Re: Two questions for all of you diehard Apple II fans.

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

Mark Piazza <piazza@servtech.com> wrote:

> OK, the first question: Is there such a memory card for the IIgs that allows
> one to use standard SIMM type memory chips?

8-bit (30-pin) SIMMs are supported by at least two cards: the MDIdeas
OctoRAM (I have one of these in my ROM 1 IIgs), and one version of a
card sold by Quality Computers, which was also sold by a third party.  I
forget its name.

The OctoRAM supports one, two, four or eight SIMMs, all of which must be
the same size (256KB or 1MB).  With eight SIMMs installed, it is not DMA
compatible.

The other card supports one, two or four 1MB SIMMs.

As far as the SIMMs go: parity is irrelevant, the SIMMs must support
RAS-before-CAS refresh, and some hybrid types may not work.  The speed
should be 120 ns or faster.  The safest bet is to use SIMMs that are
known to work in a Mac Plus or SE.

There is no card for the IIgs which supports 32-bit (72-pin) SIMMs.

> and secondly, is there any information on using the game port (the little
> white socket, not the 9pin d-shell (is there a difference?)) to control a
> robot of some sorts?  It probably could be done using the different strobe
> commands, right?

Well, the signal called "Strobe" doesn't exist on the IIgs (it is
present on the original ][ through to the enhanced //e - it generates a
low-going pulse for half a microsecond when location $C040 is accessed).

There are four annunciator outputs, which are TTL-level signals that can
be set ON or OFF individually.  Everything else is inputs: four analog
inputs, normally used for paddles or joysticks, and three digital inputs
(four on the IIgs) which are normally used for joystick buttons, and two
of them are in parallel with the Command and Option keys, which limits
their usefulness.  (The remaining pins are +5V, ground and unused.)

The D-9 connector on the back is connected in parallel with the internal
game port.  It provides the four analog inputs and three digital inputs,
power and ground, but no outputs.

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