The Cambridge Dragon Meetup - June 3rd

A place to discuss everything Dragon related that doesn't fall into the other categories.
prime
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Joined: Fri Apr 10, 2009 1:40 am

Re: The Cambridge Dragon Meetup - June 3rd

Post by prime »

Hi all happy to bring my Alpha, she's still semi disassembled anyway from when I took the addon boards out to trace / reproduce.

Would be good also if I could get some measurements for the drive eject buttons as my machine doesn't have them.

Will bring soldering iron and tools too,and probably my two channel Rigol scope.
Will bring one of my 64s, and my expanded to 64K swichable coco/dragon plus the DragonMMC boards.

Anything else anyone wants me to bring? I remember somone wanting to borrow a multi-pak interface.

Cheers.

Phill.
admin
Site Admin
Posts: 409
Joined: Thu Jul 17, 2008 10:22 pm

Re: The Cambridge Dragon Meetup - June 3rd

Post by admin »

I *may* be able to help with the eject buttons - let me check my special box of bits as I also have 2 spare drives
Simon Hardy
tjewell
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Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: The Cambridge Dragon Meetup - June 3rd

Post by tjewell »

Well, I think the stage fright got the better of it, and my D64 just died. Video signal just went black when I was working on it. Here's what I've tried:

* MOTOR ON - It clicks. It even connects to drivewire and runs the AUTOLOAD when I turn it on.
* I've tried my D32 on the same monitor cable, and that works fine.
* I swapped the power daughter board from the D32 into the D64, and it still doesn't work (but does MOTOR ON). So I think this rules out a dodgy joint on the monitor socket and/or a power problem.

At this point I'm stuck! It's also my only D64, so unless I can repair it very quickly (with my extremely limited technical skills), some of my demos on Saturday are going to be improvised at best! :D

Any thoughts as to what it might be?

Also ... anyone coming on Saturday able to bring me a spare D64? Ideally with Tormod's extended basic, or doesn't mind me rummaging about inside their machine and swapping ROMs? I know, it's a big ask!

Roll on Saturday!
Cheers, Tony
sorchard
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Joined: Sat Jun 07, 2014 9:43 pm
Location: Norwich UK

Re: The Cambridge Dragon Meetup - June 3rd

Post by sorchard »

Hi Tony,

Sorry to hear your Dragon is playing up. It's worth checking the voltages the D64 power board is putting out anyway as the D32/D64 power boards are different. You should be able to find +5V, +12V & -12V.

Hard to imagine what would take out just the video like that and leave everything else working. There's a small -5V regulator on the main board: REG1/LM7905. Also video output transistor TR4. I had a failed SAM give blank video recently, though I didn't test if anything else was working.

If you have no luck then bring it along anyway, I'm sure one of us will be able to diagnose it.

Oh by the way: !!!DON'T EVER PUT A D64 POWER BOARD INTO A D32!!! Unless you want to supply -12V to all the places where -5V should go (e.g. the memory chips and video circuit)

I'm bringing a D64 with Tormod's DWLOAD ROM that you're welcome to use plus a D32 that's been upgraded to 64K. No monitors I'm afraid so I'm trusting to luck. (Well I've got a tiny PSOne LCD as emergency backup, but it's laughable really)
Stew
tjewell
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Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: The Cambridge Dragon Meetup - June 3rd

Post by tjewell »

Hi Stew,

Yes, I surprised how fast it happened - my first thought was that I'd accidentally changed input on the TV. Normally, things either fail slowly (flickering, being intermittent) or noisily (sometimes accompanied by a burning smell) and neither happened here! It stopped outputting video, just like that.

Still, if it was going to fail, it's picked a good time to do it - I think there'll be more Dragon experience in that one room than in any other time in the last 30 years! Together I'm sure we'll work it out.

Presuming my machine doesn't burst back into life, your machines could be asked to give some Fuzix and Orch-90 demos! I'm sure there will be monitors there, although I will bring a couple TVs just in case.

Oh, and good advice on the power boards - someone had mentioned that it wasn't a good idea to put a D64 board into a D32, but I didn't know why. Definitely won't be doing that then!

See you on Saturday, cheers, Tony
sixxie
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Re: The Cambridge Dragon Meetup - June 3rd

Post by sixxie »

"Amusingly", I've had a similar thing happen. I got a Dragon out of the loft and had it all set up and working. Next morning: no video.

It could be that a cat has been chewing on my lashed-up composite video lead though, as using the RF out worked fine.
sixxie
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Re: The Cambridge Dragon Meetup - June 3rd

Post by sixxie »

Well that was good fun! Lovely atmosphere & really good to put some faces to names.

Wish I could have chatted more - hopefully that went well enough there'll be a next time!
tjewell
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Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: The Cambridge Dragon Meetup - June 3rd

Post by tjewell »

Yes, definitely good fun! I too would have loved more time - there was a bunch of things I wanted to demo that I didn't get time for (and of course, a bunch of things that I tried to demo, and my computers didn't play ball!). I think it was great to see both history and future there - wonderful old prototypes and exciting new game developments. Getting to see behind the scenes at the museum was a lovely bonus too. What a collection they have ...

I'll collect together my photos and put them on Flickr or something, so those of you without Facebook can see them too. And I think that was enough of a success that we should consider doing it again next year - and it also gives us a deadline to get those demos done, hardware finished and game ports polished!

Thanks to everyone who came and made it such an enjoyable day,
Tony
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Bosco
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Location: Nottingham, UK

Re: The Cambridge Dragon Meetup - June 3rd

Post by Bosco »

It's nice to be involved with such a great retro community.

It was great having the opportunity to meet people in person, talk about projects or just say `thanks' to those whose help has been invaluable. :D
tjewell
Posts: 346
Joined: Mon Oct 19, 2009 4:58 pm
Location: Cambridge, England

Re: The Cambridge Dragon Meetup - June 3rd

Post by tjewell »

As promised, here's some photos! https://www.flickr.com/photos/mintyco/a ... 2658349510

Cheers, Tony
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