cbm8032 crashing at end of tape load...

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cbm8032 crashing at end of tape load...

Didier Derny
now the cbm8032 is powered with 12v DC with 2 diodes added on the
circuit to drop the 12v to about 10.8v  (9.3v on unregulated connector)
when I check the 6v  on the tape connector it is at about 6.05v seems
correct

when I try to save a program everything looks ok
when I try to load a program seems ok to the ready but no cursor ?
any idea ?

I may have a clue... the cursor blinking seems irregular  I guess a
problem with the irq ?
any idea how the irq is generated on the 8032 ?  6522 ?

thanks

--
didier




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Re: cbm8032 crashing at end of tape load...

Christian Dirks
I think /IRQ is generated by the 6520 on UB12 by VERT DRIVE on CB1,
coming from the CRTC through the 7486 on UC2.

Am 04.11.2016 um 21:46 schrieb didier derny:

> now the cbm8032 is powered with 12v DC with 2 diodes added on the
> circuit to drop the 12v to about 10.8v  (9.3v on unregulated connector)
> when I check the 6v  on the tape connector it is at about 6.05v seems
> correct
>
> when I try to save a program everything looks ok
> when I try to load a program seems ok to the ready but no cursor ?
> any idea ?
>
> I may have a clue... the cursor blinking seems irregular  I guess a
> problem with the irq ?
> any idea how the irq is generated on the 8032 ?  6522 ?
>
> thanks
>
> --
> didier
>
>
>
>
>       Message was sent through the cbm-hackers mailing list

--
Christian Dirks
[hidden email]




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Re: cbm8032 crashing at end of tape load...

Didier Derny
Hi,

thanks for the information, I'll have to check these signal

I guess the signal leaving the 6545 is or I would have a bad display...

everything looks like if there was another source of irq above the one
from the crtc...

the cursor looks mostly good but some time kind of high speed blinking


btw I discovered that on the address lines he the level 'high' was
around 2.5v (with a 5.05v on vcc of the 6502)

it looks a bit low I'll have to check another machine..


thanks



On 05/11/2016 12:50, Christian Dirks wrote:

> I think /IRQ is generated by the 6520 on UB12 by VERT DRIVE on CB1,
> coming from the CRTC through the 7486 on UC2.
>
> Am 04.11.2016 um 21:46 schrieb didier derny:
>> now the cbm8032 is powered with 12v DC with 2 diodes added on the
>> circuit to drop the 12v to about 10.8v  (9.3v on unregulated connector)
>> when I check the 6v  on the tape connector it is at about 6.05v seems
>> correct
>>
>> when I try to save a program everything looks ok
>> when I try to load a program seems ok to the ready but no cursor ?
>> any idea ?
>>
>> I may have a clue... the cursor blinking seems irregular  I guess a
>> problem with the irq ?
>> any idea how the irq is generated on the 8032 ?  6522 ?
>>
>> thanks
>>
>> --
>> didier
>>
>>
>>
>>
>>        Message was sent through the cbm-hackers mailing list
>


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Re: cbm8032 crashing at end of tape load...

Greg King-3
On 2016-11-05 10:51 AM, didier derny wrote:

>
> Thanks for the information; I'll have to check those signals.
>
> I guess the signal leaving the 6545 is OK; or, I would have a bad display.
>
> Everything looks like if there was another source of irq above the one
> from the crtc.
>
> The cursor looks mostly good; but some times, a kind of high-speed blinking.
>
> On 05/11/2016 12:50, Christian Dirks wrote:
>> I think /IRQ is generated by the 6520 on UB12 by VERT DRIVE on CB1,
>> coming from the CRTC through the 7486 on UC2.
>>
>> Am 04.11.2016 um 21:46 schrieb didier derny:
>>> Now, the cbm8032 is powered with 12v DC, with 2 diodes added on the
>>> circuit to drop the 12v to about 10.8v (9.3v on unregulated connector).
>>> When I check the 6v on the tape connector, it is at about 6.05v, seems
>>> correct.
>>>
>>> When I try to save a program, everything looks OK.
>>> When I try to load a program, seems OK to the "Ready."; but, no cursor --
>>> any idea?
>>>
>>> I may have a clue: the cursor blinking seems irregular.  I guess a
>>> problem with the irq.
>>> Any idea how the irq is generated on the 8032?  6522?

The CRTC makes the "Jiffy" interrupt.  The datasette driver disables
that one, and uses its own higher-rate timer interrupt.  When it
finishes, it disables its interrupt, and re-enables the Jiffy one.

But, it looks as though the datasette IRQ isn't being disabled on your
machine, after a LOAD.

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