Re: Apple IIc Plus questions

[sbeattie@helios.augustana.edu (Shawn T. Beattie)]

spec@vax2.concordia.ca (Mitchell Spector) writes:

>   I've just recently added an Apple IIc Plus to my collection (finally
>have one of each Apple II model, minus a few variants :) and have a few
>questions about the machine.

Congrats...I made the same milestone but now am starting to part with some
models as part of a twelve-step Appleholics Anonymous program. ;)

>- Is the 34-pin memory expansion connector on the motherboard compatible
>  with the one found on the late model (ROM 3 and 4) Apple IIc? It looks
>  the same, expect for a small set of male-pins beside it (separate from
>  the main connector and not parallel to it). 

Hmm..the IIc Tech Ref, p.402 sez:

"Due to the faster clock rate used in the Apple IIc Plus computer, the 
memory expansion card manufactured by Apple Computer, Inc. for use in
the memory expansion Apple IIc does not work in the Apple IIc Plus computer.
To add a memory expansion card to the Apple IIc Plus, you must purcase a 
card made by another manufacturer specifically for the Apple IIc Plus.  
However, the RAM chips on an Apple Memory Expansion Card may be used on a 
memory expansion card in the Apple IIc Plus computer."

The seven pin connector you referred to (J14), which looks just like the 
Apple IIc Plus internal modem connector, is  "an additional internal 
expansion connector to provide additional signals for memory expansion cards"
(p. 405, Apple IIc Tech Ref)

>- Is the system error "bell" supposed to sound different from other 8-bit
>  Apple II's? My IIc+ makes a lower pitched "beep" when turned on. Is this
>  normal or was it just changed as it was on the IIgs?

It should be similar to the other IIc's, a 0.1 second 1kHz tone.  I think
I noticed it was slightly different also, possibly due to slightly different
timing?

>- Is the original character generator/Video ROM the same one found in
>  an Enhanced IIe? The chip installed is identical, even has the same
>  part number (342-0265-A) and number of pins. I'm curious if someone
>  didn't swap chips, since the socket has more pins than the chip and 
>  the part number silked-laced on the motherboard is different. As well, 
>  the "running man" character is still mapped to 'F' and 'G'.

I have the same character generator in my IIc+. Apple must have changed
its mind at the last minute.

>  ie - A game like Atari's Ms. Pac-Man. The music at the start is not
>  distorted (plays as if it were 1 MHz) and as I move through the maze
>  the sound and animation continue as normal. However, if I stop moving
>  and sit in a corner, all of a sudden it jumps into 4 MHz and the ghosts
>  start whizzing around. As soon as I move again, it jumps back to 1 MHz.
>  This seems to be the case with all software, it mostly runs at 'Normal'
>  speed and every so often gives short bursts of speed (almost like it's 
>  struggling to accelerate!). Is this _normal_ or is something wrong?
>  I've never seen another IIc Plus or Zip Chip in operation, I'm only
>  familiar with the IIgs and it's 2.6 MHz acceleration (or faster) which 
>  is a _constant_. 

The IIgs is not using a cache to speed up, whereas the IIc+ is.  From p. 329
of ye olde IIc Tech Ref:

"When the accelerator is enabled and the CPU is processing data from the 
cache RAM, the system runs at its fastest speed.  When the CPU is 
processing data from system RAM, or when the acelerator is disabled, the 
CGGA (cache glue gate array) synchronizes the CPU to the rest of the 
system and the Apple IIc Plus runs at the same speed as other Apple IIc 
computers."

So when you're not moving Ms. Pac Man, the code to move the ghosts around 
is cached and you're zipping along at 4 MhZ.  When you start moving around
you must be exceeding the 8K data cache or something else is forcing the
CCGA to slow the system down to 1.023 MhZ.

>- I noticed I have to hold down the Open-Apple key longer when doing an
>  Apple-Control-Reset to warm boot (otherwise the machine just sees it
>  as a Control-Reset). My IIe's, IIc's, and IIgs's are not like this,
>  is this normal? Is it a side-affect of the built-in 3.5 drive?

I have noticed this also.  The IIc Tech Ref (p.87) says "On all Apple IIc 
family computers but the original Apple IIc, you must hold down the 
Command key (Open Apple on older Apple IIc computers) down until the 
internal drive starts to spin" for a forced cold reset.

>- How many external drives can be connected to it's Smartport? I assume
>  one Apple 3.5 and two Apple 5.25 (or a couple of UniDisk 3.5's).

The IIc+ supports three external drives: any combination of up to two
5.25" drives, up to three UniDisk 3.5 drives, and one Apple 3.5 drive.
The Apple 3.5 drive comes first, then Unidisk 3.5 drives, then any 5.25 
drives.  IIc Tech Ref p.86 also says "The hardware and firmware of the 
Apple IIc Plus computer can support up to five disk drives, but the power 
supply supports only four".  


-Shawn