Re: ZipGS and the annunciator ports...any connection?

[scott@alfter.DIESPAMMERSDIE.us (Scott Alfter)]

In article <R7udnS5IW-xBpHrbnZ2dnUVZ_ruqnZ2d@comcast.com>,
Michael J. Mahon <mjmahon@aol.com> wrote:
>Scott Alfter wrote:
>> My 1-Wire routines need to run at 1 MHz, so slowing down to that speed
>> involves switching off the ZipGS (to go from 8 MHz to 2.8) with its CDA and
>> then going into the Control Panel CDA to slow down from 2.8 MHz to 1 MHz.
>
>Boy, slowing down for a while is a lot easier on a //e!

That was a brain fart on my part...just selecting "normal" instead of "fast"
is enough.

>Just a quick reference to $C0E8 (slot 6 drive off), will slow down
>an accelwrator for about 50 milliseconds--usually enough to get done
>what needs to be done.

Hmm...hadn't considered that.  50 ms would definitely be long enough (the
longest 1-Wire transaction is a reset, and that's only about 500 �s IIRC).

>> If I use AN0 and AN1 on a ZipGS-equipped machine to control other hardware,
>> is that going to have some effect on the ZipGS's operation?  Since all of
>> the ZipGS's configuration is done through software, was the means by which
>> it's configured ever documented by anybody?  If the accelerator kicks in
>> while software is communicating with 1-Wire devices, it'll produce invalid
>> results, so I need to make sure that doesn't happen.
>
>The Zip probably requires a secret dance on a softswitch to "unlock",
>so you're unlikely to disturb it.  On the other hand, software that
>talks to the Zip may disturb your hardware.

I know it bangs on AN1 for some reason...haven't tried seeing if it does
anything to AN0.  The 1-Wire interface I built pulls the bus high with a
resistor.  When AN0 is off, the output of a 74HCT126 buffer is in its
high-impedance state.  When AN0 is on, the '126 drives the bus low.

Speaking of 1-Wire interfaces and the Apple II, I found my stash of PC
boards I had made up a couple or three years ago.  If anybody wants one to
play with, send me email.  They're bare boards; you would need to add a
74HCT126 (SO-14 package), a bypass capacitor, one or two resistors, a 16-pin
wire-wrap DIP socket, and a 3-pin header for a minimal configuration.  A
PN2222, a 1N4004, a resistor, and some different headers (5-pin and 1-pin)
would add the relay controller; a DS2417, a bypass capacitor, and a
32.768-kHz crystal would give you a real-time clock on the 1-Wire bus. 
(Unfortunately, I forgot to add battery backup to the design, so the clock
resets when you kill the power.  I also haven't gotten around to writing a
ProDOS clock driver for it.)

I think $5 would cover what I paid to have the boards made and would cover
mail).  IIRC, I have six or seven that I could let go.

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