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Cbm dual drive 3040 disk - two red lights

Dave the programmer himself tells me when there is a need for an adapter ... in these cases it says that it is not necessary :(((
 
It is almost as though your EPROM programmer tool is driving the signals as a 2732 when selected as a 2532.

That is all I can think of at this point in time.

EDIT: No, I am not convinced myself about this...

Dave
 
daver2 said:
It is almost as though your EPROM programmer tool is driving the signals as a 2732 when selected as a 2532.

That is all I can think of at this point in time.

EDIT: No, I am not convinced myself about this...

Dave
Click to expand...
Maybe can i try to burn an eprom with the firmware ?
 
It's almost as though the A11 address signal is being sent by the programmer to pin 21 (CS2) instead of pin 18 (A11) as that would cause the chip to be enabled only during the second half of the read run. If the programmer is also sending the hold-high signal to pin 18 (A11) instead of pin 21, that would be why we see the correct contents of the upper half of the PROM once it is actually enabled during the second half. As if, as Dave just said, the programmer is trying to drive a 2732 rather than a 2532.

There again, Desperado says that it does function correctly when reading a 6332, so, duh...
 
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If Desperado scopes pin 18 and 21 of the programmer's socket while performing a 'read' (without a device in the socket) we should see that one of those pins is held high throughout the read operation and one of them goes low followed by high during the read operation. The one which goes low followed by high will be the one which the programmer considers to be A11.

Unfortunately these events will be fast, one-shot events so they could be quite hard to observe on a normal scope.
 
Desperado said:
Maybe can i try to burn an eprom with the firmware ?
Click to expand...
To what end?

What are you going to do with the EPROM once you have burnt it - unless you already have some adapters - in which case that is a good idea.

Yes, you are correct - it is A11 on pin 21 that would be the issue - but that is the programmer defaulting to a 2732 and not a 2532.

Of course, the EPROM programmer is all driven by software - and there is nothing to say that they have got it 100% correct for all devices...

How up to date is your firmware?

I like the idea of checking the pins of the EPROM out to see what is going on. You can just use a blank EPROM for these tests.

Dave
 
From your screenshot of the firmware in #124 I see a '?' icon at the upper right which usually leads to a 'help' area where the firmware version may possibly be, or if you can find an 'About' icon or menu item the firmware version may be displayed there.

I think we need you to try scoping pins 18 and 21 of the programmer's socket during a 'read' operation so that we can see if the correct signals are being sent to the correct pins for a 2532. Alternatively, you can try it with the logic probe if you can find +5V power for it from the programmer. What we are interested to know is which pin, pin 18(?), or pin 21(?), flips from low to high half of the way through the read operation.

For the purposes of this test only, the chip in the programmer's socket can be a 2732 if you have one, but you must still read it as a 2532. You may not need a chip in the socket at all for this test but it will make it easier for your scope probe or logic probe to make contact with the socket contacts if you do have a chip in the socket.

You will have to watch carefully because the low to high voltage change on the A11 pin (whichever one the programmer thinks it is) will only happen once every time you try a 'read'.
 
Read post #148.

Why are you jumping to the RAM now?

We are first trying to ascertain whether the ROMs are correct before we get diverted onto something else...

Dave
 
we need you to try scoping pins 18 and 21 of the programmer's socket
Click to expand...

Potentially misleading. I mean the socket pins where pins 18 and 21 of the 24-pin PROM are when it is inserted into the correct position in the large socket of the programmer - not pins 18 and 21 of the big 40 or 48-way ZIF socket on the programmer.
 
SiriusHardware said:
Potentially misleading. I mean the socket pins where pins 18 and 21 of the 24-pin PROM are when it is inserted into the correct position in the large socket of the programmer - not pins 18 and 21 of the big 40 or 48-way ZIF socket on the programmer.
Click to expand...
in practice, I have to insert the prom in the programmer and while I try to read it, I have to use the oscilloscope probe on the pins?
 
Yes, but you can use ANY PROM. What we are trying to observe is how the EPROM programmer drives pins 18 and 21 of the EPROM when you are trying to READ it. The contents of the EPROM are actually irrelevant.

Dave
 
daver2 said:
Yes, but you can use ANY PROM. What we are trying to observe is how the EPROM programmer drives pins 18 and 21 of the EPROM when you are trying to READ it. The contents of the EPROM are actually irrelevant.

Dave
Click to expand...
Better scope or logic probe?
 
Yes, but you can use ANY PROM
Click to expand...

We should perhaps limit this to any 24 pin PROM, as of course putting a larger device in will cause power to be applied to the wrong pin of the device. A 2732 would be ideal, but remember to still read it as a 2532.

If you can find power from the programmer itself, try the logic probe first.

If you can't easily power the logic probe from the programmer try the scope, and remember that your scope GND will need to be connected to GND on the programmer. We don't know what your programmer looks like, is it in a case or is it just a PCB with components and a ZIF socket on it?
 
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How is it connected to the computer which is controlling it. Via USB? Is the computer a laptop or a desktop type?
 
Ok I found the gnd at the power socket of the programmer, with the oscilloscope probe on pin 18 I have a high signal and when I try to read the Prom, it goes low for a second and then goes back up .... On 21 nothing happens instead ... no signal.
 
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