Re: A2FX, HFSLINK, and Apple 300 CD-ROM on a //e

[dempson@actrix.gen.nz (David Empson)]

In article <1994Sep3.080205.2803@pro-ssor.cts.com>,
Sean Turner <sturner@pro-ssor.cts.com> wrote:
> Is is possible to daisy-chain a Apple 300 CD-ROM on a //e using a HS SCSI
> card and use one or both above programs to transfer files off of the CD-ROM
> disk to a ProDOS hard disk partition?

I don't know the answer to that.  It depends on several factors:

1. Can HFSLink or A2FX handle disk sizes other than 800k (or anything
in that region)? 

2. How many partitions are present on the CD-ROM, and what file system
do they use?

For any hard drive or CD-ROM drive containing at least one ProDOS
partition, the HS SCSI card creates a SmartPort unit for each ProDOS
partition.  Other file systems are not accessible.

If the drive has no ProDOS partitions, but does have an Apple
partition table, the HS SCSI card will only provide a SmartPort unit
to access the first partition.

I'm not sure how it handles a "foreign" partitioning scheme - it
probably treats the entire volume as a single partition, and creates
one SmartPort unit for it.

3. Assuming there is a single HFS partition, how large is it?  If it
is larger than 32 megabytes, you cannot access it via ProDOS-8 block
read calls, and would have to use direct SmartPort calls.  I strongly
doubt that HFSLink and A2FX would do this.

> Has ANYONE EVER written a CD-ROM driver for ProDOS 8 for the Apple HS
> SCSI card?

No need - it is built into the card.  Any limitations will be due to
multiple foreign file systems (or mixed ProDOS/foreign file systems),
and the ProDOS-8 block calls only being able to handle 512 byte blocks
and 32 megabytes.

Anything else requires bypassing ProDOS and calling SmartPort
directly.  If the CD-ROM uses non-standard block sizes, it may be
necessary to use direct SCSI calls to access it.

> In the SCSI manual, one can daisy-chain specifically a CD-ROM,
> scanner, and a LaserWriter to the card, but alas, Apple never wrote
> the software.

It depends which software you mean.  The "driver" for all of these is
built into the card's firmware.  There are no applications to take
advantage of these devices.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand