[comp.sys.atari.st] GEM programming, STE memory

SOCS18@vaxb.york.ac.UK (Vision Newspapers) (03/06/90)

Re : Preventing "Data is damages in drive..." dialogue.

I believe that you have to nobble the critical error handler vector
(evt_critic, I think) which is in the $4xx region, and documented in the
Abacus book. I haven't tried this, but I think that if you make it point
to an RTS you won't get the dialogue. Sorry this is so vague, but I'm quoting
from memory here.


Re : Mixing 256 and 1M SIMMs in the STE

In the lastest edition of ST World (English version) there is an ad. from a
company offering cheap SIMM upgrades for STE owners. The mention that the
520 STE has two 256K SIMMs fitted, while the 1040 STE has one 1M SIMM, and
that you can't mix the two. They offer to "upgrade" your 520 STE to 1Mb by
selling you a 1Mb SIMM, and buying back your 256K SIMMs for (wait for it) 10
pounds each!

They also offer 520 STEs upgraded to 1Mb for less than the price of a 1040 STE!


Re : Bitblt failure with GDOS

What device handle are you using when you do your v_opnvwk call? You must use 
the one returned by graf_handle if you're opening a screen workstation, or
you'll get no end of GDOS problems.


Re : AC_CLOSE messages

GEM sends all accessories AC_CLOSE messages when an application ends. This means
you get one when a program is launched from the Desktop (because the Desktop
program has now finished), or when you quit any other program. By writing a
little program that popped up an alert when it received AC_CLOSE, I found
that the AC_CLOSE message usually gets sent well after the program has actually
finished. For example, after quitting any program and returning to the Desktop
the "AC_CLOSE received" alert didn't appear until just before the Desktop
opened its first window.

This effect could be due to the fact that GEM won't let the accessory display
its alert until the main application makes some GEM calls (this is cooperative
multitasking remember). Any comments?

Regards,

Mathew Lodge
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