PDA

View Full Version : Screen dragging


MickJT
01 January 2008, 17:36
One of the defining things the Amiga could do was let you pull the screen down by the title bar to reveal the one behind it.

It was done by custom chips, but don't tell me it can't be done by emulation. At first, in a beta, it could be designed to only work if the screen behind it has the same screenmode. In later versions, the screenmode behind it could be modified to match the foreground screenmode.

This is basically what happened on the real Amiga. You would open up a PAL program, switch back to your Multisync WB screen, then drop that screen down to reveal the PAL program running in a Multisync screenmode.

Don't tell me it's not possible. I'm not that naive ;-)

Jope
01 January 2008, 17:59
So, are you on about P96 screen dragging, or custom screen dragging?

The latter works fine in WinUAE, just like on the real machine.

P96 screens can't be dragged, just like on the real machine.

CGX supports screen dragging on the real machine, but there is no CGX driver for WinUAE's builtin graphics.

There are caveats to dragging RTG screens, mainly the amount of memory it draws and the slowness when flipping screens with dragging enabled.

Of course neither of these is a problem in emu, but they are very real on the real machine with most RTG boards only having up to 4MB video ram.

MickJT
02 January 2008, 18:25
Ahh ok, I thought screen dragging wasn't possible at all in WinUAE.