ted@hpwrce.HP.COM ( Ted Johnson) (01/19/90)
I just noticed that my SE (running 6.1/6.0.3) doesn't do double buffering when copying files from a floppy to the internal hard disk. Is there some technical reason why the Finder doesn't do this? Seems like this would be a cheap way to get a performance increase.... DESIRED SCENARIO: 1)read from floppy (hard disk remains idle) 2)write to hard disk (floppy drive remains idle) 3)if not done, goto 1 DESIRED SCENARIO: 1)do an asynchronous read from floppy to memory buffer A; In the meantime, the previous read from floppy, which was stored in memory buffer B, gets written to the hard disk. 2)when the async. read from floppy completes, it interrupts and then the hard disk reads from buffer A to the hard disk. Meanwhile the floppy drive starts a new async. read, moving the bytes read to buffer B. 3)if not done, goto 1 -Ted
6500stom@hub.UUCP (David Stoms) (01/20/90)
> 1)do an asynchronous read from floppy to memory buffer A; > In the meantime, the previous read from floppy, which was stored in > memory buffer B, gets written to the hard disk. As far as I know, none of the disk drives (floppy or HD) support async reads or writes. Hopefully, Apple has realized this and is working to correct it. / Josh Pritikin T The C++ programming language \ | Internet: 6500stom@ucsbuxa.ucsb.edu | is at worst, the second best | | AppleLink: Josh.P | for a given application. | \ GEnie: J.Pritikin ! But usually, it is the best. /
amanda@mermaid.intercon.com (Amanda Walker) (01/22/90)
In article <3655@hub.UUCP>, 6500stom@hub.UUCP (David Stoms) writes: > As far as I know, none of the disk drives (floppy or HD) support > async reads or writes. Actually, I believe that the File Manager does not support asynchronous reads or writes, only the Device Manager. Especially under MultiFinder, it sure would be nice to be able to do it, though. Sigh. Amanda Walker InterCon Systems Corporation --
chewy@apple.com (Paul Snively) (01/23/90)
In article <3655@hub.UUCP> 6500stom@hub.UUCP (David Stoms) writes: > > 1)do an asynchronous read from floppy to memory buffer A; > > In the meantime, the previous read from floppy, which was stored in > > memory buffer B, gets written to the hard disk. > > As far as I know, none of the disk drives (floppy or HD) support > async reads or writes. Hopefully, Apple has realized this and is > working to correct it. You're half right; the .Sony driver actually does support async I/O to/from the floppies. __________________________________________________________________________ Just because I work for Apple Computer, Inc. doesn't mean that they believe what I believe or vice-versa. __________________________________________________________________________ C++ -- The language in which only friends can access your private members. __________________________________________________________________________