[Coco] Sdc question

Barry Nelson barry.nelson at amobiledevice.com
Tue May 26 19:51:51 EDT 2015

 I booted the system from a DriveWire server, but there are other cases where there mightn't be a disk inserted. For example, I could have the sdc command loaded into memory, and then if I accidentally oopsed and ejected my system disk, I could reinsert it, or a different one. With the proper device descriptors and drivers, I could also boot off a real floppy disk in attached to a floppy controller in a different multipack slot. There is also my old Burke & Burke controller, but I doubt I would hook that up again as I have long since dumped everything on that old hard drive to a disk image. The biggest reason is to allow you to insert a disk if you accidentally eject the last one. Thanks for the suggestion with I$Attach, I did try that, to no avail. I wonder if this is an issue with the way the driver is working?

On May 26, 2015, at 7:39 PM, coco-request at maltedmedia.com wrote:

> Date: Tue, 26 May 2015 16:45:59 -0600
> From: Darren A <mechacoco at gmail.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Subject: Re: [Coco] Sdc question
> Message-ID:
> 	<CAE8FjTZ=Qi5rQ6B_P5iEH0YQDHXKEkTWyMXdAEmQT6S7GMdJ+w at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
> On Tue, May 26, 2015 at 2:20 PM, Barry Nelson wrote:
>>>> Can anyone help with the issue I have opening the device? Will I have to
>>>> talk to the hardware directly?
>>> Opening /sd0@ for reading should work.  Tim Lindner's latest version of
>>> SDIR uses the following code to open the device:
>>> sdcPathName
>>>    fcc    ./sd0 at .
>>>    fcb    C$CR
>>> * open path to driver
>>> * uses A, X
>>> open_path_to_driver
>>>    leax   sdcPathName,pc
>>>    lda    READ.+PREAD.     open for reading
>>>    os9    I$Open
>>>    lbcs   noDriverError    Fail if not opened
>>>    sta    pathnumber,u
>>>    rts
>>> - Darren
>> That only works if there is a "disk" inserted. If there is no media
>> inserted, then that yields an error 246.
> I'm very much a novice when it comes to OS9, so take everything written
> here with a large grain of salt.
> If there is no disk inserted in /sd0 then I assume you didn't boot the
> system from the SDC or you booted from a "floppy disk" image. In the latter
> case I would warn against using any SDC-specific tools since its unsafe to
> have both a floppy descriptor and an sdc descriptor referencing the same
> hardware.
> If you have booted the system from some other device then there is the
> question of whether or not the descriptor and driver modules for the SDC
> are available and have been loaded as part of the boot process. If the
> modules have been loaded and I$Open still fails, then perhaps a call to
> I$Attach is needed to make sure the driver has been prepared for use.
> - Darren

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