Re: GS Problems

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

Galen Tatsuo Komatsu <gkomatsu@Hawaii.Edu> wrote:

> In article <33BEE2B8.7B1E@swbell.net>, Rubywand  <rubywand@swbell.net> wrote:
> >     On a GS with one 3.5" drive, the drive is, usually, accessed at Slot
> >5, Drive 1.
>       so what of the /ram5 ramdisk?  Somewhere I read or saw that it
> shows as being S5 D1.

When the IIgs SmartPort firmware is initialized, it starts out by
assigning /RAM5 (if enabled) to drive 1.  External drives are assigned
after it in order.  (I forget exactly where /ROM5 is placed, if you have
a ROM disk.)

If you have the startup slot set to anything other than "Ramdisk", then
/RAM5 is swapped with the first real drive, so it ends up being drive 2
(S5,D2).  Thus your first external 3.5" drive ends up being drive 1 (the
boot disk for slot 5).

This process is described in the IIgs Firwmare Reference.

> ....on a tangent, just how much memory does this machine have?   The RAM
> card is fully populated, somewhere along the line I figured I had a 1 meg
> total or thereabouts.

The easiest way to find out how much memory you have is to go into the
RAM disk page of the Control Panel.  The total amount of RAM is equal to
the indicated value for the "largest selectable" RAM disk size, plus
256K (the motherboard memory on a ROM 1 IIgs).

> So anyways, I had the /RAM5 disk at about 1 meg and started up Appleworks,
> to my delight it loaded entirely into memory and said I had somewhere
> around 1 meg of memory available.  So then I listed the contents of /ram5
> and it reported back about a meg of free space.  Kinda puzzled.

This sounds like you had the "minimum" and "maximum" sizes set to
different values.  Apple strongly recommends that this not be done, and
removed the capability in ROM version 3.

If, for example, you had set the minimum to zero and the maximum to
1024K, then you would see a 1024K RAM disk which is empty, plus about
1MB of free memory.  As soon as any of that memory starts to get used
(either as a RAM disk or by a program) then it will not be available for
the other potential use.

Say, for example, AppleWorks reserves 512K.  If you subsequently attempt
to save a 512K file to the RAM disk, it will work, but you will now have
no memory left.  Any further attempt to save to the RAM disk produces an
I/O Error.

What is worse is that memory can be fragmented by using the
minimum/maximum feature of the RAM disk: memory reserved by the RAM disk
is permanently allocated, and if it is mixed up with other uses of
memory then you don't have all the free memory in one chunk, which may
limit what can be loaded.  (The only way to clear this is to force the
RAM disk to be wiped, which requires switching the machine off or
initiating a self-test.)

To avoid all of this confusion, set the minimum and maximum sizes to the
same value.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand