rhunt@waco.med.unc.edu (Rick Hunt) (03/30/89)
Here is another entry in the 'questions you have answered a
thousand times ' contest.
I have never seen the specs on the disk format for the Amiga and
can't find them anywhere cheap so I'll ask everyone. On the ST
there is a fairly popular utility called twister that staggers the
tracks on a disk by two sectors. The effect is that the disk only
has to complete about 20% of a revolution to return to sector 0 to
start reading the next track instead of having to wait until the
disk does a full revolution. This speeds up disk reading and
writing by 80% or more for large files.
My question is if this is possible or neccessary on the Amiga? I
sure would like to hear it gronk along twice as fast.
Rick Hunt
I would be quite flattered if anyone took my opinion seriously.cmcmanis%pepper@Sun.COM (Chuck McManis) (03/30/89)
In article <416@uncmed.med.unc.edu> rhunt@uncmed.med.unc.edu (Rick Hunt) writes: > Here is another entry in the 'questions you have answered a > thousand times ' contest. [Original question deleted...] > My question is if this is possible or neccessary on the Amiga? I > sure would like to hear it gronk along twice as fast. It is possible, but entirely unneccessary. You see, the Amiga begins reading the track when the head hits the media, when one revolution of data is read in, it uses the blitter to convert from MFM bauds to ones and zeros, and then figures out where the block you wanted was. It never has to wait for sector 0. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you. "A most excellent barbarian ... Genghis Kahn!"
wtm@neoucom.UUCP (Bill Mayhew) (03/31/89)
In article <416@uncmed.med.unc.edu>, rhunt@waco.med.unc.edu (Rick Hunt) writes:
+ ... On the ST
+ there is a fairly popular utility called twister that staggers the
+ tracks on a disk by two sectors. The effect is that the disk only
+ has to complete about 20% of a revolution to return to sector 0 to
+ start reading the next track instead of having to wait until the
+ disk does a full revolution. This speeds up disk reading and
+ writing by 80% or more for large files.
+
+ My question is if this is possible or neccessary on the Amiga? I
+ sure would like to hear it gronk along twice as fast.
+ Rick Hunt
I don't think it would help as much on the Amiga because the
trackdisk.device reads enough to grab an entire track into RAM and
then picks out the individual sectors from the RAM image. At
least, it seems to work that way.
Bill