Re: PET 2001 fix Part 3 - RAM/ROM board etc.

Slowly but surely, one step at a time...

Did you get a chance to test the four RAM chips in the video socket?

What you're describing is often caused by the I/O chips causing trouble when 
the system gets around to initializing them, but the PIAs are still out and 
you've tried replacing the 6522 with a known good one, correct?

Maybe try replacing all four 40-pin chips with the other set just to make 
sure? Maybe some problem with interrupts.

m

----- Original Message ----- 
From: "Philip Lord" <random6000@mac.com>
To: <cbm-hackers@musoftware.de>
Sent: Monday, May 16, 2011 12:03 AM
Subject: Re: PET 2001 fix Part 3 - RAM/ROM board etc.


>I found a small stack of DM74165's in my IC collection. I removed and 
>socketed B2 and replaced it with my DM74165.
> Character noise now all cleared up. Perfect! Ruud's program looks good and 
> clear now. Still won't start from BASIC 2 set/
>
> Phil
>
>
> On May 16, 2011, at 11:00 AM, Philip Lord wrote:
>
>> One thing that Ruud's program confirms is that the left most column 1 and 
>> 2 are repeating:
>> See video at the bottom of the page here:
>>
>> http://web.me.com/lord_philip/other_computers/20012.html
>>
>> Phil
>>
>> On May 16, 2011, at 10:30 AM, Philip Lord wrote:
>>
>>> Thanks Ruud,
>>> I tried out your image in a 2532 at H4.
>>>
>>> It displays a set of all the characters, then displays the inverse set, 
>>> and repeats. I'm assuming this is correct?
>>>
>>> I still have the pixel flicker, and character distortion. I will 
>>> hopefully be able to get a 74LS165 today, and swap it out sometime soon.
>>>
>>> Thanks again
>>>
>>> Phil
>>>
>>>
>>>
>>> On May 16, 2011, at 5:42 AM, Ruud@Baltissen.org wrote:
>>>
>>>> Hallo Philip,
>>>>
>>>>
>>>>> Any chance you could email me a .bin file of that which I can burn
>>>>> to a EPROM.
>>>>
>>>>
>>>> .ba $F000
>>>> Reset
>>>> sei
>>>> cld
>>>>
>>>> ;**  Fill screen with values 0..$FF
>>>> ldx #0
>>>> L0
>>>> txa
>>>> sta $8000,X
>>>> sta $8100,X
>>>> sta $8200,X
>>>> sta $8300,X
>>>> inx
>>>> bne L0
>>>> L1
>>>> beq L1
>>>>
>>>>
>>>> IRQ
>>>> NMI
>>>> rti
>>>>
>>>> .ba $FFFA
>>>> .wo NMI
>>>> .wo Reset
>>>> .wo IRQ
>>>> .en
>>>>
>>>> BIN is attached.
>>>>
>>>>
>>>>> After burning some BASIC 2 EPROMs, it seems I'm now getting a reset as 
>>>>> the
>>>>> screen fills with garbage than after about 1/2 a second goes 
>>>>> completely
>>>>> blank...I think this is progress.
>>>>
>>>> The blanking is done by the CPU so this is indeed a progress.
>>>>
>>>>
>>>> --
>>>>  ___
>>>> / __|__
>>>> / /  |_/     Groetjes, Ruud Baltissen
>>>> \ \__|_\
>>>> \___|       http://Ruud.C64.org
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> The following section of this message contains a file attachment
>>>> prepared for transmission using the Internet MIME message format.
>>>> If you are using Pegasus Mail, or any other MIME-compliant system,
>>>> you should be able to save it or view it from within your mailer.
>>>> If you cannot, please ask your system administrator for assistance.
>>>>
>>>> ---- File information -----------
>>>>   File:  KERNAL2.BIN
>>>>   Date:  15 May 2011, 22:37
>>>>   Size:  4096 bytes.
>>>>   Type:  Unknown
>>>> <KERNAL2.BIN>
>>>
>>>
>>>      Message was sent through the cbm-hackers mailing list
>>
>>
>>       Message was sent through the cbm-hackers mailing list
>
>
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