a1200 ham mode question

[KThunder]

hey all,
i just got an a1200 on ebay after not having a real amiga for a long time. everything seems to work perfectly except hame mode stuff- ham6 and 8 the mouse pointer gets weird. the pointer itseld is fine but below it are blocks of corrupted somthing or other.
everything tests fine and i have used numerous other screen modes and everthing works great. ive checked ham stuff with multiview with png support and cinima4d.
is this normal or what. i didnt do a real lot with ham mode satuff under fellow or uae, and it has been 5yrs i think since i had another amiga.

[Karlos]

By virtue of how HAM works, its possible too see some corruption to the right hand side of anything moving on the image (an effect called fringing). Good old DPaint in ham mode was a classic for this, especially the cross hairs and stuff.

However, this shouldn't affect your mouse pointer (AFAIK) since it is a hardware sprite and not rendered "into" the image, just drawn by the amiga's chipset "on the fly"...

[KThunder]

ive also played a bunch of games they all seem to be fine. except one that the pointer gets weird. just remembered that. thats a 32color screen mode. with that one the mouse actually changes and becomes a line partway across the screen

[KThunder]

if you have a ham mode screen up and you move the mouse around you dont see anything but the same pointer that is on workbench right?

[Karlos]

KThunder wrote:
if you have a ham mode screen up and you move the mouse around you dont see anything but the same pointer that is on workbench right?

Correct - as far as I recall (havent seen a genuine native screen in years :-( ). The pointer is a hardware sprite that is independent of the screen itself.

[KThunder]

hi
i did some more testing played more games changed screenmodes etc. it turnes out it is all interlaced modes that do it. all noninterlaced modes are pixel perfect. no problems. interlaced modes put garbage under the mouse pointer. i doubt ill be using interlaced modes for very much anyway im just hopind nothing else is wrong. this amiga had a rough trip from canada.

[Karlos]

It's a bit of a longshot, but maybe you should check your custom chips for hotspots.

A friend used to get a lot of corruption when using the dblpal modes and stuff, which was due to one of the chips getting a bit hot. We stuck a passive heatsink on it with some thermal paste and it was fine afterwards.