Re: FAT-40 PET board check pls?

Hi Mike,
thanks for hint! And yes, I know about the switch :)
8032987-06 might be why someone lifted pin 10 and 11 of UD2 on the
8032080 if they made the same mistake on the actual PCB.

On Fri, Jan 5, 2018 at 8:30 PM, Mike Stein <mhs.stein@gmail.com> wrote:
> 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
>>>
>>>
>>
>>       Message was sent through the cbm-hackers mailing list
>
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