Re: ACOS/BBS

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

In article <41r4tn$gdi@news.rain.org>, Steve Mentzer <stevenm@rain.org> wrote:
> 
>  [ACOS]

Sorry - can't help there.

>  Also, Is it possible to connect SCSI drives to a IIgs these days?

That is a bit of a loaded question.  It has _always_ been possible to
connect a SCSI hard drive to the IIgs.  The original Apple SCSI card
was released at about the same time as the IIgs.

So, I don't quite know whether you mean "is it YET possible" or "is it
STILL possible".

In either case, the answer in yes.  It is getting harder to find the
SCSI cards - you can still buy a RamFast from Sequential Systems, but
Apple have stopped making their original and High Speed SCSI cards.
There may be some stocks of the High Speed card lurking out there
somewhere (Quality Computers was still advertising it somewhat
recently), and resellers such as Alltech Electronics and Shreve
Systems may have either card in stock.

You may be able to pick up either of these cards second hand, e.g.
through the comp.sys.apple2.marketplace group.

There are other third-party SCSI cards, but their software support is
pretty poor.

The RamFast is the best option for ranges of devices supported and
speed.  The Apple High-Speed SCSI card (the one I have) is supported
by Apple's system software, and is the most "standard" SCSI
implementation of the three (except for termination power).

The original Apple SCSI card is much slower than either of the other
cards, and has very limited device support.


Given the SCSI card, all you need is an external SCSI hard drive.
Nearly all SCSI-1 and SCSI-2 hard drives will work fine with a RamFast
or with an Apple HS SCSI card.

> If so, what are the limitations on partition size, etc? 

The ProDOS file system is limited to 32 megabytes per partition.
ProDOS-8 only works with this file system, so it is stuck with this
limit.

GS/OS requires a ProDOS partition for the boot volume, but current
versions can also use the Macintosh HFS file system, which supports
volume sizes up to 2 gigabytes.  There are reports that the IIgs
implementation of HFS is rather flakey when dealing with large
volumes, but 128 megabytes or thereabouts should be safe.  I've had no
trouble with the 100-ish MB partition on my hard drive.

The main disadvantage of an HFS partition is that files on it are not
accessible from ProDOS-8.  HFS is also noticeably slower than ProDOS
when writing files - it seems to take forever to update the directory
information (or work out what it needs to do), but the actual data
transfer is usually much faster than with ProDOS, because the data can
usually be written in a contiguous block without having to preprocess
the data.


A popular choice seems to be selecting a convenient number of 32
megabyte ProDOS partitions, then splitting the rest of the disk up
into one or a few HFS partitions.

I have four ProDOS partitions and one HFS partition on my 240 MB hard
drive.  I have system software and applications on the first, data
files on the second, random stuff (mainly comms) on the third, and PC
Transporter and GNO stuff on the fourth.  The HFS partition has comms
archives and a copy of the data from a developer's CD-ROM.


With the RamFast, all the software needed is built into the ROM on the
card.

The Apple cards use device drivers supplied with the IIgs system
software.  Partitioning and utility functions are handled by programs
included with the system software, or by the software supplied with
the card (which is very rudimentary) for the IIe.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand