Stefan Boer, 00-00-94
- THE VIDEOCHIP OF THE FUTURE -
V 9 9 9 0
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There have been no real new hardware developments for the MSX since the MSX
turbo R. But now the MSX-Hndlergemein- schaft from Switzerland are working on
the "Graphics 9000", a 16-bit videocard for the MSX turbo R with the new V9990
by Yamaha. The "Graphics 9000" will be available in October or November 1994
for approximately US$ 290.
EVALUATION BOARD
Since the International MSX Fair in Tilburg on March 26th 1994 I'm the proud
owner of one of the 10 V9990 evaluation boards which are in Europe at the
moment. The evaluation board is a print (appr. 6" x 6") with a lot of
electronic stuff I don't understand with in the middle the V9990 itself which
is square like the R800. The V9938 (MSX2 videochip) and V9958 (MSX2+) were
rectangular. The connections on the board include a connect for an interface
to the MSX turbo R and one for a scart lead.
You can connect the board to a monitor or TV directly with a scart lead, so
the image of the V9990 goes directly to the monitor. This is a small
disadvantage if you have only one monitor like me, because this means you have
to switch the leads when you want to work on the V9990 after working on the
V9958 or vice versa. This problem will probably be solved with the Graphics
9000.
You can connect a VGA monitor (640x400 or 640x480 in 16 colours) or even an
LCD to the V9990, but unfortunately I haven't been able to test this yet.
V9990 BASIC
If you connect the V9990 to your turbo R and monitor and you switch the
computer on, the screen will remain blank at first. This is because the
operating system of the turbo R still uses the V9958. You have to execute a
V9990 program before you can see anything.
Henrik Gilvad from Denmark modified the BASIC of the turbo R so it works with
the V9990. He also modified the KUN compiler (also known as XBASIC). The V9990
BASIC, BIOS and KUN are loaded into the DRAM (*) of the turbo R. The BASIC is
not completely compatible with the normal BASIC, it doesn't have to be and
it's not possible due to some hardware differences. But there aren't so many
differences so it's not hard at all to program something in the V9990
(KUN)BASIC.
(*) Note: Because ROM is significantly slower then RAM on the turbo R, it has
the possibility to copy the ROMs to the upper 64 kB of the main RAM which is
called DRAM. The engine of the turbo R (S1990) makes it possible to use this
DRAM as "ROM".
An important difference between the V9938 and the V9990 is that the V9990
hasn't got a textmode. Henrik solved this problem by programming his own
textmode in the P2-mode of the V9990. It's a very fast 64-column textmode with
International character set, so the Japanese characters of the turbo R can't
bother you anymore.
The V9990 BASIC supports the following screen modes:
screen remark
0 64 column textmode
1 will be 32 column textmode
2 P1 mode (256 x 212 dualplane patternmode)
3 P2 mode (512 x 212 patternmode)
4 identical to SCREEN 2
5..12 identical to MSX2/2+ except the sprites, only 2 sprites in
one colour are possible
The V9990 supports a lot more screen modes, which can easily be selected by a
few VDP commands. For example, you can select the overscan mode by OUT &H67,1.
In the overscan mode you can use the entire screen, including the borders! The
resolution is 384x240 in stead of 256x212 or 768x240 in stead of 512x212.
The following graphical instructions are supported by the V9990 BASIC:
BLOAD,S, BSAVE,S, CIRCLE, COLOR, COPY, DRAW, KEY ON/OFF, LINE, LOCATE, PAINT,
POINT, PRESET, PSET, PRINT, PRINT USING, PRINT#, PUT SPRITE, SCREEN, SET
ADJUST, SET PAGE, SET SCROLL, VDP, VPEEK, VPOKE and WIDTH. Of course the
non-graphical instructions are not modified.
512 kB VRAM
The V9990 has a lot of VRAM: 512 kB!!! This means that you have 16 pages in
SCREEN 5 and 6 and 8 pages in SCREEN 7..12. Doesn't something like SET PAGE
13,15 look great?!
SPEEDY GONZALES
The V9990 is extremely fast!!! For example, you can make a full screen smooth
scroll in SCREEN 5 with a BASIC program using COPY! The copy command of the
V9990 is 9 times faster than the "high-speed" copy command of the V9938! On
the V9938 you have to use a "logical" copy if you want to copy pixels in stead
of bytes or if you want to use logical operations. On the V9990 this isn't
necessary so those copies are 23 times faster!!! Note: In MSX-BASIC all copies
are treated as logical copies on the MSX2/2+/turbo R, so the COPY command in
BASIC is 23 times faster with the V9990 BASIC!
