Re: Need help with Apple II Plus

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

In article <1995Jul23.165621.1@spcvxb.spc.edu>,
 <5leitgeb_c@spcvxb.spc.edu> wrote:
>  
>           I just acquired an old Apple II Plus, and I need some information
> on it. First off, the machine does not power up, and I suspect it may be the
> power supply. Is it possible to still get replacement power supplies for
> this computer? Is there something I could substitute for the original
> supply?

Not new ones, but it should be possible to get replacement power
supplies from some resellers such as Alltech Electronics.

The IIe and II+ have electrically compatible power supplies, but the
IIe one is bigger, and might not mount properly in the II+ case.

You may be able to use a power supply from another source, as long as
it can provide sufficient currents on all four power rails.  The II+
power supply generates the following:

+5V at 2.5 amps
+12V at 1.5 amps (must be able to supply 2.5 amps for up to 2/3 of the time)
-5V at 250 milliamps
-12V at 250 milliamps

The 5V rail must be pretty close, but the other three are less
critical (+/- 0.2V should be OK).

>       Also, I am not that familiar with Apple computers, and I want to
> know about when the Apple II Plus was made.

The ][+ was made from about 1978 to 1982.  The IIe was designed to
replace the II+, and was released in 1983.

In effect, a IIe is an Apple II+ with built-in 16k language card,
built-in 80-column firmware and hardware support (all that is needed
is additional memory), support for an auxiliary 64k RAM space,
improved firmware and full keyboard.

> Can any IIe software run on the II plus?

In general, no.  Most software that says it requires a IIe will not
run on a II+.

There are bound to be some cases where the program claims that you
need a IIe, but it will work on a II+ with limitations.  For example:
any program that requires the Open-Apple and Solid-Apple keys could be
used on a II+ as long as you had a pair of paddles or joystick (button
0 is Open-Apple, button 1 is Solid-Apple), provided it doesn't depend
on other features of the IIe.

Any program that requires an "enhanced IIe" or a "128k IIe" (or an
"enhanced 128k IIe") will definitely not work on a standard II+, though
some programs that require a 64k enhanced IIe might work in a II+ that
had a ZIP CHIP, 65C02 or 65802 processor instead of the normal 6502.

> Since I also have access to Apple IIc software, is any of that
> compatible with the II Plus?

No.  The IIc can usually be regarded as an enhanced 128k IIe, with
built-in peripherals and some minor differences.  Software that
requires a IIc will usually work on a IIgs or enhanced 128k IIe, and
might work on a 64k IIe, but is unlikely to work on a II+.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand