ccastbs@prism.gatech.EDU (Shannon Bell) (12/14/89)
Does anyone know why a disk II controller with two drives will work
perfectly in slot 6 of a GS but not in slots 1 or 2?
In slots 1 or 2, a catalog registers the disk as disk volume 001 and
gives an i/o error at track $11. The main problem with this is that
the disks are freshly formatted prodos disks.
Is there something special about the slot 1/2 architecture, relative to
the slot 6 architecture, that would prevent the proper functioning of
a Disk II contoller?
Shannon Bell
PO Box 36266 Georgia Institute of Technology, Atlanta Georgia, 30332
uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!ccastbs
Internet: ccastbs@prism.gatech.edumattd@Apple.COM (Matt Deatherage) (12/15/89)
In article <4366@hydra.gatech.EDU> ccastbs@prism.gatech.EDU (Shannon Bell) writes: >Does anyone know why a disk II controller with two drives will work >perfectly in slot 6 of a GS but not in slots 1 or 2? > >Shannon Bell In short (really), yes. The computer has circuitry in it to allow it to slow back down to 1 MHz (from 2.8) when a Disk II motor on switch is detected, but that circuitry is only functional for slots 4, 5, 6 and 7. (IIgs Hardware Reference, pages 20-21.) Either move your Disk II card to one of those slots or always run your IIgs at "normal" (slow) speed. -- ----------------------------------------------------------------------------- Matt Deatherage, Apple Computer, Inc. | "The opinions expressed in this tome Send PERSONAL mail ONLY (please) to: | should not be construed to imply that Amer. Online: Matt DTS | Apple Computer, Inc., or any of its ThisNet: mattd@apple.com | subsidiaries, in whole or in part, ThatNet: (stuff)!ames!apple!mattd | have any opinion on any subject." Other mail by request only, please. | "So there." -----------------------------------------------------------------------------
jerryk@pro-tcc.cts.com (Jerry E. Kindall) (12/15/89)
In-Reply-To: message from ccastbs@prism.gatech.EDU The fact that you say a catalog registers a disk volume as 001 and gives an I/O error at track $11 indicates that you're using DOS 3.3 to try to read a ProDOS disk. ProDOS does not show a disk volume when you try to catalog a disk. Or are you using Copy II+? _____ ||___|| Jerry Kindall | Internet: jerryk@pro-tcc.cts.com | o | 2612 Queensway Drive | UUCP: nosc!crash!pro-tcc!jerryk |__O__| Grove City, OH 43123-3347 | GEnie: A2.JERRY ALine: A2 Jerry
blochowi@rt1.cs.wisc.edu (Jason Blochowiak) (12/16/89)
In article <4366@hydra.gatech.EDU> ccastbs@prism.gatech.EDU (Shannon Bell) writes: >Does anyone know why a disk II controller with two drives will work >perfectly in slot 6 of a GS but not in slots 1 or 2? > [Deleted mention of read errors] >Is there something special about the slot 1/2 architecture, relative to >the slot 6 architecture, that would prevent the proper functioning of >a Disk II contoller? Well, the //gs runs faster (~1.5Mhz faster) than the other Apple //'s, so Apple had to do some relatively strange stuff to get the disk drives (which use timing dependent software) to work properly. Basically what happens is: when the //gs sees software turn the drive motor on, it slows the machine down to 1Mhz (the "standard" // speed) so that the timing works correctly, and speeds it back up when the motor gets turned off. For various reasons, this automatic slowdown is only available in slots 5-7, so when you put the controller card in slot 2, the //gs tries to run the software at full blast, which doesn't work out right - I think (not at all sure on this one) that if you set the system speed to "Normal" (in the Control Panel) the card will work in slot 1 or 2. >Shannon Bell >Internet: ccastbs@prism.gatech.edu -- Jason Blochowiak - blochowi@garfield.cs.wisc.edu or jason@madnix.uucp "Education, like neurosis, begins at home." - Milton R. Sapirstein