• Please review our updated Terms and Rules here

Just got a Mattel Aquarius, and it has issues...

D

DistantStar001

Experienced Member
Joined
May 8, 2019
Messages
178
As the title says, I just received a Mattel Aquarius but it isn't working. The power light comes on. It responds to the RESET button. But all I get is a garbage screen.
Screenshot 2023-04-13 at 2.19.32 PM.png
I tried reseating the only socketed IC (I think it's the ROM), and tried booting without it. The only difference was that instead of the characters shown, there were small rectangles on the screen. However, they were in the same locations on the screen.

Any ideas?
 
Welcome to the Aquarius club! I wish I could offer some help but I never had to repair mine. Ram isnt a bad idea however.
 
Hi, I saw your post on AA and replied there, but am sharing here as well for the sake of discovery.

When it's powered on (with volume on your TV up) press RETURN and check if you hear a BEEP and if anything visually changes on the screen. Then press CTRL + G to listen for another beep. If you at least hear the beeps, your system ROM and CPU are fine. At which point it could be bad RAM. There are two 2K RAM chips in there.

If you do get the beeps, you can try typing this in (blind) and press enter to see if the border changes to 'A' or any other change.

POKE 12288,65

There are two ULAs (plus a character ROM) that can go bad though I find that is rare, and unfortunately those are unobtainable beyond a donor Aquarius.
 
IS there an eprom ROm cart that can be made with Aquarius diagnostics? If so Id love to have a few printed but I havent come across gerbers yet.
 
MattPilz said:
Hi, I saw your post on AA and replied there, but am sharing here as well for the sake of discovery.

When it's powered on (with volume on your TV up) press RETURN and check if you hear a BEEP and if anything visually changes on the screen. Then press CTRL + G to listen for another beep. If you at least hear the beeps, your system ROM and CPU are fine. At which point it could be bad RAM. There are two 2K RAM chips in there.

If you do get the beeps, you can try typing this in (blind) and press enter to see if the border changes to 'A' or any other change.

POKE 12288,65

There are two ULAs (plus a character ROM) that can go bad though I find that is rare, and unfortunately those are unobtainable beyond a donor Aquarius.
Click to expand...
Replied on ATariAge, but no beeps. No response to the keyboard beyond the RESET button.
twolazy said:
Looks like bad ram...
Click to expand...
RAM, CPU, or reset signal! Here's hoping it's something like that. I've got a couple of spare Z80s, The RAM might be a bit more difficult. I needed to dig out my oscilloscope to check the reset. I was going to use a logic probe, but the battery on y multimeter just died, and I don't know where to find 5v.

If it is the RAM, and I can find some replacements, would piggybacking help diagnose them? I know that it won't work for the CPU, but sometimes it works for RAM.
 
Found my scope! Checked the reset pin (26) on the Z80 and it appears to go high on startup, but it doesn't come back down. Maybe I'm thinking 6502 here, but my understanding is that a reset line should either start high and go low, or start low and go high, after a second or two. Otherwise, the CPU will lock and not execute code.

Checking the rest of the pins, I get a good clock signal on pin 6, and all of the address lines show activity, but not the data lines. Refresh also has activity as well.
 
Stick your scope on pin 14 of the Z80 (D0) and then briefly short pin 26 (RST) to pin 29 (GND) and see if you really aren't getting any data bus activity
 
IT WAS THE PROCESSOR!!!!!



I would say it was a hunch. But the truth is that I have a couple of Z80s lying around, and a 40-pin socket or two, so I figured couldn't hurt. Also, I have no idea where to get a replacement ROM. And I have yet to get an E-Prom burner (really need to though). In any case, after I removed the old processor, it occurred to me that if that were the problem, then the fault screen would either resemble or be the same as what I was getting. so I tried it without the processor and got the same screen as before. Popped in a new Z80, and TA-DA!!! Working Aquarius!

Also, to answer my last question. No. The Aquarius's behavior does not change without its keyboard. In fact, it boots just fine.

Now that it's working, I've noticed some video quirks. For instance, the initial screen pic shown is monochrome. For some reason, my Samsung TV won't display any color with it. It has a similar issue with Atari 8-bits and Cocos. But usually changing the channel fixes that. The Aquarius, on the other hand, is strictly monochrome on this screen. I did get color on my little Sharp Aquos. But there was intermittent, but significant graphical glitching. Fortunately, it looks great on my old Sharp CRT TV from the '90s! Still, has anyone else noticed their Aquarius not playing well with LCDs?
 
