Re: Some Apple // hardware questions!

[pubpc1@library.ucla.edu]

kelsey@mail.wsu.edu (Michael Kelsey) wrote:
>I have been away from my Apple //e for far too long and I have numerous
>questions about hardward I have obtained.  These questions involve SCSI
>drives, ethernet, and external drives.
>
>Being in the PC world for over 4 years and adapting my computer to SCSI
>[for obvious reasons] I have acquired numerous hard drives, all around the
>size of 40MB, perfect for an Apple //e.  I already own a [lousy AEC] SCSI
>interface that can detect devices on various IDs, however the slot ROM is
>limited to only two drives or two partitions.  I have about 6 different
>drives that I would like to use with my Apple //e since these drives
>truly serve no purpose in my PC system.  I am aware there exists the
>RAMFast Rev. C and D, where Rev. D is tailored for the GS.  If I were to
>purchase a RAMFast card for my Apple //e would ProDOS recognize more than
>two drives?  Are there any SCSI adapters for the //e that will allow for
>more than two drives?  I quickly parsed the four part FAQ and I saw no
>limitation based on the number of ProDOS devices [ProDOS 8 is assumed]
>when using the RAMFast interface.

Michael, the RAMFast can recognize seven devices on its chain.  It
overcomes the 2 volume per slot limit by remapping the extra volumes
to other slots.  The maximum number of volumes on the SCSI chain, I
believe, is 12.  These can be partitions divided up between the seven
SCSI drives on the chain (for example, six drives with two partitions
each).  If you exceed 12 partitions, all is still fine because you
can go pick and choose which 12 are active for a given session.

The Apple II High Speed SCSI card is even more flexible, but only on
a GS.  The card is capable of recognizing 111 volumes.  GS/OS itself
recognizes around 63 volumes max.  On a IIe with ProDOS 8, the number
of volumes are limited to 14 max.  However, since the floppy drive
and /RAM (S3, D1) eat up two volumes, you are left with 12 accessable,
so you gain nothing over the RamFAST.

>A Macintosh external 800K drive [in good condition] has also come into my
>possession.  I have read documentation and posts about the UniDisk
>[different from the external 800K drives] and I realize that this external
>drive lacks the processor needed to handle the transfer for the Apple //e.
>Is there an interface that will support this external 800K drive?

Yes, you need a Universal Disk Controller (aka. UDC) card.

It drives practically all the different types of 3.5" drives, except
that the later revisions of the firmware can't handle UniDisk 3.5's
(the ones with the CPUs in them), but only GS and Mac "dumb" drives.

 
>Would it be possible to transfer data between a PC and the Apple //e if
>I could interface the drive with the Apple?  Naturally the floppy would need
>to be formatted by the PC as 720K.  Would Apple II File Exchange [I forget
>the exact name] be able to read the 720K PC disk, or would I have to write
>my own driver for ProDOS?

There is a program for doing this, but it only works with a 1.44MB
drive and controller card.  With a SuperDrive, you will be able to
read and write 1.44MB and 720K MFM disks.  Also, 1.44MB ProDOS disks
can be read on the PC with the MS-DOS program ProCopy.

Alternatively, you can connect a standard IBM PC floppy 3.5" high
density drive to your IIe with the addition of a BlueDisk card.  Still
being manufactured, the contact information for the company that sells
it is in the FAQ.


>For purposes of longevity and the advent of excellent Apple II emulators,
>I am seeking a means to transfer [and backup] my Apple II software onto a
>CD-ROM.  Naturally the CD-ROM would be formatted and "written" in ISO-9660
>and a return transfer would be required to restore data.  A convenient
>means would be some form of Ethernet adapter. The recently posted FAQ
>mentions a propietary Ethernet adapter in the works, but no mention of any
>references.  I consider myself to be quite adept at 65C02 assembly,
>therefore, coding protocol layers wouldn't be a simple task, but it would
>not be an impossibility.

There was talk about this several months ago.  The RamFAST and the
original Apple II SCSI cards apparently lack some SCSI features that
make SCSI to Ethernet adapter drivers infeasable.  The only SCSI card
that theoretically works in hardware for this purpose is the Apple II
High Speed (DMA) SCSI card.  However, no driver software for any of
the adapters out there have been written.

You could get an Apple II High Speed SCSI card if you want to try to
write the software for an Ethernet link.


>Currently, my only avenue is through RS-232
>peaking at a lowly 19200 baud rate.  If I could place the files on disk
>[with the external drive mentioned above] through the use of the
>accelerated floppy driver with Windows '95 I would have no problems
>achieving a read rate of >15K/sec [greater than 115200 baud].
>Nonetheless, I would still risk barriers in data corruption due to
>transferring with physical media.  I would like to know if there are any
>avenues besides null-modem and floppy media.

Sure, but it requires an Apple IIGS.  You could get a GS logic board
from Shreeve Systems and drop it into your IIe case to upgrade it.
Steve Buggie has written an article about how to do this as well.

With a GS in the picture, you can use HFS formatted Iomega Zip Disks
as a transfer medium between the computers.  There are addons on the
PC side that can read and write Macintosh HFS media.  The GS has
Macintosh HFS capability via the GS/OS HFS FST (filesystem translator)
that's an integrated part of its system software.

>GCR versus MFM.  This does seem to be a "neat" avenue for data transfer,
>however, fruitless based on the phyical incompatibilites of the media. A
>while back I formatted an PC diskette, single-sided, single density at
>160K.  I wrote an obvious disk pattern, consisting of 0xA0 and a variety
>of other disk bytes.  I am aware of the Disk II's inability to realiably
>read zero bytes, and with wear and tear I'm sure the accuracy of my drives
>[which currently read zero bytes quite well] will fade.  Despite the
>incompatibilities of the hardware, would it be possible to write disk data
>bytes such that they pattern written to disk could become legible by
>either platform?  My idea is to have the Apple II write the proper disk
>pattern.  If programmed correctly, the Apple II drives can write virtually
>any pattern of disk data, but will the "envelope" of encoding prevent me
>from achieving data transfer?
>
>Any assistance is greatly appreciated!
>
>/\/\ichael |<elsey
>kelsey@mail.wsu.edu

Your best bet is probably to try to get either a BlueDisk controller
from SHH Systeme and connect IBM floppy disk drives (both 3.5" and
5.25") to your IIe.  Then you can write 3.5" _MFM_ format 1.44MB floppy
ProDOS disks.  These disks can be read on the PC with ProCopy.

-Scott G.