PAK issues

Problems with your machine in general.
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pakman
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Re: PAK issues

Post by pakman »

Next: Remove the U5 jumper wire, and assemble U5 instead. Try to boot.
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PhilC
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Re: PAK issues

Post by PhilC »

with U5 inserted and the wire removed from U1 also it does boot to desktop
If it ain't broke, test it to Destruction.
pakman
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Re: PAK issues

Post by pakman »

Ok, add GAL U4 and try to boot
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PhilC
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Re: PAK issues

Post by PhilC »

It gets to desktop with U4 inserted as well but wont boot the floppy image I had on Gotek but one step at a time :)
If it ain't broke, test it to Destruction.
pakman
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Joined: Fri Feb 16, 2018 10:04 pm

Re: PAK issues

Post by pakman »

That's weird. Check the voltage at U4 pin13, should be high. Then all outputs of U4 should be tri-stated, essentially the same as if there were no U4 at all.
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PhilC
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Re: PAK issues

Post by PhilC »

I have 4.48v on U4 pin 13
If it ain't broke, test it to Destruction.
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PhilC
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Re: PAK issues

Post by PhilC »

I've also put u2 back in and it boots if that helps

Edit:

In fact it ill boot with all 5 Gals inserted
If it ain't broke, test it to Destruction.
pakman
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Joined: Fri Feb 16, 2018 10:04 pm

Re: PAK issues

Post by pakman »

Let's fix U4 first. Get another GAL (not the U4 you are using right now), program the P4 JEDEC, and try again to boot.
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PhilC
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Re: PAK issues

Post by PhilC »

Ok, just U3, U$ and U5 inserted and it now doesn't boot
If it ain't broke, test it to Destruction.
pakman
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Re: PAK issues

Post by pakman »

The very same U4 as before? Or a new U4?
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