//c+ Overclock Project

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//c+ Overclock Project

I sucessfully overclocled my Apple //c+ to 8 Mhz by doing a simple oscilator swap. I replaced the 16 Mhz osc with a 32 Mhz osc. I plan on in the future to replace the stock CPU and the TAG and DATA SRAM.. I plan on puting in a 56 Mhz osc or one as close to it as I can find.

Merry Christmas

Mark Frischknecht

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nice.

About all I can say. Sweet. Ok... maybe not all I can say.

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Interesting project

This sounds like a very interesting project. Please keep us informed of your progress/or problems. (Pics would be nice.)

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Well Jameco in sending me the

Well Jameco in sending me the correct SRAM.
And I have pictures! much hasnt changed just the OSC
Warning Large Picture around 800kb

http://www.appleiiguy.net/images/iicplusmod01.JPG

The Oscilator With FOX on it is the new 32 Mhz Osc

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overclocking

Absolutely beautiful! I have just one question, is there any problems in using the serial outputs/inputs at the overclocked speed? ie- is 1200 still 1200?

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Tested from my //c+ to my PC

Tested the serial ports by trasferring a text file and a small shrinkit archive from my PC to the //c+ and back. I used Proterm on the Apple side and Hyperterminal on the X86 side.
BPS Rate : What happend.
100 : Transferd fine
300 : Transferd fine
1200 : Transferd fine
2400 : Transferd fine
4800 : Transferd fine
9600 : Transferd fine
19200 : Transferd fine

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Got some better pics up. Caut
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IIc+ dual clocking - best of both worlds

Well, thanks to technerd, I started another project. But this one I finished. Overclocking has always peeked my curiosity, making something do something faster than it was originally designed to do. After technerd posted this topic, I bought an Apple IIc+ just to tinker with. Yes, You can swap out cyrstals and make it go faster, but you can't play the old games with a machine like this, unless you are really, really, really good. So here is where my project started. Instead of cracking the case and swaping crystal every time you wanted to do something diferent on the computer, I added a switch.

A switch you say? What does the switch do? Well I decided to install two crystals in my IIc+ and switch between them, so I would not have to crack the case open, and still have the best of both worlds. I frst created a proto board and installed it. After several weeks, I had decided this was perfect for me, and I started to design a board that would fit in this space constrained system.

Fitting it in my system with a memory expansion board was tight. From both angles.

So, my many thanks to technerd for sharing his project with me. I now can run my Apple IIc+ at 1Mhz, 4Mhz, and 8Mhz, with the flip of a switch.

-James Littlejohn
http://8bitsystem.com

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Very nice! I wonder if you ca

Very nice! I wonder if you can overclock a plain Apple //c?

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IIc overclocking

The only way I know of is with a Zipchip. I have a IIc with an 8Mhz Zip chip in it.

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now all you have to do is...

Put it in the applecrate and replicate it with a lot more systems like it. man, that thing would speed....

Btw, even with a Hard drive that would be available for the Apple ][ (or the 32MB Compactflash card) would it be possible to engineer a unix on a card that the system could have the rom written to have the machine access the card to boot from it? Unix on an Apple ][ would be sooo cool! (better yet, Puppy Linux for the 6502!)

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Unix iirc needs a proper mmu.

Unix iirc needs a proper mmu. Sadly the Apple // line doesn't have one

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IIc+ Mod

I have been asked been asked by several people in this forum, and others, for more detailed info. So, I have set up a step, by step guide in how I did this.

Apple IIc+ Mod

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Re: //c+ Overclock Project

Sorry to resurrect an old thread.

I tried to overclock my IIc+ this evening. It worked and speed was fast with a 34MHz crystal (8.5 MHz) but it only worked with the external 5.25" drive. Any attempted access to the 3.5" drive locked up the machine. I put the original crystal back in and all was fine. Strange that it had only that effect, but perhaps it overclocks the ASIC that controls the floppy drive as well, and mine doesn't like that.

-Pete

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Re: //c+ Overclock Project

Possibly you're pushing the limit a little too closely. Maybe scaling back to 7.5 or 8mhz would solve the problem. The hardware varies in how fast you can push it. About 10 years or so ago I overclocked two IIc+. One went to 10mhz and the other wouldn't go higher than 8mhz reliably.

Wayne

rittwage wrote:
Sorry to resurrect an old thread.

I tried to overclock my IIc+ this evening. It worked and speed was fast with a 34MHz crystal (8.5 MHz) but it only worked with the external 5.25" drive. Any attempted access to the 3.5" drive locked up the machine. I put the original crystal back in and all was fine. Strange that it had only that effect, but perhaps it overclocks the ASIC that controls the floppy drive as well, and mine doesn't like that.

-Pete

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Re: //c+ Overclock Project

I did some in-depth research on this back in 2008.
Here is a link to my findings.
http://a2central.com/1586/overclocking-the-apple-iic-plus-just-got-easier/

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Re: //c+ Overclock Project

I did find you page- thanks for that.

Mine is an “A” board with the NCR ASIC. All of my disks are 5.25" so I didn't really notice a problem until a day or so later when I tried to transfer a disk to the 3.5" with ADT.

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Re: //c+ Overclock Project

I appreciate the technical skill involved in what you have done, but, if I may be so bold as to ask, why do it? Do games run better? You say you can transfer faster but does this make any real difference to anything? Just curious.

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