Re: PET 2001 Fix....WAS: Will pay good money for NON working PET 2001 motherboard.

From: Philip Lord <random6000_at_mac.com>
Date: Sun, 22 Nov 2009 10:47:23 +0900
Message-id: <AAD4D091-A859-4AE1-A5CE-F1AFADC5565C@mac.com>
Hi again,
I just wanted to say a big thanks for everyones help, and to apologize  
for being such a dumbass for not being able to fix the board.

Anyway, Ethan has the boards now, and has kindly offered to take a  
look at the problem for me. Thanks again Ethan.

Phil


On Nov 10, 2009, at 3:16 PM, William Levak wrote:

> On Mon, 9 Nov 2009, Philip Lord wrote:
>
>> Seems that all the inputs are pulsing except 9 and 10 which are at  
>> 0V. All the outputs seem to be at 0V.
>> I downloaded the 2316 datasheet and looking that the truth table:
>>
>> if CE = Low, WE = Hi and OE = Low, then the mode is READ, Output is  
>> ACTIVE, and power is ACTIVE.
>>
>> Unfortunately I don't actually know what all that means :-(
>
> It means the 2316 is being read.  Since it is being used as a  
> character ROM, that is normal.  Pins 9 and 10 being low would mean  
> you are not changing the 2 low bits of the character.  That would  
> mean that if you typed d, e, f, and g, the output would all be the  
> same.  Alternatively, the signal could be changing so fast your  
> probe cannot see it.
>
>
> wlevak@sdf.lonestar.org
> SDF Public Access UNIX System - http://sdf.lonestar.org
>
>      Message was sent through the cbm-hackers mailing list


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Received on 2009-11-22 02:00:04

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