Re: Apple ][c ports?

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

In article <40r0vl$t72@data.interserv.net>,  <davej@ebmud.com> wrote:
> Hello, I am a newbie to apple ][ (sort of a "returnie").
> 
> I have the option to get one or more ][c s to play with. But I will
> need to collect the cables and devices, and the INFORMATION!!

No problem there.  I'm sure we can help.

By the way: this discussion topic is not appropriate on
comp.sys.apple2.programmer, so I've set followups to comp.sys.apple2,
and cross-posted this article there.

> Sooo - where can I get the pin out/in information for the ports on
> the IIc. I am most interested in - power!!, serial and modem ports,
> and mouse/joystick. 

You don't have a power adaptor for the IIc?  It is affectionately
known as the "brick".

The IIc requires an external supply of about +15V DC (the technical
reference manual says it will work with +9V to +20V), at about 1.2
amps.  Maximum power consumption is 25W.

The pinout of the power connector is as follows, looking at the back
of the IIc:

      v
  7       1

6           2

  5       3
      4

Pins 2 and 3 are signal ground, 5 and 6 are power supply input and 4
is shield ground.  Pins 1 and 7 are not connected.

Both serial ports have the same pinout:

5           1

  4       2
      3

1  DTR (flow control out - actually RTS on the internal serial chip)
2  Tx Data
3  Ground
4  Rx Data
5  DSR (flow control in - actually DCD on the internal serial chip)


The mouse/joystick port is compatible with the IIe's joystick port for
a single joystick or a pair of paddles.  Several pins are redefined
for use with a mouse, and it is compatible with the IIe/IIc/Mac Plus
mouse.

5 4 3 2 1
 9 8 7 6

   Mouse     Joystick

1  MOUSEID'  SW1
2  +5V       +5V
3  GND       GND
4  XDIR      do not connect
5  XMOVE     PDL0 (Joystick X)
6  n.c.      n.c.
7  MOUSESW'  SW0
8  YDIR      PDL1 (Joystick Y)
9  YMOVE     do not connect


The disk drive connector is compatible with the IIe UniDisk 5.25 card
or the IIgs disk port: it supports a single external 5.25" drive
and/or one or more UniDisk 3.5 drives (the UniDisk 3.5 must be
connected before any external 5.25" drive, and is not supported by the
original IIc ROM).


The 15-pin video port is intended for use with an external video
generation device or adaptor: it provides several internal video
signals, but cannot be used to directly generate RGB video, for
example.  You need a special device connected very close to the port
to make use of it.

> Are the external disk drives or connections compatible with any Mac
> equipment? 

No.  The Macintosh external 3.5" drive cannot be used on a IIc.  The
only type of 3.5" drive supported by the IIc is the UniDisk 3.5, which
is externally similar to the Apple 3.5 Drive, but has some different
interface electronics, including a built-in microprocessor.

> Is there a way to get the IIc on to an Appletalk network?

No.  Apple were planning to build an AppleTalk interface for the IIc
(it would probably have gone into one of the serial ports, and would
have required an external front-end processor box), but it was never
fully implemented, and the partial support code was removed in later
ROM versions.

> I guess a null modem cable could work to simply transfer ASCII data.

Yes, provided you don't run into flow control or speed problems.  The
original IIc motherboard has a design flaw that causes its serial port
baud rates to be about 3% too slow.  This can cause problems with some
devices, particularly modems.

> Will the old Apple Serial Hard Disk work with the IIc?

I doubt it.  Versions of the IIc that support the UniDisk 3.5 can be
used with SmartPort hard drives such as the Chinook CT-20C and family
(now sold by Sequential Systems), but I don't think the original Apple
HD20 is fully compatible with SmartPort.

To check which version of the IIc you have, get into BASIC and type
PRINT PEEK(64447).  If it says 255, you have the original IIc
motherboard and ROM, which doesn't support SmartPort or the UniDisk 3.5.

ROM version 0 added UniDisk 3.5/SmartPort support.  This ROM can be
installed in the original motherboard after making a simple
modification.  There was also an upgraded motherboard that fixes the
serial port speed mismatch, but this cannot be detected through software.

ROM version 3 adds support for the IIc memory expansion card, which
requires an even newer motherboard with a slot for the card.

ROM version 4 has bug fixes.

The Apple IIc+ reports ROM version 5 with this test.  The IIc+ is
quite a different machine - it has an accelerated processor, an
internal 3.5" drive, support for Apple 3.5 Drives, different serial
connectors and an internal modem connector (never supported).


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