I/O SPEED
The V9990 has faster commands but it also allows faster I/O! The V9938 can
hardly keep up with the Z80, so the R800 of the turbo R is slowed down when it
communicates with the V9958. This isn't necessary with the V9990, so you can
really use the speed of the R800.
The evaluation board and Graphics 9000 use I/O addresses &H60..&H6F. These
ports are called P#0..P#F. P#0..P#7 are used for normal VDP operations,
P#8..P#B are for the kanji ROMs (not supported on Graphics 9000, but the turbo
R has its own kanji ROMs) and P#C..P#F are reserved for future use.
FLI-PLAYER
On the International MSX Fair in Tilburg on April 3rd 1993 Anarchy from
Germany/Switzerland released their Ray Tracing demo. This demo has a lot of
beautiful ray-traced animations in SCREEN 8, which are real-time decrunched.
It looks nice but it's not smooth because the V9938 is too slow.
Mi-Chi (a member of Anarchy) made a FLI-Player for the V9990. It works the
same, some of the animations were used in the Ray Tracing demo too. But on the
V9990 the animations are really SMOOTH!!! A fast harddisk (with SCSI interface
from Henrik Gilvad) is recommended because some of the .FLI files are 400 kB
and there is even a new .FLI player with files upto 2 MB. Unfortunately I
can't watch these large files because I haven't got enough RAM.
DRAWING PROGRAMS
The Graphics 9000 will be sold with two drawing programs. One for B1-mode,
256x212 with 64 colours out of a palette of 32768, and one for P2-mode,
512x212 with 16 colours out of a palette of 32768 colours. The B1-program
looks like DD-Graph and the P2-program will have a lot of options and used
pull down menus.
VIDEO
The Graphics 9000 will be capable of super imposing, which makes it ideal for
videofreaks. Mi-Chi is working on a program for animations, wipes, etc. The
advantages of the Graphics 9000 compared to the Philips 8280 are:
- the V9990 is much faster
- on the 8280 you can't use the border, the V9990 has the overscan mode
- the V9990 has better graphics (upto 512x424 with 32768 colours) for digis
Digitizing is not possible yet with the V9990, but it will be possible and
that will be amazing because you can digitize in the 512x424 mode with 32768
colours!!! This means that you can't see the difference between the digi and
the original!
One of the demodisk are two 512x424 YUV digis. These digis are really
brilliant, you can't see the difference with normal TV quality! YUV is a
system for encoding 19268 colours using only 8 bits per pixel similar to the
YJK system used in SCREEN 12 on the MSX2. It has the same disadvantage as YJK
(colour spill because 4 adjacent pixels have the same U and V values, only the
brightness (Y) can be different for each pixel), but you can hardly see it in
such a high resolution. You can imagine the quality of pictures with 32768
colours without colourspill!!!
GAMES
I'm the programmer of UMAX, famous from our games Pumpkin Adventure and The
Witch's Revenge. It's very frustrating if you can't program what you want
because the possibilities and/or speed of the videochip. This happens a lot if
you program something for the MSX2! The number of characters moving on the
screen and the size of them is a problem, and a nice scrolling routine is even
worse.
The V9990 has two modes ideal for games: P1 and P2. These are patternmodes,
the screen consists of patterns of 8x8 pixels each. The resolutions are
256x212 and 512x212. With these pattern modes it is much more easy to make
much nicer games for the V9990 than for the MSX2!
DUALPLANE
The P1-mode is better known as the dualplane mode, because it has two screens
which can scroll independently! You see the back screen where the front screen
is transparent. It's very easy to make fantastic multi layer scrolls using
this dualplane mode! Each plane can have one of the 4 palettes of 16 colours
out of 32768.
A very special feature of the P1-mode is a kind of hardware screensplit. You
can select a kind "border" in 64-pixel units. Above and on the left-hand side
of this border plane A is the front plane, and below and on the right-hand
side of this border plane B is the front plane.
PATTERNS
Because the V9990 has so much VRAM it can store over 15000 patterns. The
format of the patterns is very nice, it's equal to a SCREEN 5 picture with 8x8
blocks. So it's very easy to use the patterns!
