How to set the msx1 VDP in order to have a scr2
with only one pattern table in all the 3 parts of the
screen?

I would like to have a single pattern table at 0000h,
common to all the 3 parts of the screen, and to move
the sprite pattern table at 0800h where usuallty there
is the second pattern table.

I remember that this is an undocumented feature of the
msx1 vdp, but how to set the registers?

SCREEN1
VDP(0)=2
VDP(3)=159
VDP(4)=0

character pattern table: 0000-07FF
name table: 1800-1AFF
sprite attribute table: 1B00-1B7F
color table: 2000-27FF
sprite pattern table: 3800-3FFF

I stongly recommand you test it on a real msx before moving on... sprites might start cloning themselves

there's no problem if you don't use sprites of course

and there might be differences between the TMS and the V versions of the MSX1 VDP...

Naturally I need the room of the spare character pattern tables
for storing extra sprite pattern tables so I need sprites!

Difference in vdp behaviour is not very good for compatability

Do you know if this feature is unsupported by some VDP's?

Does this feature gives problems on TMS9918 or on TMS9928 ?

Does this feature gives problems on other MSX1 vdp's ?
Does this feature gives problems on other MSX2/2+/Tr vdp's ?

I use this feature for Vscreen in screen 4 and it works on MSX2/2+ and TR so I'm guessing it's compatible with pretty much all VDPs.

On my Philips VG 8020 it does not work correctly.
You could run the asm listing I posted in this topic (Post at 20:26).
If you're vdp works 'correctly' it shows 32 smiley's, otherwise 96 smiley's.

the pattern table and color table mirror feature works in both MSX1 VDP types, but it might be possible the sprites get mirrored unwantedly like ghostwriterp already posted... on later VDP's (MSX2, 2+, turboR) it doesn't give any problems... hence, I used it in Palette Editor.