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maprom 1.8 working on TT

Posted: 23 Feb 2021 16:43
by Steve
I just decided to try @agranlund 's maprom on my TT and it makes it marginally faster :) some slight decrease in vdi but overall faster. @tuxie

Gembench Vs itself before/after
PXL_20210223_162920020.jpg

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 16:54
by exxos
I think maprom really needs fast alt-ram to give speeds boosts.

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 17:36
by czietz
Is it any faster / different that what ROMSPEED would do on the TT?

https://seimet.de/atari/files/rmspd311.zip
https://github.com/uweseimet/atari_publ ... r/ROMSPEED

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 17:39
by Badwolf
That's a bit strange. 2x speed on ROM access, but display routines are only just break even, some getting worse?

Is there something clever going on under the hood of TOS3 normally?

BW

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 18:10
by exxos
Badwolf wrote: 23 Feb 2021 17:39 That's a bit strange. 2x speed on ROM access, but display routines are only just break even, some getting worse?
Never noticed that.. maybe @Steve can try without caches on to see if it drops ?

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 18:12
by Steve
Wow @czietz thanks for the tip, romspeed is amazing :)
PXL_20210223_181129272.jpg

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 18:19
by stephen_usher
Remember that the ROM access on the TT normally is 32 bits wide, which speeds it up somewhat. The TT-RAM interface is faster than the ROM but also 32 bit, so it doesn't make as much difference as it would on an ST+TF, which changes slow+16bit (two read cycles) to fast+32bit (one read cycle).

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 18:21
by czietz
EDIT: I see that I'm too late.

This is with ROMSPEED mentioned above - where the reference (=100%) is my TT running TOS from ROM:
IMG_4645.JPG
The absolute numbers are different from your TT because mine is accelerated to 48 MHz.

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 18:26
by Steve
@czietz guys you gotta sort me out with a speedy already! 8-)

Re: maprom 1.8 working on TT

Posted: 23 Feb 2021 19:27
by Badwolf
I had a go comparing the both on the Falcon @48MHz (speed relative to same configuration with hardware ROM).

As I expected, the results are pretty much the same.

MAPROM:
dfb1_maprom.jpeg

ROMSPEED:
dfb1_romspeed.jpeg

So does that imply MAPROM doesn't like the TT? (I have looked at the sources before, but it's all Greek to me :D )

BW