Re: GS user gets free Mac -- some questions....

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

In article <Cusw1M.97p@maplesoft.on.ca>,
Tim Haynes <thaynes@maplesoft.on.ca> wrote:
> Greetings, fellow Apple II zealots...
> 
> I haven recently come into possession of a little Macintosh Plus (I got it
> for free).  I also picked up a free 40 meg SCSI drive (no case, cables, 
> power supply or anything -- just the drive mechanism).  I've only owned 
> Apple II's, but have used Macs at work.  I have a few questions that I'm 
> hoping some kind soul here can help me with...
> 
> 1) what do I need to get the 40 meg hard drive useable on my GS?  Some
>    type of SCSI card, but which is the best?  Is it feasible that I can
>    sell this little Mac and use the proceeds to get such a card?

Yes.  All you should need is a SCSI card and a cable to connect the
drive to the computer.  You may also need a SCSI terminator (a small
device which plugs onto the back of the drive).

The following SCSI cards are still commercially available from various
mail-order sources:

Apple High-Speed SCSI card     US$120 ish
RamFast SCSI card              US$140 ish

The RamFast is almost always faster than the Apple card, because it
has cache memory on the card.  Both cards support Direct Memory
Access, but this can be switched off if you have other hardware (such
as a memory card) which is not DMA compatible.

There is also an older SCSI card from Apple, which is a lot slower
than either of the above, but should be much cheaper.  It works with
current software, provided it has the latest version of the ROM
(revision C).  This card is called the "Apple SCSI card" (or "Original
Apple SCSI card").  The Revision C ROM can be identified by the number
341-0437-A on the EPROM label.

The original Apple card will work in a II+, unenhanced IIe, enhanced
IIe or IIgs.

The Apple High Speed card will work in an enhanced IIe or IIgs.

The RamFast card works in a IIgs.  Some versions can also be used in
the IIe, but I'm not sure of the exact details.

> 2) what's the largest partition on a Prodos volume?

32 megabytes is the largest the ProDOS file system can support.  With
current versions of ProDOS-8 and GS/OS, you can have lots of
partitions with any of the above SCSI cards.

With IIgs System 6.0 or later, under GS/OS, you have the option of
setting up an HFS partition.  HFS is the file system used by the
Macintosh, and it supports partition sizes up to at least 2 gigabytes.
It also has much more flexible file naming rules than ProDOS.  Note
that you cannot access an HFS volume from ProDOS-8 programs, and your
first (boot) partition must be ProDOS-formatted.

As an example, I have a 240MB SCSI drive, divided into four 32
megabyte ProDOS partitions, and a 92 megabyte HFS partition.
 
> and lastly, the Blasphemy Of Ages...
> 
> 3) isn't a 68000 faster than a 68C816?

Yes, assuming comparable clock speeds.  As a very rough rule of thumb,
multiply the 65816 clock speed by about 3 to get a comparable speed
for a 68000, 8088 or 8086.  This ratio breaks down with more powerful
processors (68020, etc., and 80286, etc.).

A Mac Plus and IIgs are very similar in apparent execution speed,
though the Mac Plus is a little faster at doing calculations.  The Mac
Plus's 68000 runs at roughly 7.8 MHz.  The IIgs's 65816 runs at
roughly 2.6 MHz, depending on what is happening.

>    Is it conceivable that this little Mac is a better equipped
>    machine than my GS?  My GS is very stock -- 1 meg RAM, 800k drive,
>    no hard drive, colour composite monitor (yak!)

It depends what you want to use the computer for.  The Mac Plus has NO
colour support (not even greyscale - only black and white) and its
sound is very primitive compared to the IIgs.

A fully populated Mac Plus (4 MB of RAM) can probably run a lot more
software than the IIgs, because of the larger Macintosh market, but it
is rapidly becoming obsolete, as most new software expects a
colour-capable machine and the latest system software, which doesn't
leave much memory on a 4MB machine.

On the other hand, a 4 MB IIgs with a hard drive is a top-end machine,
able to run practically all II+, IIe, IIc and IIgs software, and is
much more fun!  :-)

There are a few things you can use the Mac for, which aren't possible
on the IIgs [yet].  In paritcular, if you set up an AppleTalk network,
the Mac Plus can act as a slow file server, either using dedicated
AppleShare software (expensive, but allows a IIgs to be booted via the
network), or with the Personal File Sharing features of Mac System 7.

>    I guess putting this hard drive on the Mac is easier than putting it on
>    the GS -- any personal opinions about whether it's worth it to put  
>    the hard drive on the Mac and actually *use* the thing?  I was going to
>    use the Mac as a terminal, but....
> 
> I'm also wonder what the cash value of this item is (minus the hard
> drive).  

Not much.  Mac Pluses without hard drives are going for less than
NZ$400 here (US$250ish).  This really annoys the people who bought
them for over NZ$10000 when they first came out.  :-)

If it has a lot of RAM, you might get more for it.  On the other hand,
you could buy a memory card for the IIgs which uses SIMMs, and steal
the RAM out of the Mac Plus.  (The OctoRAM and the Q-RAM come to mind.)
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand