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C64 IN PET S' CASE

With CRT connected i have this on jp2 pin 1
 

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The signals are clearly not TTL levels are they?

So, if the signals are OK with the monitor disconnected, there is something wrong with your hookup of the board to the monitor.

The VIDEO and (I guess) VDRIVE look wrong, but HDRIVE looks OK.

So what have you done?

Dave
 
daver2 said:
The signals are clearly not TTL levels are they?

So, if the signals are OK with the monitor disconnected, there is something wrong with your hookup of the board to the monitor.

The VIDEO and (I guess) VDRIVE look wrong, but HDRIVE looks OK.

So what have you done?

Dave
Click to expand...
I should have everything hooked up correctly Dave :(
 
Ok, but what about the other end of the cable (at the PET monitor end)?

And can you remind me what PET monitor PCB it is again - so I can look up the pinout for it.

Dabe
 
daver2 said:
Ok, but what about the other end of the cable (at the PET monitor end)?

And can you remind me what PET monitor PCB it is again - so I can look up the pinout for it.

Dabe
Click to expand...
The problem is the C64 Vic!!!
On post #232 the video signal was correct!! :(
 
daver2 said:
Ok, but what about the other end of the cable (at the PET monitor end)?

And can you remind me what PET monitor PCB it is again - so I can look up the pinout for it.

Dabe
Click to expand...
This is the monitor pcb
 

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Desperado said:
The problem is the C64 Vic!!!
On post #232 the video signal was correct!! :(
Click to expand...
But that signal is only 0.4V pk-pk.

I agree it looks different, but isn't that a function of how you are now measuring it with your oscilloscope?

We currently have a video portion, and a horizontal and vertical synchronisation component, otherwise you wouldn't be getting an HDRIVE and VDRIVE from your PCB.

If you are getting correct TTL signals from your little board, how can attaching a PET monitor to the output of your little board affect the VIDEO and VDRIVE signals if they are not connected to the C64?

If you think it is the VIC chip, either replace it or get another C64... And then we can either move on or wave the white flag.

It may be the VIC chip. Who knows now...

Dave
 
daver2 said:
But that signal is only 0.4V pk-pk.

I agree it looks different, but isn't that a function of how you are now measuring it with your oscilloscope?

We currently have a video portion, and a horizontal and vertical synchronisation component, otherwise you wouldn't be getting an HDRIVE and VDRIVE from your PCB.

If you are getting correct TTL signals from your little board, how can attaching a PET monitor to the output of your little board affect the VIDEO and VDRIVE signals if they are not connected to the C64?

If you think it is the VIC chip, either replace it or get another C64... And then we can either move on or wave the white flag.

It may be the VIC chip. Who knows now...

Dave
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Please what can i do now to solve this bad beast??? :(
 
JP2 pin 4 is ground , regardless of which way the connector is numbered because it is the middle pin. And it should have no signal on it. But post #2662 shows signal. Something has gone wrong with the connector wiring to the VDU, though if the VDU had not had the about correct H drive signal, there screen would never have lit up.

It is a simple arrangement, there are three active signals and each has a ground connection.

The pin numbering is different at the VDU end, because the plug is longer as pin 1 & 2 there carry the power supply voltages , 8 +9 carry the video, but still on that connector pin 4 is GND too.


Desperado; you are dealing with six wires from the VDU. Three are earths and three are signals H drive , Vdrive and Video. Please connect these correctly to your pcb. Make a new male connector to fit the 7 pin VDU plug and simply wire it onto your pcb correctly.

The original VDU connector (that plugged onto the commodore computer pcb), was a 7 way connector,one pin not used and blocked off to prevent the connector being plugged on in reverse.
 
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Hugo Holden said:
JP2 pin 4 is ground , regardless of which way the connector is numbered because it is the middle pin. And it should have no signal on it. But post #2662 shows signal. Something has gone wrong with the connector wiring to the VDU, though if the VDU had not had the about correct H drive signal, there screen would never have lit up.

It is a simple arrangement, there are three active signals and each has a ground connection.

The pin numbering is different at the VDU end, because the plug is longer as pin 1 & 2 there carry the power supply voltages , 8 +9 carry the video, but still on that connector pin 4 is GND too.
Click to expand...
No Hugo on J2 pin 4 i have Vertical drive.
 
Must i buy a new VIC ic or another C64...i suspect that i have problem with C64 signal.....
 
Desperado said:
No Hugo on J2 pin 4 i have Vertical drive.
Click to expand...
On J2 your schematic diagram shows pin 4 is gnd, and would be that way regardless if the numbering had got reversed. So how did you end up with the vertical drive on pin 4 ??

I have attached a diagram of the connector on the VDU's flying wires, that plugs onto your J2

According to your schematic of your new board, ignoring any pin numbering the sequence of signals is correct and whatever way the pins got numbered, pin 4 is always gnd.

The sequence is gnd, missing pin, Hdrive, gnd, Vdrive, gnd,Video. Its pretty simple.

The unused pin in the VDU plug is blocked off, makes sure the connector cannot get plugged on in reverse, in the correct position the pin is missing from the male half of the connector.

Your diagram on post 2667, if the pin numbers are considered, shows the connections are messed up. It pays to pay attention to the signals and connections, the way the connector is numbered is less important.(for example the Vdrive signal could be said to be on pin 3 or pin 5 depending which side of the connector was labelled initially as pin 1).

On the Commodore motherboard, where the VDU normally plugs onto, they decided to label the connector pin 1 where the Video signal (yellow wire) connects, but your J2 that was labelled as pin 7. It doesn't matter provided the connector gets plugged on in the correct direction, because the sequence of signals match up.
 

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Hugo Holden said:
On J2 your schematic diagram shows pin 4 is gnd, and would be that way regardless if the numbering had got reversed. So how did you end up with the vertical drive on pin 4 ??

I have attached a diagram of the connector on the VDU's flying wires, that plugs onto your J2

According to your schematic of your new board, ignoring any pin numbering the sequence of signals is correct and whatever way the pins got numbered, pin 4 is always gnd.

The sequence is gnd, missing pin, Hdrive, gnd, Vdrive, gnd,Video. Its pretty simple.

The unused pin in the VDU plug is blocked off, makes sure the connector cannot get plugged on in reverse, in the correct position the pin is missing from the male half of the connector.

Your diagram on post 2667, if the pin numbers are considered, shows the connections are messed up. It pays to pay attention to the signals and connections, the way the connector is numbered is less important.(for example the Vdrive signal could be said to be on pin 3 or pin 5 depending which side of the connector was labelled initially as pin 1).

On the Commodore motherboard, where the VDU normally plugs onto, they decided to label the connector pin 1 where the Video signal (yellow wire) connects, but your J2 that was labelled as pin 7. It doesn't matter provided the connector gets plugged on in the correct direction, because the sequence of signals match up.
Click to expand...
Hi Hugo, on J2 pin 4 ( on the video pcb project ) i have Vertical signal....Horizontal is on pin 6.... I connected J2 pin 4 with vdu connector pin 3...it is correct, it isn't ?
 
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