Installing alt-ram assembly problem

[terriblefire]

DMA does get screwed up.. but its odd.. Because there is only one Incorrect icon in a directory list on the floppy...

But video gets trashed totally, I just get a totally blank screen all the time, unless something crashes and I then can actually see bombs.. So it is like screen memory is getting allocated somewhere it should not be... I mean sysinfo would tell me that, but I cannot see the screen to check that :lol: :roll:

Dont know if this is anything to do with anything but the CDTV does something similar when you put fast ram in it (non-dma'able) fast ram. The buffer is allocated somewhere where DMA cant happen because the OS isnt smart enough to know about such things.

[exxos]

Dont know if this is anything to do with anything but the CDTV does something similar when you put fast ram in it (non-dma'able) fast ram. The buffer is allocated somewhere where DMA cant happen because the OS isnt smart enough to know about such things.

Could be... AFAIK TOS allocates screen memory towards the top end of RAM.. so if it then has 12MB of RAM, nothing will ever access video RAM and it will remain white.. Which it does.

[stephen_usher]

I take it that there's a gap in the memory map between the ST RAM and your alt-RAM? If not I wonder if that might be confusing the ROM code.

[terriblefire]

I take it that there's a gap in the memory map between the ST RAM and your alt-RAM? If not I wonder if that might be confusing the ROM code.

Thats a good shout. I've only ever tried adding alt-ram on a 1Mb STFM. There were no issues. Maybe this is why.

[mfro]

DMA does get screwed up.. but its odd..

If you add Altram that is not DMA accessible, you also need to allocate the FRB and set the _FRB cookie.
Are you doing that?

[exxos]

DMA does get screwed up.. but its odd..

If you add Altram that is not DMA accessible, you also need to allocate the FRB and set the _FRB cookie.
Are you doing that?

This all happens before it gets to desktop...