How could someone use a interlaced screen free of flicker?

depends on who this someone is.

haha, no seriously:

Ive experimented a bit with interlacing, and the flickering will allways be visable,
Lets say page 0 displays all odd lines red, and the even ones are black
page 1 displayes all the even lines red, and the odd ones are black

If you would display page 0 the odd frames and page 1 the even frames you will allways see flickering.
Even in 60 Hrtz.

flickering looks less, if the black lines were orange.

What exectly would you like to use interlacing for?

You could use a LCD monitor Otherwise use small color differences between horizontal lines, so not one
black line followed by a white.

Quote:

What exectly would you like to use interlacing for?

To display CGI in BLS.

A LCD would work?

Do you know something about Scan-Doublers?
Is this a efficient method?

There is something about a a Dobrador SVGA for MSX.
http://www.carchano.com.br/portal/dobrador.asp?codigo_produto=67&pagina=dobrador.asp&nome=Dobrador%20SVGA&preco=R$%20360,00&texto=Sob%20Encomenda

Unfortunately my LCD screen and scan doubler are currently in use by some fellas who needed by computer & screens as rendering power for an upcoming LPG music video... as soon as I got 'em back, I'll test some interlaced things on them and will report about it...

I will be waiting ...

Well, if you are trying 524 lines interlaced, once i did a routine that worked pretty well. I remember there is a flag in one VDP register that says wich field is being displayed. All you have to do is:
- wait for VSYNC
- display one field (change page)
- wait for FIELD flag to change
- display other field
- return from INT

Only thing i do not remember is which field to show first. You will have to try-and-fail.

rgds,
IvI