exxos's Atari, Amiga & retro forum

HigashiJun wrote: 07 Jan 2022 12:09

rubber_jonnie wrote: 07 Jan 2022 11:58

Interesting.

Yes, and if you go with the Dragon 32, just check the following Retrohax page:

https://retrohax.net/dragon-32-64k-ram- ... -and-mods/

I'll be sure to!

I always wanted a Dragon 64 back in the day (and a Jupiter Ace) but both are way too expensive for my retro funds.
Maybe a nice Mac if the price is right...

JezC wrote: 07 Jan 2022 14:17 I always wanted a Dragon 64 back in the day (and a Jupiter Ace) but both are way too expensive for my retro funds.
Maybe a nice Mac if the price is right...

Don't get a Mac Classic unless you're mad in the head!

rubber_jonnie wrote: 07 Jan 2022 14:33

JezC wrote: 07 Jan 2022 14:17 I always wanted a Dragon 64 back in the day (and a Jupiter Ace) but both are way too expensive for my retro funds.
Maybe a nice Mac if the price is right...

Don't get a Mac Classic unless you're mad in the head!

I did specify a 'nice' Mac...probably a Quadra or later (to work with some music software) ;)

JezC wrote: 07 Jan 2022 16:14

rubber_jonnie wrote: 07 Jan 2022 14:33

Don't get a Mac Classic unless you're mad in the head!

I did specify a 'nice' Mac...probably a Quadra or later (to work with some music software) ;)

Fair enough. The Classic really isn't a nice Mac!

Ok, so first look inside the Aquarius and it is quite grubby:


There is a lot of dust, though corrosion does seem to be limited.

It does power up, but the screen has garbled colour data:


So a dig around for Aquarius info seems to be on the cards for me tonight.

I'm hoping it won't be anything wrong with a PLA and just either be RAM, Character Gen or ROM, as the PLAs are like they are in the Electron and hard to get hold of, and in the case of the Aquarius, not yet remade. More Ferranti stuff, who seem to be the only people able to make PLA/ULA chips at the time.

The keyboard has a slightly different problem (It was shown on the listing) in that the Z key is missing it's top!


I'm thinking that if I can remove the key sheet and fence off the Z key, I can repair it with something like hot glue or silicone, and then paint a letter on the top after recolouring. I doubt the key sheet will be something I can easily replace, but something else I can look for tonight.

The keys do all at least work and the membrane looks to be in excellent condition overall.

Parts ordered for this too: http://www.bhabbott.net.nz/micro_expander.html which will expand it nicely.

Hmm, putting the pieces together after finding a nice schematic online, I am thinking that after a cleanup, I may try and check over the signals at the TEA1002, which is the PAL encoder chip too.

It takes RGB signals from PLA2, and CSYNC from PLA 1 and outputs in composite to the modulator. Given that the signal is actually good and just the colours on the characters are messed up, then it could be the TEA mangling things, or it could still be RAM/ROM/CHARGEN problems. I'm still thinking RAM, but I think I'll need to bust out the oscilloscope and have a good poke around the video generation signals.

It's annoying, as I've yet to find any sort of service manual or tech reference that explains how video generation fully happens.

Next I think a clean is in order though.

@rubber_jonnie could it just be that it doesn't like your monitor? Thinking similar to the Apple //e thing. All the colours and characters are in the right place just distorted.

PhilC wrote: 07 Jan 2022 22:46 @rubber_jonnie could it just be that it doesn't like your monitor? Thinking similar to the Apple //e thing. All the colours and characters are in the right place just distorted.

It has no monitor output, not even composite.

I'm running via RF to an LCD TV, so I don't think so. I will pull out my period TV and check, but there are distinct blocks of colour around the characters like the "paper" on a Spectrum character. My gut feeling is that it's electronic.

Kinda looks like ram refresh fail .