Apple //c garbage screen?

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NordicSnow's picture
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Apple //c garbage screen?

Hello!

On the //c I'm restoring, I'm getting a garbage screen that flashes different characters. On the bottom of the screen, the words "Check Disk Drive" are clearly visable. Amy ideas on what's wrong with it? Sorry if it's a stupid question, I'm kinda new at this.

Thanks!
~Zeke

gsmcten's picture
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Re: Apple //c garbage screen?

Do you happen to have any disks?

Steven Smile

NordicSnow's picture
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Re: Apple //c garbage screen?

Not for an Apple II, no.

~Zeke

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Re: Apple //c garbage screen?

Hello Zeke,

welcome to the board....

maybe it´s a good idea to take first some look at the basic manuals and
download some additional documentation ......
manuals and documentation is availiable for download at:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20II/Apple%20IIc/Manuals/

and to get access to the required disks for use at the IIc:
http://adtpro.sourceforge.net/

and the demanded diskimages for transfer to the Apple IIc can be found at:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20II/Apple%20IIc/Disk%20Images/
and at:
http://mirrors.apple2.org.za/ftp.apple.asimov.net/images/

sincerely
speedyG

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Re: Apple //c garbage screen?

If you have garbage characters randomly on the screen, most likely will be bad memory. Hold both Apple keys-ctrl-reset and will go into self check mode. At the end it should give you a code of the bad ram location. If your //c is a ROM 255 you will only get colors on the self test, and may need an ROM upgrade.
Read more in the Apple2FAQ:
http://www.apple2faq.com/knowledgebase/identifying-fixing-defective-ram-apple-iic-rom-255/

Hope this helps.

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Re: Apple //c garbage screen?

http://giphy.com/gifs/3o7qE055F3MWYteKoo

This is a gif of what's happening to it. Pressing both Apple keys +control and reset just made the computer beep, and made the disk drive chunk and then sent me back here again.

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Re: Apple //c garbage screen?

That looks different of what I've seen. Have you opened the computer and reseat the chips? Clean a little the motherboard? Check all contacts (drive, keyboard, etc) It may be something simple.

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Re: Apple //c garbage screen?

This garbage pattern is similar to what I experienced when I switched on my Apple //c without a keyboard encoder chip (for science!).

So it could be a bad keyboard encoder, or bad RAM.

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Re: Apple //c garbage screen?

That seems like a likely culprit, considering how flakey the keyboard is when pressing reset. Is there any way I can source a new "AY-5-3600-PRO" chip?

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Re: Apple //c garbage screen?

Keep in mind that a bad reset key could just be dirty contacts.

I've just been having the same discussions after replacing mine. My encoder was soldered to the logic board, so the actual transplant isn't as easy as one may expect.

I've taken a gamble and bought from this eBay seller: http://www.ebay.com.au/itm/321114416979?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

If I had spare cash I think I would have preferred to buy a spare //c or //e logic board, the value for money is a little better than just buying single chips when needed.

I would have tried to scavenge from other computers but I'm not sure where else it is used, possibly on some of the other early micros but I don't know enough about it.

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Re: Apple //c garbage screen?

I ordered the eBay chip, but shipping is going to take a while. I'll update once I get it installed.

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Re: Apple //c garbage screen?

This is the mother of all necros, but getting the chip was a bit harder than I thought. I had it shipped to my parents and finally got it installed today.

The garbage screen is gone, replaced by "Apple //c" and "Check Disk Drive" (although it will not recognize my diagnostic disk).
If i open a BASIC prompt, all of the keys are not correct (typing S will appear as an O, typing D will appear as E, and so on). Maybe the eBay chip is not a correct part?

EDIT: So thats what the keyboard button does. I'm dumb xD

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