Apple IIc + accelerate how to? [message #265340] |
Tue, 26 August 2014 18:16 |
oz390gta
Messages: 71 Registered: March 2013
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I know that one of the sessions at Kansasfest this year was James Littlejohn's Accelerating the Apple IIc+. I now have a IIc+ and want to have a go at this but can't find the instructions anywhere. I have confirmed I have the Model "A" logic board with NCR ASIC so I should be good to go.
A video of the Kansasfest session itself would be even better.
ctb
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Re: Apple IIc + accelerate how to? [message #265344 is a reply to message #265340] |
Tue, 26 August 2014 20:07 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
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ctb <oz390gta@gmail.com> wrote:
> I know that one of the sessions at Kansasfest this year was James
> Littlejohn's Accelerating the Apple IIc+. I now have a IIc+ and want to
> have a go at this but can't find the instructions anywhere. I have
> confirmed I have the Model "A" logic board with NCR ASIC so I should be good to go.
>
> A video of the Kansasfest session itself would be even better.
>
>
> ctb
To cut to the chase, it requires only replacing the 16MHz oscillator with a
32MHz oscillator (to get the 65C02 to 8MHz).
It's also a good time to add a machined pin socket for the oscillator, to
allow easier experimentation. (Some will go to 10MHz reliably.)
--
-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon
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Re: Apple IIc + accelerate how to? [message #265350 is a reply to message #265344] |
Wed, 27 August 2014 00:02 |
oz390gta
Messages: 71 Registered: March 2013
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On Wednesday, August 27, 2014 10:07:17 AM UTC+10, Michael J. Mahon wrote:
>
>> I know that one of the sessions at Kansasfest this year was James
>
>> Littlejohn's Accelerating the Apple IIc+. I now have a IIc+ and want to
>
>> have a go at this but can't find the instructions anywhere. I have
>
>> confirmed I have the Model "A" logic board with NCR ASIC so I should be good to go.
>
>>
>
>> A video of the Kansasfest session itself would be even better.
>
>>
>
>>
>
>> ctb
>
>
>
> To cut to the chase, it requires only replacing the 16MHz oscillator with a
>
> 32MHz oscillator (to get the 65C02 to 8MHz).
>
>
>
> It's also a good time to add a machined pin socket for the oscillator, to
>
> allow easier experimentation. (Some will go to 10MHz reliably.)
>
> --
>
> -michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon
Where do I find the oscillator on the logic board and what type do I need to replace it with?
ctb
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Re: Apple IIc + accelerate how to? [message #265351 is a reply to message #265344] |
Wed, 27 August 2014 00:05 |
mdj
Messages: 301 Registered: December 2012
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On Wednesday, 27 August 2014 10:07:17 UTC+10, Michael J. Mahon wrote:
> To cut to the chase, it requires only replacing the 16MHz oscillator with a
>
> 32MHz oscillator (to get the 65C02 to 8MHz).
Considering all the semiconductor components are of sufficient specification for at least 8Mhz operation, one wonders whether anybody at Apple did some synthetic benchmarks against the 8Mhz 68k platform the affordable Macs were using at the time.
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Re: Apple IIc + accelerate how to? [message #265377 is a reply to message #265351] |
Wed, 27 August 2014 11:11 |
Sean Fahey
Messages: 400 Registered: October 2012
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On Tuesday, August 26, 2014 11:05:06 PM UTC-5, mdj wrote:
>>>
Considering all the semiconductor components are of sufficient specification for at least 8Mhz operation, one wonders whether anybody at Apple did some synthetic benchmarks against the 8Mhz 68k platform the affordable Macs were using at the time.
<<<
Some boards will only do 6MHz.. so in addition to the machine pin socket, I'd recommend picking up a 24, 32 and 40MHz oscillators - it's not to much of an expense to have them all on hand for testing.
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Re: Apple IIc + accelerate how to? [message #265378 is a reply to message #265377] |
Wed, 27 August 2014 11:32 |
STYNX
Messages: 453 Registered: October 2012
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On Wednesday, August 27, 2014 5:11:24 PM UTC+2, Sean Fahey wrote:
> Some boards will only do 6MHz.. so in addition to the machine pin socket, I'd recommend picking up a 24, 32 and 40MHz oscillators - it's not to much of an expense to have them all on hand for testing.
Mine _only_ does 4 or 8 mhz. And 8mhz _only_ works with a 'special' one of several different crystals i tested. What makes it special? I don't know, they were all 32mhz 5V!
Even if you 2c+ des not work with the crystal you try, it might work with another...
-Jonas
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Re: Apple IIc + accelerate how to? [message #265393 is a reply to message #265378] |
Wed, 27 August 2014 12:42 |
Patrick Schaefer
Messages: 67 Registered: October 2012
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Am 27.08.2014 17:32 schrieb STYNX:
> Mine _only_ does 4 or 8 mhz. And 8mhz _only_ works with a 'special' one
> of several different crystals i tested. What makes it special? I don't
> know, they were all 32mhz 5V!
Check its output level (with an ocilloscope). Maybe a 4k7 pullup
resistor needs to be added to give full output swing.
