Re: How to tell if a IIc has a zipchip

[mjmahon@aol.com (Michael J. Mahon)]

Beverly wrote:

>I don't know much about this subject, but in my extensive list of Peeks for
>AppleWorks, I have the folllowing:
>
>Peek $C074  Speed of Rocketchip or Transwarp  0=Fast  1=Slow
>
>Since this is a hardware peek, it should work without AppleWorks running.
>Perhaps others could look this up and give more information before you try
>it. 
>I do not know if it applies to a Zip.  I remember seeing a //c running
>AppleWorks with a zip chip in it and was quite amazed. I never owned one
>myself.

This PEEK doesn't work with a Zop Chip.

The Zip Chip was designed to be essentially transparent to the Apple
environment, so you have to do a little "dance" with multiple consecutive
(assembly language) address references to get it to map its soft switches.

Since the Zip Chip can treat the speaker address as a "slow down"
signal, the beep can sound quite normal.  But I believe that the normal
default state entered upon RESET is with no slowdown on speaker
reference, so the normal "beep" is a high-pitched "chirp".

The completely foolproof way to tell is run a FOR I=1 to 1000:NEXT
loop, perhaps with a PRINT CHR$(7) following it, and loop.  The
speed of the beeps makes the time delay of the FOR loop audible
and can be easily calibrated to system speed.

-michael

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