Re: More dumb questions from GS "newbie"

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

Michael Elliott <cv985@FreeNet.Carleton.CA> wrote:

> I am in the process of aquiring a GS and have some "dumb"
> questions. I have used a IIe and ProDOS 8 for years, but some
> of the finer points of the GS elude me. I have read Nathan's
> faq, but still am unclear about:
> 
> 1) How are the slots "used" when attaching devices to the
> ports

The IIgs has seven slots (not counting the memory expansion slot), which
are almost identical to the seven numbered slots in the IIe (the IIgs is
missing a couple of obscure signals and replaces them with more useful
ones).

Each slot also has a corresponding built-in peripheral.  The IIe already
has a simple version of this: the 80-column firmware is built into the
motherboard and associated with slot 3.  You can either use the built-in
80-column firmware, or plug a card into slot 3 and lose the built-in
firmware (this is somewhat of a simplification - it depends what sort of
card you install).

On the original IIgs (256K motherboard, ROM version 00 or 01), the
built-in peripherals associated with each slot are:

Slot 1: Printer Port
Slot 2: Modem Port
Slot 3: 80-column firmware
Slot 4: Mouse firmware
Slot 5: Smartport firmware (3.5" drives, RAM disk, etc.)
Slot 6: 5.25" drive interface
Slot 7: AppleTalk firmware

ROM version 3 (the 1MB IIgs motherboard) is very similar, but AppleTalk
now lives in slot 1 or 2, and can also appear in slot 7 (but this wastes
a slot and is only intended for compatibility with badly written
software).

The exact rules for using the slots vary somewhat between slots and IIgs
models, and also depend on the cards you intend to use.

Here are a few guidelines.

1. If the card does not contain any firmware or I/O in the slot address
space, then you can put it in any slot without interfering with the
built-in function.  An example of this are the TransWarp GS and Zip GS
accelerators, and most IIgs stereo cards.

2. If the card does not contain any firmware but does use the slot I/O,
then you might be able to put it in slot 3 or 4 without losing the
built-in function.  This depends on how the software for the card
operates.  Some cards in this category can be used in other slots, and
they dynamically switch slots while accessing the card.  (This is rare.)

3. In most other cases, you must set the slot to "Your Card", and you
lose the built-in function.

4. Some cards can only be used in specific slots, because of special
motherboard signals.  In particular, the Video Overlay Card and Second
Sight card can only be used in slot 3 on a ROM 00/01 machine (unless you
run a wire to get a missing signal).  On a ROM 3 machine, these cards
can be used in slots 1 to 6.  They cannot be used in slot 7 on any
machine, because the pin in question is used for a different signal.


Changes to the slot settings only take effect when you next boot the
computer.

If you have a rarely used internal device or a rarely used interface
card, then you can usually set things up so that you change slot
settings and reboot when you want to use the device.

A good example of this is the 5.25" drive firmware: for quite a long
time, I have used the 5.25" drive at most once a month.  I was quite
happy to put another card into slot 6 (my SuperDrive controller card)
because I would not need it at the same time as the 5.25" drive.  I
simply change slot 6 between "Disk Port" and "Your Card" as required.


Some special rules about the built-in peripherals:

AppleTalk actually uses the Printer or Modem port, so you cannot have
Printer, Modem and AppleTalk enabled simultaneously.

On the ROM 00/01 machine, you must set either slot 1 or 2 to "Your Card"
when you enable AppleTalk (in slot 7).  AppleTalk uses the port
corresponding to the lowest numbered slot which is set to "Your Card".

On the ROM 3 machine, you choose between Printer, Modem, AppleTalk or
Your Card for both slots 1 and 2.  The "Printer" and "Modem" settings
refer to the configuration of the serial firmware (this is selected on a
different Control Panel screen for the ROM 00/01).

The ROM 3 IIgs has another benefit: you can set slot 4 to "Your Card"
and retain the use of the ADB mouse in IIgs desktop programs.  You still
lose it in ProDOS-8 applications.  This has given me an extra slot.

On a ROM 00/01 IIgs, you lose the mouse completely if you set slot 4 to
"Your Card".

> (for instance, if I plugged in a printer, modem, 3.5 and
> 5.25" drives, and hard disk, how many slots would I have "left"?

You would have used up slots 1, 2, 3, 5 and 6 for built-in functions.
The hard drive could go in slot 7, and you would probably want to use
slot 4 for the mouse (either built-in or a IIe mouse card).  You would
therefore have no slots left.

However, you could still install an accelerator or stereo card in any
unused slots.

> 2) I know an ADB mouse is preferable, but will a IIe mouse card and
> mouse work in a slot on the GS? (at least for ProDOS 8 programs)?

On the ROM 00/01 IIgs, 16-bit IIgs software (GS/OS or ProDOS-16)
supports either an ADB mouse or a IIe mouse.  The toolbox searches the
slots to locate the mouse interface.  Some software might assume the
mouse is in slot 4, so it is best if you can install the mouse card in
this slot.  Most 8-bit applications will correctly search for the mouse.

On the ROM 3 IIgs, 16-bit IIgs software will only work with the ADB
mouse.  If you install a IIe mouse card, it will be used by 8-bit
software, so you will probably need two mice.  (You can put the IIe
mouse card in slot 4, so you don't lose a slot.)

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