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Operation thunderbolt pcb

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webster007 View Drop Down
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    Posted: 25 Mar 2020 at 10:48pm
Hi

For the corona shut down I have dug out my operation thunderbolt pcb to repair. When i first got it there was no sound. So I left it for a month, plugged it in again and it had a graphics problem. So it ended on the 'when I get the time' jobs.

Mission 1 - Repair graphics problem and restore hope

1 year later here I am.
Setup as follows

Graphic problem

I did some googling and someone had a similar problem and it was a broken/corroded address line track.
So I checked mine with an oscilloscope from source to eeprom and all looked good.
The question is what to check next?
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webster007 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote webster007 Quote  Post ReplyReply Direct Link To This Post Posted: 19 Apr 2020 at 7:25pm
I check all the address and data lines then realised that i was in the sprite graphics area. Doh

I then check the background Mask rom area and still all seems to be fine.



I popped the Mask rom out and read the chip. It did not compare with the Mame rom.

I ordered a replacement 27C400. It came this weekend.

Programmed it up and success. Tongue





Mission 2 - Get the sound working.

I am going to read all the EPROM and Mask roms first.
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paulcan69 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote paulcan69 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 2020 at 5:55am
How did you read it
As what chip?
Need to look at my faulty spare pcb
Thanks
And well done!!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheDaddy Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 2020 at 9:19am
Originally posted by paulcan69 paulcan69 wrote:

How did you read it
As what chip?
Need to look at my faulty spare pcb
Thanks
And well done!!
 

You need an adapter and read the banks separately as 512 using 27C4096. Then merge them to read & verify. TL866 good for this.

Dave.


Edited by TheDaddy - 20 Apr 2020 at 9:20am
AKA Wonderboy. If there is such a thing as reincarnation , knowing my luck , I will come back as me !!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote webster007 Quote  Post ReplyReply Direct Link To This Post Posted: 20 Apr 2020 at 12:45pm
I used a galep 4.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote paulcan69 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Apr 2020 at 8:32pm
Yeah I’ve got a galep 4
How do you read em
Can you write em?
Let me know if you don’t mind
I have an op thunder to fix
And need to read and write a couple of them for sure
One has already died and someone has put a custom in there
Like an adapter and newer style repo of it
Thanks in advance
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Post Options Post Options   Thanks (1) Thanks(1)   Quote webster007 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr 2020 at 12:54pm
The sprite mask roms B67-01 to 05 are MN234000 (fujitsu I think) and can be read using a 27C400 device.
The background mask rom B67-06 is a MN234000 (fujitsu I think) and can be read using a 27C400 device.
The sound mask roms B67-07& 08 are MB834100 and can be read using 27C4096 device.
The sound EPROM B67-13 is a 27C512
The main programme EPROM B67-14,15,20 & 23 are 27C1001
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Post Options Post Options   Thanks (0) Thanks(0)   Quote paulcan69 Quote  Post ReplyReply Direct Link To This Post Posted: 22 Apr 2020 at 5:39pm
Your a legend thank you
Took a picture of that and I can spend some time soon looking at that
Thanks to your reply
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Post Options Post Options   Thanks (0) Thanks(0)   Quote webster007 Quote  Post ReplyReply Direct Link To This Post Posted: 24 Apr 2020 at 4:54pm
So I read all of the mask roms and eprom and compared them to the mame roms and all looks good.

Now I get some background hum through the speaker and when I turn the volume up, it gets louder. This suggest the analogue amp is working.

Next I checked the yamaham sound chip YM2610 for serial data output, which was only a steady pulse, not much going on there. Then checked the analog out and it was just a constant 1v. So the YM2610 is not ouputing any sound. Checked the IRQ, which was constantly high.

I then moved back to the Z80, clockpulse working, RD & WR had activity but the address and data line looked very samey ie data there but not changing.

So I think it is either the Z80 or the RAM.

I am going to change the z80 first easier to get hold of instead of the Sony CXK5864BSP-10L RAM.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mc-Q Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 2020 at 3:13pm
6264 ram (or 62256) should be easy to find

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