[atari7800] Some questions..

Newbie hat firmly in place, so bare with me :)

I've started tinkering with the 7800 now I've got some time on my hands, and
it's a lovely machine, but I've got a few questions, that I could probably
answer myself if I could run on a real 7800, but I can't ;) I've just bought
a PAL 7800, but now need to obtain something to program the bugger with and
missed out on the CC2 by a mile, but that and my path to making a dev kit
are another story..

Firstly..
Is there anyway at all I can force a DLL to restart from a new address, even
through using DLIs ? For some little tests I've reached the point where I've
got DLs for every scanline, and I've reached the limit of the DLL not being
able to be longer than 512 bytes.. Is there anyway I can force the DLL to
restart ? Switching the DMA off, point it to new one, then back on, or
something ? Ideally being able to have 2 DLLs, one for the top half of the
screen, one for the bottom ?

Also, CharMap access.. I'm confused with the timings ?
Am I correct in understanding that for example:

        2 byte wide chars of 20 characters:
                12 Cycles - 5 byte header
                20 * 3 Cycles - Character Map Access
                9 * 20 Cycles - Character Data fetch
                ---
                252 Cycles

        1 byte wide chars of 40 characters:
                12 Cycles - 5 byte Header
                40 * 3 Cycles - Character Map Access
                6 * 40 Cycles - Character Data fetch
                ---
                372 Cycles

These figure just don't seem right to me ? Though I guess they are, but I'm
just looking for clarification..
                
I've been looking through emulator sources but even then the timings seem to
be inconsistent ?

In general sprite usage I'm in love with this machine and the way it renders
:)

One last thing.. I recall seeing somewhere on Erics page that he found the
timings for Direct Graphic read from RAM were 2 cycles instead of the
documented 3 cycles ? I can't find this now, but I'm wondering if this is
correct ?
Does this apply only to the internal RAM, or does it apply to cart RAM in
the case of a SuperCart with RAM ? Just curious..

Regards
AndyM00

PS: On freelists.org trying to find the address to send mail to the list,
when you've not received yet any is a bit tricky ;) Nowhere does it simply
say atari7800@xxxxxxxxxxxxx! I'm guessing this is the right address..

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