Re: Apple IIe newbie needs help

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

In article <39pca3$be@mhaao.inhouse.compuserve.com>,
Mark Dolecki <mdolecki@csi.compuserve.com> wrote:
> Hi folks.  I just picked up an old Apple IIe for $15 the other day, and
> I was wondering if someone can give me a little more info than was in the
> FAQ.  I know what the thing can do (used to use them alot a few years ago),
> but I don't have any documentation for it.
> 
> 1. What are the ports on the back?  I have a printer port (serial or
> parallel?), two tape jacks, an RF video out, and a DB-9 port.

To identify the "printer port", you'll have to open up the computer.
The IIe has no built in parallel or serial ports.  They are provided
by I/O cards plugged into one of the slots.  You'll have to identify
the card that the connector comes from.  Many have an obvious name
printed on them, but third-party parallel and serial cards may be
anonymous.  If there is no visible name and part number on the card,
look for identification numbers on the larger chips on the board, and
post a message here.  I'm sure that any Apple II card can be
identified by someone on this newsgroup.

> What is the DB-9 port?  Is it a serial port, and can I use it to
> connect via null modem to my pc or amiga?

None of the above.  It is a joystick/paddle connector.  It provides
four analog inputs for a pair of joysticks (though two joysticks is
very rare), and three digital inputs for pushbuttons.  (Also +5V power
and ground.)

There is another game connector inside the computer (an empty 16-pin
socket near the top right corner of the motherboard).  It provides the
same signals as the connector on the back panel, plus four digital
outputs and a strobe (pulse) output.


The cassette in/out jacks are very rarely used in this day and age
(they don't exist on later Apple IIs).  Using a disk drive is vasty
preferable for saving and loading files.  A tape is useful for
emergency backup, but is very slow and clumsy to use.

> 2. Is there a Apple Basic manual online somewhere?

Probably not.  Applesoft BASIC was written by Microsoft, and is similar
to early Microsoft implementations.

Variable names are limited to two letters (additional letters are
ignored) and reserved words cannot be used as part of variable names.
Variable types are integer (%), real (no suffix) and string ($).
There is no single/double precision support.

Line numbers are required, and there is no support for named
subroutines.  Single expression functions are allowed, via DEF FN.
GOTO and GOSUB cannot use calculted destinations, but there is an ON
expresssion GOTO/GOSUB statement (go to one of a list of lines
according to the value of the expression).

There are several Apple II-specific features, particularly for dealing
with the graphics modes (low resolution and high resolution).  No disk
support is built into the language - it is added by ProDOS via PRINT
statements.  A disk command is issued by printing a Ctrl-D character
(CHR$(4)) followed by the command.  The usual method is to set up a
variable called D$ which is initialized to CHR$(4).

e.g.

10 D$=CHR$(4)
20 PRINT D$;"CATALOG"

> I don't have any comm software for this thing, and I want to write a
> quick file transfer routine to get me going enough to transfer
> something beter.

You'd be lucky to get any sophisticated protocol running in Applesoft
BASIC.  Parallel cards don't generally provide firmware support for
bidirectional data transfer (though the hardware may support it).  The
standard serial card for the Apple II (Super Serial Card) has no
buffering support in the firwmare, so you have to send characters
pretty slowly if you aren't using interrupts (impossible from BASIC).

What were you thinking of using as a protocol?

There isn't much point going into details until you can identify which
I/O cards you have in the computer.

> 3. The FAQ didn't mention what the advantages were for upgrading to an
> Enhanced IIe.  What are they?  Also, about how much does the kit cost?
> me by until I can download something better... :-)

The main advantage of an enhanced IIe is that a signficant proportion
of software requires one.  The majority of Apple II communications
programs, and many utilities and applications, expect a 65C02
microprocessor, the Mousetext character set, the revised interrupt
handler and the improved 80-column firmware, all of which are part of
the enhancement (four chips).

Many programs also expect 128k of memory.  The IIe has 64k built in,
and requires an extended 80-column card (64k RAM card) in the
auxiliary slot to upgrade it to 128k.  Larger memory cards (from third
party sources) can be used in this slot.  You can also put RAM cards in
the standard slots, but these can only be used as a RAM disk or
temporary storage by applications.  They don't provide the 64k
auxiliary memory.

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