Games for the MSX2 are often in SCREEN 5 and use 8x8 blocks. The screen
construction routine for such games is rather complicated, because for each
pattern you have to calculate at which coordinates it is in the VRAM, and it
has to be copied to the right position on the visible screen. This is slow and
difficult.
On the V9990 it's both very simple and fast: just VPOKE the pattern number (16
bits) in the pattern nametable. Are you now beginning to understand what I
mean with "it is much more easy to make much nicer games for the V9990 than
for the MSX2"? But this is not all!
SPRITES
In P1 and P2 modes you can use upto 125 (one hundred and twenty five!)
sprites, which is almost 4 times as much as the 32 sprites of the V9938. Upto
16 sprites can be displayed on a single horizontal line, so the times of
blinking sprites are over!
But the main advantage of the sprites is that, just like the patterns, they
are SCREEN 5 graphics! So you can draw 16x16 sprites in DD-Graph and just load
that into the VRAM. Without any conversion you can use those 16x16 blocks as
sprites.
On the MSX2 each horizontal line of a sprite can have only 1 colour, on the
V9990 all colours out of one of the four palettes of 16 colours out of 32768
can be used. It is possible to get multi-coloured sprites on the MSX2, but you
have to use 2 sprites for one "object" to get 3 colours on a horizontal line
so you can only have 16 of those 3-colour sprites!
If you want the sprite to move behind a fence and still see the part of the
sprite not covered by the fence, that's very hard to do on the MSX2. But all
you need to do on the V9990 is putting the fence at the front plane and
setting one bit of the sprite attributes!
Another advantage of the V9990 is that in the 512x212 P2-mode the spritepixels
have the same size as screenpixels. On the MSX2 one sprite pixel is two screen
pixels wide, and the x-coordinate can only be 0..255, on the V9990 the x-
coordinate can be 0..511.
The B-modes haven't got sprites because they were not designed to use for
games. They do have two special 32x32 cursor sprites.
SOFTWARE
The V9990 is ideal for games, business applications and video applications.
Mountainsoft from Switzerland are working on a game, there will be a V9990
version of the DTP program Aladin and a lot more software (including the
drawing and video programs I already mentioned) are being developed.
Henrik made a program to watch pictures from a Photo CD using a CD-ROM drive
and V9990 and Mi-Chi made a very professional viewer for a lot of formats
including.gif, BMP and PCX. The.gif, BMP and PCX pictures look a lot better on
the V9990 than on the MSX2 because the V9990 can display more colours (32768)
at a high resolution (512x424).
A lot of groups, including UMAX, have plans to make a game for the V9990.
INTERRUPTS
These paragraph is interesting for programmers, if you don't know anything
about interrupts you'd better skip it.
The V9990 can generate interrupts caused by the following events:
1) Vertical blank (50/60 Hz)
2) When displaying a certain line (line interrupt)
3) When a command is finished
4) When displaying at a certain HORIZONTAL position
5) At the start of displaying EACH line
The V9938 only supports 1 and 2. The advantage of 3 is clear. With 4 you can
make a "vertical screensplit", which is not possible on the V9938 (not a
stable one) and 5 is very nice for "waves".
To see what caused the interrupt you have to read a status register on the
MSX2, on the V9990 you only have to read the interrupt flag port (P#6) which
is much faster.
PROGRAMMING
Programming for the V9990 is more simple or at least as simple as programming
for the V9958. A lot of things take less IN/OUT instructions and so they take
less time and less bytes.
I already mentioned the interrupt flag port, the V9990 also has a status port
with a lot of nice things like "vertical non-display period", "horizontal
non-display period", "command being executed", etc. Reading from/writing to
the VRAM is more simple too, just compare the following routines to see what I
mean!
; SetWriteV9938
; In: CHL = VRAM address (17 bits)
LD A,H
AND #3F
OR #40
EX AF,AF'
LD A,H
OR C
RLCA
RLCA
OUT (#99),A
LD A,128+14
OUT (#99),A
LD A,L
OUT (#99),A
EX AF,AF'
OUT (#99),A
RET
; SetWriteV9990
; In: EHL = VRAM address (19 bits)
LD C,#64
XOR A
OUT (C),A
DEC C
OUT (C),L
OUT (C),H
OUT (C),E
RET
RESOLUTIONS AND COLOURS
The V9990 supports the following resolutions:
mode resolution remark
P1 256x212(424) dualplane patternmode
P2 512x212(424) patternmode
B1 256x212(424)
B2 384x240(480) overscan
B3 512x212(424)
B4 768x240(480) overscan
B5 640x400
B6 640x480
Interlaced vertical resolutions are shown in parentheses "()". These
resolutions can be combined with the palette systems below, so a lot of
different types of screen modes are possible. Systems using 8 or 16 bits per
pixel are not possible for B4..B6, P1 and P2 only work with 4 bits per pixel.
