|
|
Atari coding BBS
| Re: Synclock & Loading from floppy |
|---|
|
Posted by: Mr. Styckx
|
Nov,14.2012-16:37
|
Hello
to give real numbers on an 8 MHz STF/STE, a 300 RPM floppy drive with a 250000 b/s transfer speed will give 32 microsec to read 1 byte, which in that case means 256 cpu cycles.
So, reading a 512 bytes sector require 256*512 = 131072 cycles (82 % of VBL). It would take a little more time for the FDC to find the correct sector header, but that would not count for more byte to trasfer.
Then FDC will use a double 16 byte FIFO, that will be flushed to RAM every 4096 cycles. So, the DMA will need to steal cycles every 4096 cpu cycles to transfer those 16 bytes (I don't know if the 16 bytes are transferred in one go or spaced somehow)
Nicolas
|
[All messages in this thread] [Start new thread]
|
Topic
|
Posted by
|
Date
|
|
Synclock & Loading from floppy
|
Defjam
|
Nov,05.2012-18:12
|
|
Re: Synclock & Loading from floppy
|
evil
|
Nov,05.2012-21:38
|
|
Re: Synclock & Loading from floppy
|
defjam
|
Nov,06.2012-16:00
|
|
Re: Synclock & Loading from floppy
|
calimero
|
Nov,06.2012-16:05
|
|
Re: Synclock & Loading from floppy
|
ggn
|
Nov,06.2012-20:28
|
|
Re: Synclock & Loading from floppy
|
CiH
|
Nov,05.2012-21:59
|
|
Re: Synclock & Loading from floppy
|
ggn
|
Nov,06.2012-08:34
|
|
Re: Synclock & Loading from floppy
|
Leonard
|
Nov,06.2012-03:12
|
|
Re: Synclock & Loading from floppy
|
Alien / ST-CNX
|
Nov,13.2012-05:59
|
|
Re: Synclock & Loading from floppy
|
Petari
|
Nov,13.2012-16:45
|
|
Re: Synclock & Loading from floppy
|
ggn
|
Nov,13.2012-19:13
|
|
Re: Synclock & Loading from floppy
|
mikro
|
Nov,13.2012-19:18
|
|
Re: Synclock & Loading from floppy
|
Petari
|
Nov,14.2012-11:49
|
|
Re: Synclock & Loading from floppy
|
Mr. Styckx
|
Nov,14.2012-16:37
|
What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
|