Patrick
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Re: Apple IIc + accelerate how to? [message #265395 is a reply to message #265393] |
Wed, 27 August 2014 13:30 |
STYNX
Messages: 453 Registered: October 2012
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On Wednesday, August 27, 2014 6:42:06 PM UTC+2, Patrick Schaefer wrote:
> Check its output level (with an ocilloscope). Maybe a 4k7 pullup
> resistor needs to be added to give full output swing.
> Patrick
THAT is a very good advice. I know that i have used this 'patch' on a buggy Transwarp once. I have totally forgotten about that hack. I will try this (sometime) and post the results then.
-Jonas
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Re: Apple IIc + accelerate how to? [message #265423 is a reply to message #265351] |
Wed, 27 August 2014 19:21 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
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mdj wrote:
> On Wednesday, 27 August 2014 10:07:17 UTC+10, Michael J. Mahon wrote:
>
>
>> To cut to the chase, it requires only replacing the 16MHz oscillator with a
>>
>> 32MHz oscillator (to get the 65C02 to 8MHz).
>
>
> Considering all the semiconductor components are of sufficient specification for at least 8Mhz operation, one wonders whether anybody at Apple did some synthetic benchmarks against the 8Mhz 68k platform the affordable Macs were using at the time.
Interesting speculation.
All the early IIc+'s will work at 8MHz (at least).
The later production runs substituted another manufacturer for the ASIC
and slightly slower SRAMs, so maybe it was designed with margin for
8MHz, but after they decided to keep it at 4MHz, they saved a little on
parts...
--
-michael
NadaNet 3.1 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."
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Re: Apple IIc + accelerate how to? [message #265424 is a reply to message #265395] |
Wed, 27 August 2014 19:23 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
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STYNX wrote:
> On Wednesday, August 27, 2014 6:42:06 PM UTC+2, Patrick Schaefer wrote:
>
>> Check its output level (with an ocilloscope). Maybe a 4k7 pullup
>> resistor needs to be added to give full output swing.
>> Patrick
>
>
> THAT is a very good advice. I know that i have used this 'patch' on a buggy Transwarp once. I have totally forgotten about that hack. I will try this (sometime) and post the results then.
>
> -Jonas
I found that only one of my (various) 32MHz oscillators worked, too, so
I'll be very interested in your results!
I'd like both my IIc+'s to be IIc++'s. ;-)
--
-michael
NadaNet 3.1 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."
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Re: Apple IIc + accelerate how to? [message #265696 is a reply to message #265424] |
Sat, 30 August 2014 02:44 |
STYNX
Messages: 453 Registered: October 2012
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On Thursday, August 28, 2014 1:23:05 AM UTC+2, Michael J. Mahon wrote:
> I found that only one of my (various) 32MHz oscillators worked, too, so
>
> I'll be very interested in your results!
Results: With the mod all Oscillators up to 32mhz now seem to work, nothing above (not even 33mhz). I had already replaced the SRAM with 35ns parts as well as a the 74F00 (below the ASIC) for a 74AS00.
8Mhz or less it is...
-Jonas
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Re: Apple IIc + accelerate how to? [message #265795 is a reply to message #265696] |
Sun, 31 August 2014 00:11 |
Michael J. Mahon
Messages: 1767 Registered: October 2012
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STYNX <Jonas.Groenhagen@gmx.de> wrote:
> On Thursday, August 28, 2014 1:23:05 AM UTC+2, Michael J. Mahon wrote:
>> I found that only one of my (various) 32MHz oscillators worked, too, so
>>
>> I'll be very interested in your results!
>
> Results: With the mod all Oscillators up to 32mhz now seem to work,
> nothing above (not even 33mhz). I had already replaced the SRAM with 35ns
> parts as well as a the 74F00 (below the ASIC) for a 74AS00.
>
> 8Mhz or less it is...
>
> -Jonas
Cool! I'll have to try adding the pullup!
--
-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon
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Re: Apple IIc + accelerate how to? [message #265805 is a reply to message #265696] |
Sun, 31 August 2014 01:59 |
Sean Fahey
Messages: 400 Registered: October 2012
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On Saturday, August 30, 2014 1:44:50 AM UTC-5, STYNX wrote:
> Results: With the mod all Oscillators up to 32mhz now seem to work, nothing above (not even 33mhz). I had already replaced the SRAM with 35ns parts as well as a the 74F00 (below the ASIC) for a 74AS00.
>
Jonas, where did you get your RAM?
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Re: Apple IIc + accelerate how to? [message #265810 is a reply to message #265805] |
Sun, 31 August 2014 03:36 |
STYNX
Messages: 453 Registered: October 2012
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On Sunday, August 31, 2014 7:59:47 AM UTC+2, Sean Fahey wrote:
> Jonas, where did you get your RAM?
I got them from Doug Pendleton when he sold all the stuff that was left. I got 7 ZIP GSX with loads of SRAM and other goodies. I have repaired 4 of the ZIP-Cards and sent 2 working ones back to him... that was the deal.
I still have several wide body 8k and 32k 70ns, 55ns, 35ns and 30ns. These are very hard to get by...
But you can mod the common 25ns/20ns/15ns 8k cache chips by soldering them onto a wide DIP socket. Worked for me in the past.
-Jonas
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