The Aquarius has a slightly strange choice of video chip, the TEA1002, which is apparently only PAL? I'm not entirely sure how they manage to pull it off so that it makes a plausible output for NTSC TVs, it doesn't seem possible to just twist it with analogue wizardry in the RF modulator.

For what it's worth, the Aquarius works fine on my modern TCL LCD using a Master System RF switch box, although the signal is extremely noisy. I ordered some boards for the Aquarius AV mod, although the amplifier chip used is a little expensive.
 

Attachments

  • aquarius-basic-hello-world.jpg
    aquarius-basic-hello-world.jpg
    139.4 KB · Views: 4
DistantStar001 said:
IT WAS THE PROCESSOR!!!!!
Click to expand...

Excellent! I've found the Aquarius board to be really fragile when desoldering chips and it's easy to lift pads or traces.

I'd second the composite mod by Sean/1Stage. He offers a through-hole and surface mount version and it works well. There's one screw in particular that is very easy to strip when trying to disassemble and then can be a real pain to get out, so proceed carefully. He has a video on the Github or his website showing the full disassembly and install process.

And... Then if you get even more inspired you can look into building an Aquarius MX, which is the latest USB solution that also supports USB BASIC and a lot of new capabilities. There have been some nice homebrew creations for it this past year as well.
 
I had a similar issue where a blob of loose solder was bridging two data pins on my RAM, and it was driving me nuts trying to figure out.

Finally, when I re-seated the 2k RAM chip on the Aquarius motherboard, it caused the blob to pop off, and it was all fine.

- Sean
 
seat safety switch said:
The Aquarius has a slightly strange choice of video chip, the TEA1002, which is apparently only PAL? I'm not entirely sure how they manage to pull it off so that it makes a plausible output for NTSC TVs, it doesn't seem possible to just twist it with analogue wizardry in the RF modulator.

For what it's worth, the Aquarius works fine on my modern TCL LCD using a Master System RF switch box, although the signal is extremely noisy. I ordered some boards for the Aquarius AV mod, although the amplifier chip used is a little expensive.
Click to expand...
Yes, the NTSC version of the Aquarius fiddles with the TEA1002's outputs and frequency to make it work.

Apologies on the cost of the video amp chip. It was all I could find that could maintain a positive single-supply for the 75ohm video out. I'm sure someone far smarter than I could rework it with a more cost-effective chip. It's open source so, free to modify at will.

- Sean
 
MattPilz said:
And... Then if you get even more inspired you can look into building an Aquarius MX, which is the latest USB solution that also supports USB BASIC and a lot of new capabilities. There have been some nice homebrew creations for it this past year as well.
Click to expand...

The new MX BASIC 2.0 for the Aquarius MX is pretty stunning. We're finishing up unit testing, and the updated ROM file should be available in the Summer. It's also preview-able in AquaLite if you download the working ROM image from the GitHub at https://github.com/1stage/Aquarius-MX/tree/main/src/rom/v2-0 (aqbasic.rom file, 16k)
 
Gary C said:
Newer TV's often have real problems with old computers and their very lax interpretation of video standards so its not surprising.
Click to expand...

Depends on the noise and the built-in filtering of the input. Straight out of the RF modulator (stock Aquarius), with a good cable, it's pretty noise-free, albeit you have to do the CH3-4 thing and use the TV/CABLE BNC input on most sets. The Composite AV Adapter CAN be noisy, depending on the cable you use, the amount of ambient RF noise in the room, etc.

The REAL great output is the RGB-to-HDMI adapter that I've been working on for several years now. Since it's based on a RasPi Zero, and those are MUCH more expensive than the used to be, plus the CPLD that drives the logic is also pricey (for now), I had to back off on that development for a while.

The output is great, however. TJ Fereirra has a video showing off one of his Aquarius' that has the mod.
 
1stage said:
Apologies on the cost of the video amp chip. It was all I could find that could maintain a positive single-supply for the 75ohm video out. I'm sure someone far smarter than I could rework it with a more cost-effective chip. It's open source so, free to modify at will.
Click to expand...
No worries, thank you for making it. I am just opening up the RF shield on the machine right now!

I asked Analog for a free sample and they sent me one. :)
 
Very smart! Not a lot of people know that most chip/component manufacturers LOVE getting hobbyist requests for components. They WANT their technology to be accessible to people who are learning electronics. Most use either DigiKey or Mouser to fulfil those requests, so it's no skin off their nose, and they credit the warehouses on the shipping and inventory costs!
 
You must log in or register to reply here.
Back
Top