• Please review our updated Terms and Rules here

Desperation with Sharp MZ-80A ?

I thought you would like that! I had a hunch...

I suspect someone before you has been playing and adjusted L2002. The adjustment was causing the horizontal oscillator to run way too fast.

I suspect, if you monitor Q2003 collector (point 5) with your oscilloscope, we should observe the correct signal now.

I think what we were seeing before was feedback from the output of the horizontal oscillator.

This is why I don't like replacing components or twiddling anything unless I know what I am doing - and there is a good reason for doing what we are doing.

So, have you got the BASIC interpreter cassette to try?

Dave
 
daver2 said:
I thought you would like that! I had a hunch...

I suspect someone before you has been playing and adjusted L2002. The adjustment was causing the horizontal oscillator to run way too fast.

I suspect, if you monitor Q2003 collector (point 5) with your oscilloscope, we should observe the correct signal now.

I think what we were seeing before was feedback from the output of the horizontal oscillator.

This is why I don't like replacing components or twiddling anything unless I know what I am doing - and there is a good reason for doing what we are doing.

So, have you got the BASIC interpreter cassette to try?

Dave
Click to expand...
Thanks Dave! Tomorrow
I will try to test the q2003 collector with the oscilloscope! I also need to look for a non-original cassette that was sold to me with this computer and try it out! Do you think it is possible to move the centering of the screen slightly to the right?
Thank you so much for your help and patience!
Initially we had the fault that caused the resistor to burn out anyway, remember? Good night and see you tomorrow!
 
No problem. Have a good night.

There are no horizontal controls to twiddle on the PCB. Are there any centring magnets around the CRT tube neck or the CRT itself?


Dave
 
Sweet! Glad this is working now.

The manual h-hold on my JB-1260M(A) monitor got bonked in shipping and had to be re-adjusted for a couple sources. It was the last step of the project after fixing a broken sub-bright pot.

Good luck getting the software going! The MZ is a great series of computer.
 
seat safety switch said:
Sweet! Glad this is working now.

The manual h-hold on my JB-1260M(A) monitor got bonked in shipping and had to be re-adjusted for a couple sources. It was the last step of the project after fixing a broken sub-bright pot.

Good luck getting the software going! The MZ is a great series of computer.
Click to expand...
Thanks so much sir!
 
Q2003 collector
2V
20us
 

Attachments

  • 1701968042542..jpg
    1701968042542..jpg
    2.4 MB · Views: 2
That is spot on now...

So 14.53 kHz is what the horizontal frequency should have been.

So if we look back at the previous posts, I wonder what the horizontal oscillator itself was set to by L2002? I will have a search later.

Unlike the PET, these monitors have a horizontal oscillator that free-runs and is synchronised to the logic board by the synchronising signal. However, the oscillator will only synchronise if the frequency difference is within a tolerance.

In your case, the horizontal oscillator was outside of this tolerance, and therefore unable to synchronise to the logic board.

As a result, the logic board video signal becomes 'torn'. This Romulan text is what we saw on the original screen!

Dave
 
I tried this cassette but doesn t works! When i press load i have this message after some seconds
 

Attachments

  • 1701970427461..jpg
    1701970427461..jpg
    2.8 MB · Views: 7
Desperado said:
Maybe can i try to download one of this software....but how can copy in cassette?

MZ-80K Download - Operating Systems

MZ-80K Download - Operating Systems
original.sharpmz.org
Click to expand...
Okay, I actually did search this for you and could give accurate instructions, but as a thought experiment... on the cassette we have audio which corresponds to data. At that page we have data in a format known as MZF. If we wanted to record audio to a cassette using a PC and an ordinary cassette deck, something like WAV would be a good choice. Now, what kind of software should we be looking for?

Hint: It converts ____ format into ____ format.
 
onre said:
Okay, I actually did search this for you and could give accurate instructions, but as a thought experiment... on the cassette we have audio which corresponds to data. At that page we have data in a format known as MZF. If we wanted to record audio to a cassette using a PC and an ordinary cassette deck, something like WAV would be a good choice. Now, what kind of software should we be looking for?

Hint: It converts ____ format into ____ format.
Click to expand...
Hi Onre, thanks so much for your help!
Is this?

MZF2WAV

MZF2WAV
original.sharpmz.org
 
Desperado said:
Hi Onre, thanks so much for your help!
Is this?

MZF2WAV

MZF2WAV
original.sharpmz.org
Click to expand...
Yeah, I suppose if you ran this and recorded the resulting WAV onto a cassette, it should work. Just check that it goes to the tape at a hot enough level. Decks usually have some sort of level metering in them, you want it to be close to "red".
 
Desperado said:
But this computer doesn't have internal basic software?
Click to expand...
Correct, you have to load BASIC from the cassette.

I assume this model of computer has an inbuilt cassette drive?

So, if you have no idea what is on your black cassette tape cartridge, what are you loading (i.e. how do you know whether the hardware is working or not)?

You need to be loading an executable program (e.g. the BASIC interpreter or a game).

Dave
 
You must log in or register to reply here.
Back
Top