ADVRAM, for what?

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By mars2000you

Enlighted (6259)

mars2000you's picture

03-12-2005, 12:39

See this page :

http://www.msxpro.com/aplicativos.html

From the Fudebrowser manual :

"FudeBrowser can also detect an ADVRAM and optimize itself for it.
Computers with ADVRAM can scroll the screen more or less 80% faster than
a computer without it.'

By Manuel

Ascended (18855)

Manuel's picture

03-12-2005, 15:33

Thanks for the hint, mars2000you Smile

By arnold_m

Master (173)

arnold_m's picture

03-12-2005, 20:49

ADVRAM can now also be emulated with the development version of openMSX.
I haven't done any real measurements, but fudebrowser does seem to scroll more fluently with ADVRAM.

By ricbit

Champion (438)

ricbit's picture

04-12-2005, 01:18

You can also try Video Test, the program I did to measure how fast ADVRAM was, when compared to other methods of copying data to VRAM. Download Video Test here:

http://www.700km.com.br/mundobizarro/advram/

By Yukio

Paragon (1540)

Yukio's picture

04-12-2005, 11:29

I could be wrong, but I think that some (maybe a long) time ago I heard something about the possibility of this type of implementation in a real MSX.

By Manuel

Ascended (18855)

Manuel's picture

04-12-2005, 16:34

Note that there are more MSXes with RAM in slot 0, page 2 and 3. An example is the Sony HB-F500P.

By PingPong

Prophet (3898)

PingPong's picture

13-11-2007, 23:06

It's a very interesing project. the most interesting part is the ability to achieve this on all msx'es and to overpower the gfx performances.
Cool the ability to execute z80 code from vram!
Cool the retained 100% compatibility of old vdp/vram interface
Cool the possibility to achieve more speed with a more speedy cpu (increasing clock, etc)

However:

Note also that the test program is created clearly to flavor z80:
- always byte aligned operations in modes different of screen 8
- screen 6 test are forbidden (has the more work to do to mask/unmask bytes)
- most test use screen 8 where 1byte = 1pixel and it's very easy to calculate vram address from x/y (simply store in HL)
- most test does not use trasparency to avoid in screen8 the reading and writing of vram (only a writing)
- Burst transfer operations, not rectangular based ones as more frequent in real world. (makes routines simpler)

doing exacly what the vdp does (including x,y in 16bit format, transparent format, logical operations, no byte aligned restrictions in logical operations, etc) will quickly degrade speed... WinkWinkWink

By mohai

Paladin (971)

mohai's picture

28-11-2007, 17:44

Could Ademir put the schematics on-line?

I wonder if he is not going to continue with the project, then someone else would like to do it...
Maybe implementation is not too complicated and a DIY article can be done ....

Is anybody in contact to Ademir?

By Manuel

Ascended (18855)

Manuel's picture

27-08-2015, 22:00

Does anyone know what happened to ADVRAM? Was it ever created on real hardware beyond a private prototype?

By tvalenca

Paladin (747)

tvalenca's picture

28-08-2015, 19:31

no, it never made beyond a private prototype. It's still possible, but I think Ademir had other priorities and stoped developing it.

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