Re: setting GS configuration

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

Joe Cairnes <p035631b@pb.seflin.org> wrote:

> About a year ago I bought an Apple IIGS Owner's Reference and a
> Programmer's Introduction to the Apple IIGS and a (first and only for me)
> GS.  The machine is marked Woz LIMITED EDITION. 
> 
> Before trying to use this system, I thought: that with a GS, 3.5" drives
> were near always connected to a port hardwired to slot 5 and that with a
> GS, 5.25" drives were near always connected to a port hardwired to slot 6.

Not exactly.  The IIgs only has one physical disk port, and its hardware
interface lives in the address space corresponding to slot 6.  You can
connect both 3.5" and 5.25" drives daisy chained to the disk port (up to
two of each).

The firmware for supporting 5.25" drives is also in slot 6, and appears
to software as a Disk ][ controller, with somewhat modified firmware (to
allow continuing the boot process in another slot if there is no disk in
the drive).

The firmware for supporting 3.5" drives (SmartPort) is in slot 5.  It
uses the hardware interface in the slot 6 address space.  If you happen
to have slot 6 set to "Your Card", then the SmartPort firmware access
the disk interface hardware by temporarily enabling the internal slot 6
(Disk Port) with interrupts locked out, then restoring the previous
state.

> My 3.5" drives are all cabled to DB15 connectors.

No they aren't.  For starters, they wouldn't be "DB-15", they would be
"DA-15", if they were 15 pin connectors.  (The "DB" prefix only applies
to a connector which is the same size as the 25-pin one used with serial
ports.)

What you actually have is a 19-pin connector, which doesn't have an
official second letter assignment.  I generally refer to them as a
"D-19".

:-)

> I attached 3.5" drives to a DB15 connector near a hieroglyphic on the GS
> that bears a vague resemblance to a smaller than actual size 5.25"
> diskette. 

That is the (19 pin) disk port.

> I tried to use a Disk ][ and interface in six slots with and without
> memory expansion card installed in memory expansion slot.  (I did not try
> slot 3.) I found that disks could be read only from slot 7. 

This will be due to the Control Panel settings.  The default settings
for the IIgs have an internal feature enabled for all of slots 1 to 6,
and slot 7 defaults to "Your Card", which enables the I/O and firmware
interface for the physical slot.

If you want to use Disk ][ drives on the IIgs, you need to use the Disk
][ controller card, or an adaptor which modifies the cable so that it
can be connected to the D-19 connector.  It is much easier to use the
newer Apple 5.25 Drive, or the UniDisk 5.25, or the Disk //c, all of
which use the D-19 connector.

The big disadvantage of using the Disk ][ controller card in the IIgs is
that you lose the "continue boot" feature of the built-in 5.25" firmware
(see description ablve).

Another important point: you cannot safely use a Disk ][ controller in
slot 1, 2 or 3 of a IIgs, unless you also set the IIgs to run at
"Normal" speed (or restrict use of the drive to within GS/OS, not in any
8-bit software).  The motherboard has hardware to automatically slow
down for a Disk ][ controller in slots 4 to 7, but not for the lower
slots.

> Eventually I stumbled onto a combination keystroke that brought a
> configuration menu display.  The keystroke was something like
> Apple-[RESET].

There are two ways to get into the Control Panel: the "soft" way and the
"hard" way.

The "soft" way is the Control-Apple-Escape key combination.  This calls
up the (Classic) Desk Accessory menu, and lets you select the Control
Panel, Alternate Display Mode, or other CDAs which have been loaded from
disk.  When you quit from the CDA menu, the computer resumes running
where you left off.  Some settings changes will be delayed until you
next restart the computer, notably all the slot settings.

The "hard" way is Control-Option-Reset combination.  This gives you a
menu with four options: enter control panel, set defaults for 60 Hz, set
defaults for 50 Hz, and resume boot.  When you leave the control panel
after entering it this way, the computer will restart, so all changes
apply straight away.

> I reset the slot specs to permit 5.25" disk use in slots  4, 5, and 6.
> But I did not get 3.5" drives to work; perhaps all of them are broken.

To be able to access the 3.5" drives, you must have slot 5 set to "Smart
Port" in the control panel.

> And if I am wrong to expect to be able to print from slot 1, how can I
> print.

The IIgs printer port is mapped to slot 1, and the modem port is mapped
to slot 2.  Both of these use a Mini-DIN-8 connector, and you need the
corresponding slots set to "Printer Port" and "Modem Port" in the
control panel.

If you want to use a parallel interface or a Super Serial Card, you need
the corresponding slot set to "Your Card" in the control panel.

> :-) :-) :-)  Is my experience a demonstration that either ][e or //e is
> the finest computer ever made?  And that I have spent time on an inferior
> item?  :-) :-) :-)

Bite your tongue!  :-)