Re: Apple IIc expansion options

["Charles Stephens" <charles_stephens@hotmail.com>]

There is always the SmartPort.

cfs


"David Empson" <dempson@actrix.gen.nz> wrote in message
1ei75j7.xwbq9s15lw2rkN%dempson@actrix.gen.nz">news:1ei75j7.xwbq9s15lw2rkN%dempson@actrix.gen.nz...
> **** **** <***@***.com> wrote:
>
> >     What are the expansion options available on the 2c?
>
> Nearly all expansion options are external.
>
> Applied Engineering did a memory expansion card which operates like the
> RamWorks (multi-bank auxiliary memory).  This plugs into the CPU and MMU
> sockets, and those chips then plug into the card.
>
> Later revisions of the IIc have a dedicated memory expansion slot, for
> Apple's IIc memory expansion card, which works like Apple's standard
> slot RAM card for the II+/IIe, i.e. a "slinky".  The motherboard
> contains all the firmware support - the card is almost purely RAM with
> very little support circuitry required (probably one ASIC to implement
> the "slinky" address latch).
>
> You can also use a Zip Chip or Rocket Chip to accelerate the CPU.
>
> The IIc+ has a modem slot, but I don't know if anything was ever made to
> go in it.  It ties into the slot 2 hardware (making use of the existing
> 6551 on the motherboard), and I expect the external modem port would be
> disconnected automatically if you plug in an internal modem.
>
> > I'm somewhat familiar with what can be done externally, and I realize
that
> > there are no internal slots. Are these slots totally absent from the
> > design, or are the sockets simply missing from the mainboard?
>
> The motherboard hardware emulates the slots, in that you have I/O
> devices and firmware which appear to be in slots 1-7 as far as the
> software is concerned.  Most of the physical slot signals are missing.
> For example, there are no IOSEL or IOSTROBE signals - the IIc uses a
> single ROM that is enabled for all locations in $C100-$FFFF.  (The
> "UniDisk" and later revisions also use bank switching to toggle the
> entire ROM space between two 15.75 KB banks, to allow for extra code
> like the SmartPort support and self-test.)
>
> The DEVSEL signals probably exist in some form, since there are I/O
> devices in the address space for slots 1, 2 and 6.
>
> --
> David Empson
> dempson@actrix.gen.nz
> Snail mail: P O Box 27-103, Wellington, New Zealand
>