Re: Apple//c newbie questions

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

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

> In article <%KyS1.138221$RC5.12955281@news.rdc1.bc.wave.home.com>,
> David Cross <dcross1@nospam.home.com> wrote:
> >An Apple ][+ with the old Disk ][ controller card (a collectors item these
> >days!) would be able to boot such a disk.
>       Is there anything notable to distinguish them from a not-old
> Disk ][ controller?
> 
> >Almost all software written for the ][+ will work on a //c as long as it
> >is on a DOS 3.3 or ProDOS disk.
> 
>       Will BOOT13 from the DOS3.3 System Master disk work for 13 sector
> floppies?

I can't think of any reason why not.  The IIc disk controller chip (IWM)
is a superset of the Disk ][ controller card and is fully compatible for
everything that obeys the access rules.

> ...and I have some questions myself (guess who else got a //c recently?)
> since the library's copy of the tech ref is currently loaned out.
> 
>       Just what do the Keyboard and 40/80 buttons do?

The 40/80 button selects the number of screen columns that will be
displayed by default.  I'm not sure when this is actually checked -
probably when booting ProDOS-8 and launching BASIC.SYSTEM.

The keyboard button selects one of two keyboard layouts.  For an
international IIc, this chooses between the US and local layouts.  For a
US IIc I believe it chooses between Dvorak and standard (Sholes).

>       Is ctrl-CA-reset supposed to do nothing now?

It depends on the firmware version.  The original IIc has an extrememly
minimal self-test that doesn't really test anything - It just displays
patterns on the screen.  Any upgraded version will do a proper self-test
if you use Ctrl-CA-Reset.

Note that you have to hold down the closed apple key after letting go of
either Ctrl or Reset to be certain that the computer detects it.

>       What does the external floppy connector accept?

All versions of the IIc accept a single external 5.25" drive, which is
any of:

Apple IIc 5.25" drive (has no daisy-chain connector)
UniDisk 5.25
Apple 5.25 Drive
Disk ][ with an adaptor cable

If you have any firmware version _except_ the original firmware, you can
also connect up to four UniDisk 3.5 drives.  If you want to connect both
a UniDisk 3.5 and external 5.25" drive, the UniDisk 3.5 must go first,
and the 5.25" drive must be daisy-chained to it.

In addition to the UniDisk 3.5, you can connect any intelligent drive
that supports the SmartPort protocol.  As far as I know, the only such
drive is the Chinook CT-20C, which is a 20MB hard drive.  It was later
sold by Sequential Systems.  Note that SmartPort is very slow compared
to SCSI, so this is a rather poor substitute.

The IIc does not support the Apple 3.5 Drive or SuperDrive.  (Note that
the IIc+ _does_ support the Apple 3.5 drive.)

To find out which firmware version you have, get into BASIC and type
PRINT PEEK(64447).

255   Original firmware
0     UniDisk 3.5 support
3     Memory expansion card (newer motherboard with an extra slot)
4     Bug fix release for version 3
5     Apple IIc+ (almost a completely different computer)

If you have the original firmware you probably also have the original
motherboard.  This has a design flaw in the serial ports which means
that they run about 3% slower than the standard (e.g. "9600" is actually
9320 bits per second).  This has compatibility problems with some
devices, in particular most modems faster than 300 bps.

Later motherboards add a crystal with the correct speed, resulting in
much better behaviour.

>       Will the RGB port work with the monitor on my GS?

It isn't an RGB port at all.  It is a video expansion port.  The only
display device that plugs directly into it is the IIc LCD display.
Anything else needs an adaptor to generate the appropriate video signal.

It is possible to get both analog and digital RGB adaptors.

>       Does it take a special mouse, or is it the same one as with the
> //e and early Macs?

Exactly the same mouse.  Note that you can also connect a IIe joystick
to the same port.  (If you have a mouse connected, the firmware can make
it emulate a joystick for software that uses the standard PREAD routine
in the monitor.)

>       The LCD Flat Panel Display (no, I didn't get one with my //c =^)
> I'm just wondering...) does it draw its power from the video signal or
> requires it's own source?

Can't answer that one.

>       Any notable quirks/differences to tell someone who's been using
> a //e most of his life?  (Besides the physical attributes and lack of
> slots. =^)

The serial ports are somewhat limited compared to a Super Serial Card
(on which they are based): there is only one flow control line in each
direction, connected to the DCD and RTS pins on the 6551 ACIA.  The DSR
signal on each ACIA is used internally by the IIc.

There is a support for a vertical blanking interrupt, and the built-in
mouse support (which takes up a lot of CPU time compared to the IIe and
IIgs implementations).

The boot sequence will try the 5.25" internal drive, then an external
UniDisk 3.5.  (The standard Disk ][ controller or derivatives will wait
forever for a disk to be inserted.)

The monitor firmware has a lot more features than the IIe, including
support for 65C02 instructions.  It is even better if you have the
UniDisk firmware release or later.

Otherwise the IIc is pretty much identical to an enhanced IIe with the
appropriate devices in the various slots.

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