Re: FAT-40 PET board check pls?

You're right; almost looks like an error in the schematic. Compare to the 8032087-06.

BTW, your friend/customer contacted me and his switch is on the way.

m


----- Original Message ----- 
From: "Francesco Messineo" <francesco.messineo@gmail.com>
To: <cbm-hackers@musoftware.de>
Sent: Friday, January 05, 2018 1:49 PM
Subject: Re: FAT-40 PET board check pls?


> Maybe I don't understand well this schematic:
> 
> http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/univ/8032081-06.gif
> 
> Does it mean that on 40-c the inverter input remains floating (ok....
> TTL, can be) and the inverter output (UD2 pin 10) is connected to
> another output (UD3 pin 5) ?
> That doesn't sound healthy to me.
> 
> On Fri, Jan 5, 2018 at 7:41 PM, Steve Gray <sjgray@rogers.com> wrote:
>> Well, that inverter shouldn't be used in a 40-column configuration, so it
>> shouldn't really matter.
>> Maybe someone just wanted a free inverter for something? Check J1 and J2. J1
>> should be closed and J2 open for 40-column.
>>
>> Steve
>>
>>
>> ________________________________
>> From: Francesco Messineo <francesco.messineo@gmail.com>
>> To: cbm-hackers@musoftware.de
>> Sent: Friday, January 5, 2018 1:35 PM
>> Subject: Re: FAT-40 PET board check pls?
>>
>> On Fri, Jan 5, 2018 at 7:13 PM, Steve Gray <sjgray@rogers.com> wrote:
>>> No, they're not supposed to be lifted, instead the jumpers J1 and J2
>>> should
>>> be properly configured.These pins are part of an inverter in the clock
>>> section to change the master timing. Its possible that this was an
>>> 80-column
>>> machine converted to 40.
>>
>> it's missing the additional video RAM to be an 80 column, all the
>> jumpers he could check where for 40-c.
>> Why one would lift those pins if converting a board?
>>
>>
>> Thanks
>> Frank
>>
>>> ________________________________
>>> From: Francesco Messineo <francesco.messineo@gmail.com>
>>> To: cbm-hackers@musoftware.de
>>> Sent: Friday, January 5, 2018 11:48 AM
>>> Subject: FAT-40 PET board check pls?
>>>
>>> Hi all,
>>> can anyone with a 4032 (crtc 8032080 assy) please check if UD2 pin 10
>>> and 11 are supposed to be lifted from the board?
>>> A friend, not on this list, is repairing one and asked about this, he
>>> found these two pins lifted. According to the schematic, they should
>>> not be lifted, but I've never seen an 8032080 assy to be sure.
>>>
>>> Thanks a lot
>>> Frank
>>>
>>>      Message was sent through the cbm-hackers mailing list
>>>
>>>
>>
>>       Message was sent through the cbm-hackers mailing list
>>
>>
> 
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