Sinclair ZX80 / ZX81 / Z88 Forums

I have a box...

Is it the Lambda Colour Pack?

Good guess
]

Does this Lambda Colour Pack work as an attachment to the ZX81, or is it strictly designed to be used with the Lambda 8300?

It works fine with the ZX81, but the code is a little different.

This is because the D-file on the Lambda 8300 is always in the same location, however on the ZX81 it moves around.

Unfortunately I can't answer that question, because...
That's why the in the subject line!

When my screen acts like that, I change the power to the computer a bit. Sometimes it just has too much or too little power.

So I start with 9V, and try also 6V and 12V. Usually one of the settings works better. Sometime the voltage needs a change when the computer gets warmed up.

Really? Without the colour module, it does give a normal output, albeit a little fuzzy...

It's because the Colour Pack needs some power as well.

The 7805 should be able to handle 12V. It will just be hotter.

12v, 700W I should add that Lambda's (en Your Computers and others) are not really my speciality! I've never seen one back in the day, not even advertisements as they were not sold here in the Netherlands.