Re: IIc+ accelerator

["william strutts" <wrstrutts1@home.com>]

Can you run your IIe at 4mhz then?

--
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William R. Strutts - wrstrutts1@home.com - Whatever!

C'est moi!  http://www.facelink.com/wrstrutts

Just hacking away...
"Mitchell Spector" <a_specto@alcor.concordia.ca> wrote in message
3b12eeca.31495763@newsflash.concordia.ca">news:3b12eeca.31495763@newsflash.concordia.ca...
> On 28 May 2001 10:23:57 -0700, aiiadict@hotmail.com (Rich J.) wrote:
>
> >Hi,
> >
> >I could open my IIc plus to figure this out, but it is packed away.
> >
> >How does the IIc+ accelerator work?  Is it all on the CPU chip, or
> >are there chips on the motherboard which help acceleration (slow down
> >for I/O, cycle stretch, etc) ?
>
>     It has the exact equivalent of a 4 MHz ZipChip. It was by no
> coincidence though, Apple licensed the technology from (then)
> Zip Technologies to use their patented acceleration technique
> within the IIc Plus. Technically it _is_ a Zip Chip inside.
>
>     Though instead of an actual (tall) 40-pin ZipChip however, Apple
> broke out the accelerator into separate components and incorporated it
> into the motherboard. It consists of an ASIC, 65C02-4, two 8K SRAMs
> (one for TAG and one for Data) and probably some other chip logic to
> make it all work. It's been several years since I've last opened my
> IIc Plus and had a look...
>
> >Can I pull the CPU from my IIc+ and accelerate an apple IIe?
>
>     No. You could pull the 4 MHz 65C02, but the IIe would just
> run it at a standard 1.024 MHz frequency (in fact most 65C02's
> I've come across in stock IIe's are rated for around 4 MHz and
> underclocked).
>
> Mitchell Spector
> a_specto@alcor.concordia.ca
>
>