bits/
pixel colours system
16 32768 simultaneously (TrueColour)
8 64 out of a palette of 32768
256 like SCREEN 8
19268 like SCREEN 12 (YJK)
19268 YUV
4 16 out of a palette of 32768
2 4 out of a palette of 32768
DISPLAY SIZE VS IMAGE SIZE
A very nice feature of the V9990 is the image size, which is much larger than
the actual display size most of the time, so you can only see a part of the
total "image" on your screen. Which part is determined by the scroll
registers, so you can scroll smoothly in all directions in all screen modes.
The image size depends of the number of bits used per pixel. The following
table is valid for the bitmap modes (B1..B6).
bits/pixel resolutions
2 256x8192, 512x4096, 1024x2048, 2048x1024
4 256x4096, 512x2048, 1024x1024, 2048x 512
8 256x2048, 512x1024, 1024x 512, 2048x 256
16 256x1024, 512x 512, 1024x 256
In the P1 mode there are two images of 64x64 patterns each (512x512 pixels),
the P2 mode has one image of 128x64 patterns (1024x512).
If you use the B1 mode for a game you can put an entire level of the game into
the VRAM, because there is space for 16 screens if you use 16 colours. You
don't have to use blocks but you can just draw the entire level. Of course the
P1 and P2 modes are better for games because they have sprites.
INTERLACED
The V9938 also had an interlaced possibility, but it wasn't used very often
because the odd lines of the picture have to be in one page and the even lines
in another. Because of this a picture has to be converted before it can be
shown in interlaced mode. Because of this animations are almost impossible.
The interlaced mode of the V9990 is much nicer, because it just doubles the
display size of the picture. No conversions are necessary and animations are
just as easy as in a non interlaced mode.
By the way, the V9990 has a undocumented mode with 16 colours and a horizontal
resolution of 1024. Together with the interlaced possibility the maximum
resolution a V9990 can show on a normal TV is 1024x424! I must admit the
quality isn't very high on my TV, but this should improve if you use a better
monitor.
FINALLY
I didn't cover all the possibilities of the V9990, but I think it is more than
clear that this videochip offers revolutionary possibilities on an MSX.
A lot of things that are not possible at all on a V9958 or only with a lot of
trouble, can be programmed for the V9990 in just a few lines of BASIC! You can
imagine what the possibilities are if you use machine code!
I'm going to start with a V9990 programming course in both BASIC and ML as
soon as the Graphics 9000 is available.
It's a pity the V9990 wasn't finished soon enough (autumn of 1991) to be used
in the MSX turbo R, which was released in the autumn of 1990. Most MSX users
have ancient hardware nowadays. The V9938 was developed in 1985, so it's
almost ten years old. On other systems it's very normal to upgrade your system
every few years.
This has been possible on the MSX (MSX1 1983, MSX2 1985, MSX2+ 1988, MSX turbo
R 1990), and now it will be possible again to upgrade your system with a
Graphics 9000 and a Moonsound (16-bit soundcard with OPL4). I hope that a lot
of MSX users around the world will buy a Graphics 9000 and a Moonsound.
Of course there isn't so much software at first, and because of this people
don't buy the Graphics 9000, there will be no more software for it, etc. We
have to break this vicious circle! Just buy a Graphics 9000 (and a turbo R if
you haven't got one yet), then the software will follow soon. I can assure you
a lot of groups who develop software can't wait to start programming for the
V9990!
A lot of groups who are developing software for the MSX2 at the moment are not
challenged anymore, they made a few games and they want to move on. This is
not possible with the MSX2. If we don't upgrade our hardware they will start
developing software for other systems like the PC. Unfortunately a lot of
groups already made that decision. The only way to stop more groups to take
this bad step is to support the new Graphics 9000 and Moonsound.
Stefan Boer
smboer@cs.vu.nl
(c) Sunrise Foundation 1994
Sunrise Foundation
P.O. Box 178
1530 AD Wormer
The Netherlands
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