Re: Apple IIgs hardware questions (long, detailed, but worth it - I'm a convert!)

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

Rodney Hester <rod3@mindspring.com> wrote:

> - I understand that ROM 01 is much more compatible with many games than ROM
> 03.  Fair.  This leaves me with two choices - buy a ROM 01 machine, or buy a
> ROM 03 machine and find/beg/borrow a ROM 01 chip and replace it (is this
> possible?).  I'd prefer the latter, since the ROM 03 machine comes with more
> base RAM and a few other enhancements.

As others have noted, ROM 01 and ROM 3 have different motherboards, so
you can't just change the firmware.

I have both machines (my ROM 01 was originally a ROM 00, and was
upgraded).  The ROM 3 is generally nicer to use, as there are enough
minor tweaks to improve it quite a bit.

The game compatibility issue could be a problem, but it only applies to
some native IIgs games which predated the ROM 3 (1989 or thereabouts).
8-bit games should be fine (in fact, some will work better on a ROM 3
than a ROM 1, since ROM 3 has hardware shadowing of text page 2).

The only game I played which exhibited problems was Tunnels of
Armageddon, which couldn't handle some of the mouse speed settings on
the ROM 3; the problem was solved by setting the mouse to run at the
default speed.

Apart from the obvious difference (1.125 MB of RAM built in instead of
256 KB), the other ROM 3 improvements which I regularly benefited from
were:

- Larger ROM means the user interface toolbox mostly runs from ROM,
which is faster than RAM.  This is quite noticeable on an unaccelerated
machine, if you are using native IIgs desktop applications.  Running
recent system software (5.0 or later) on a ROM 1 will tie up more RAM
than the same system on a ROM 3, because ROM 1 has to load more patches
and toolsets into RAM than a ROM 3 would.

- Slot configuration improvements, such as enabling the use of slot 4
for your own card without having to lose access to the built-in mouse.

- Sound hardware is much less noisy.

- The RAM disk is easier to manage (e.g. you can resize it without
having to turn the machine off or do special tricks) and is much faster
than on a ROM 1.

> - Can both the ROM 01 and ROM 03 machines be expanded to the full 8MB of
> possible RAM?

As others have noted, you need to add a memory expansion card.  The slot
was designed to support 4 MB of RAM, so the official limit (with maximum
compatibility) is 4.25 MB for a ROM 1, 5.125 MB for a ROM 3.  These
totals consist of 128 KB of "slow" RAM for each model, plus 128 KB or 1
MB of "fast" RAM on the motherboard, plus 4 MB of "fast" RAM in the
memory expansion card.

Third-party cards can expand the memory as high as 8 MB of "fast" RAM,
but this sacrifices compatiblity with I/O cards which use DMA (with the
exception of the RamFast SCSI card, which uses special techniques to
extend DMA compatiblity with some 8 MB memory expansion cards).

> - Ditto with third-party sound cards like Doctor Design - why would you want
> one with an Ensoniq under the hood?  Would they not also require special
> software?

The built-in hardware only provides a mono output and no easily usable
sound input.  A stereo output card can make use of the Ensoniq and
improve sound quality in some games.  A sound card can also provide
sound input, should you have use for it.

> - If I wanted to plunk my ROM 03-logic-board-based system into a Woz Limited
> Edition case, would it work?  Does anyone ever sell bare Woz cases?

The "Woz" case is just a logo printed on the lid.  (My first IIgs has
one.)

> Ideally, my IIgs system would be configured as follows (pardon my ignorance
> or mistakes, please):
> 
> Apple IIgs CPU (Woz LE case and ROM 03 logic board with ROM 01 ROMs
> installed)
> 2 Apple 3.5" floppy drives (styled for GS)

There isn't much point having two 3.5" drives if you have a hard drive.

> 2 Apple 5.25" floppy drives (styled for GS)

I had one 5.25" drive on my IIgs, and I hardly ever used it (the slot
was usually set to "Your Card", allowing the use of the SuperDrive card
I had in that slot - a high density 3.5" drive is quite useful,
especially if you want to exchange files with a PC).

> Apple color RGB monitor (styled for GS?)

You need the specific monitor which Apple made for the IIgs (or an
equivalent Analog RGB monitor which supports TV-compatible scan
frequencies, i.e. about 15.75 kHz horizontal scan).  You can't use a Mac
RGB monitor, as they don't support low enough horizontal scan rates.

> Apple ADB keyboard/mouse (came with the GS)

An Apple Extended Keyboard is even better, though there wasn't a lot of
software which took advantage of the function keys.  I'm still using my
extended keyboard on a Mac.