on 5 to get the standard speed. So you can see that without real data the math is the pure speculation only. BTW we should also think about speed of 1MHz 6502 RWTS routines... Commodore data transfer from disk uses two CPU...
The mentioned earlier hardware man who worked with hundreds of Apples insists that the theoretical maximum for the best Apple II turbo loader is 5 KB/sec. This looks good. C1541 maximum is about 3 KB/s.
I've just checked C1551 theoretical maximum. C+4 can get data at rate about 4 KB/s via standard ROM subroutines through parallel interface. I used emulators in the fast IEC mode to get this result. However if we are using special turbo subroutines then the speed may be much better. As I wrote earlier it may be more than 12 KB/s - it is only MHO.
I didn't write that Apple II has little documentation - I wrote that all huge Apple II documentation contains *holes* for the key information. The disk drive data transfer rate (access time, track to track time, ... - did you use these parameters in your math?) is the key information to the description of such kind of hardware. So Apple II is still closed system in this way .
|
