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Type: Posts; User: nrg13

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    I have read a little more on the timing circuit...

    I have read a little more on the timing circuit of the Apple II, within the book "Understanding the Apple II", available at archive.org.

    There is a paragraph:



    So perhaps slight variations...
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    So... Playing around with the trigger levels on...

    So... Playing around with the trigger levels on my scope made the issue go away with the "noise" on the clock signals.

    I can now see a clean 1MHz at the CPU, and also a good sync signal. However,...
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    https://photos.app.goo.gl/nyMWijwVXAM49RLc8 ...

    https://photos.app.goo.gl/nyMWijwVXAM49RLc8

    Here is the Pin 7 signal - I think I see the same echo/shadowing as I do on the 1MHz clock.

    As an aside, I checked the 2MHz clock at Pin 4 of D2 -...
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    Powered on with good ROM F8 installed, checked...

    Powered on with good ROM F8 installed, checked the following:

    Pin 2 /RDY = High
    Pin 4 /IRQ = High
    Pin 6 /NMI = High
    Pin 7 /SYNC = Pulsing
    Pin 40 /RESET = High
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    No worries at all - thankyou ever so much for...

    No worries at all - thankyou ever so much for your time in any case, I will follow the steps outlined here - the symptoms are fairly similar:...
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    Can nobody assist? Is the 1MHz signal meant to...

    Can nobody assist? Is the 1MHz signal meant to have that "echo" I am seeing?

    I am using the composite connector as the ground if this makes a difference?
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    Europlus - Strange Timing Issue

    Hello all.

    I have been working for some weeks on an Apple II Europlus I picked up from eBay.

    The machine has never booted to the Apple ][ screen correctly - it has only ever shown variations of...
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    I asked the same question over here:...

    I asked the same question over here: https://www.applefritter.com/content/apple-iie-pal-does-not-boot

    and have made some solid progress.

    Thanks for the reply!
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    Apple IIe - International PAL

    Hello all :)

    I have an Apple IIe - it's the international PAL version, which has made diagnosing the issue with it a little tricky, as all the schematics and troubleshooting info seems to be for...
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    OK - I looked the machines over last night in...

    OK - I looked the machines over last night in preperation for sale. Sadly the magic smoke escaped from the Sirius - so that is unlikely to be sold.

    The PET also seems to be suffering from some...
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    All, These machines are in the UK - the...

    All,

    These machines are in the UK - the pictures above aren't of the units themselves - I will have these in short order, along with videos of the systems working.

    Thanks for all your help!...
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    Value of CBM machines?

    A friend of mine has a number of CBM/CBM compatable computers that he would like to sell. Can anyone have a guess at the value? I've scoured eBay etc for previously sold items but they seem so rare...
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