RE: Random Characters

 
arcade comp

Best regards,
Ed Johnson
 

-----Original Message-----
From: owner-cbm-hackers@musoftware.de
[mailto:owner-cbm-hackers@musoftware.de] On Behalf Of MikeS
Sent: Monday, February 06, 2012 11:25 PM
To: cbm-hackers@musoftware.de
Subject: Re: Random Characters

Excellent! Congratulations; which version of the PLA did you get, arcade
comp or retro-donald??

m
----- Original Message -----
From: "Ed Johnson" <ejohnson.ed@gmail.com>
To: "'Rob Clarke'" <crock@clarke-family.org.uk>; <cbm-hackers@musoftware.de>
Sent: Monday, February 06, 2012 7:23 PM
Subject: RE: Random Characters


> Thanks for all the help. The new PLA arrived today.
> I performed the surgery on it and the patient is
> doing fine. It actually seems to have clearer video.
>
> Now to fix the sound...
>
> Best regards,
> Ed Johnson
>
>
> -----Original Message-----
> From: Rob Clarke [mailto:crock@clarke-family.org.uk]
> Sent: Sunday, January 29, 2012 10:10 AM
> To: cbm-hackers@musoftware.de
> Cc: Ed Johnson
> Subject: Re: Random Characters
>
> Some early boards do not have the commodore part number on the PLA. In
> this
> particular photo it's below the 6510 (cpu) and to the left of the
> 6581 (SID).
>
> If it is the PLA at fault, you can buy a new one here:
> http://www.arcadecomponents.com/catalog/item/3054735/8335676.htm or buy a
> modern replacement here :
>
http://retro-donald.de/sinchai-shop/index.php?main_page=product_info&cPath=3
> &products_id=16
>
<http://retro-donald.de/sinchai-shop/index.php?main_page=product_info&cPath=
> 3&products_id=16>
>
> rob
>
> On 29/01/2012 16:01, Ed Johnson wrote:
>> I don't see that chip. Can you identify it in this photo?
>>
>> http://upload.wikimedia.org/wikipedia/commons/8/86/C64motherboard.jpg
>>
>>
>> -----Original Message-----
>> From: owner-cbm-hackers@musoftware.de
>> [mailto:owner-cbm-hackers@musoftware.de] On Behalf Of Gerrit Heitsch
>> Sent: Sunday, January 29, 2012 8:56 AM
>> To: cbm-hackers@musoftware.de
>> Subject: Re: Random Characters
>>
>> On 01/29/2012 02:29 PM, Ed Johnson wrote:
>>> I have a C64 that displays random characters on the screen and locks
>>> up when powered on. Sometimes it powers on correctly but within
>>> seconds displays random characters and locks up. I bought it off eBay
>>> and it worked fine for about a week of heavy use but then this
>>> problem
>> started.
>>
>> The usual suspects in this case are the PLA (906114-01), the 74LS258,
>> the CIA that supplies the 2 extra address bits for the VIC and maybe the
> RAM.
>>
>> Also, if any of the chips I mentioned are in sockets, see if removing
>> them and putting them back in helps.
>>
>>    Gerrit
>>
>>
>>
>>
>>         Message was sent through the cbm-hackers mailing list
>>
>>
>>         Message was sent through the cbm-hackers mailing list
>
>
>
>       Message was sent through the cbm-hackers mailing list


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