I think the Video systems of the MSX and CPC seem to be very different. Asking if the Amstrad has a fast videochip is not really a valid question as the Videochip just displays a 16k section of the primary 64k, meaning no specialist VRAM or sprites like the MSX. Consequently the Video Ram is accessed in the same way as the normal ram.

To copy bytes to the screen is as simple as doing an LDI, or LD (hl),a. Whether you consider that fast or slow is a matter of opinion, but I'd say slow. You tell me? I'd love to know. Admittedly only having 16k to shift would be less than 64k of mode 6.

Well, the bottleneck on the MSX system is really moving data from the Main RAM to the Video RAM. This has to be done by the CPU, which of course is very time consuming. Once data is actually in the Video RAM though, things aren't half that bad. The V9938 has a blitter, which can do a number of simple tasks, such as doing logical copies, highspeed moves, fills, lines and whatnot. Sure, we all wish the darn thing were faster, but considering the time and age these beasts are from...

Anyhow, mode 6 is indeed a little 'heavier' than mode 5 would be, but unlike wolf suggests, it's very possible to make a GUI in mode 6 as well. That, of course, doesn't change the fact that however fast you get your routines to work in mode 6, they'd still be twice as fast in mode 5. All in all though, the ability to draw filled rectangles, lines and copy text-data using VDP commands must make rendering the screen a bit easier than it is on the CPC. How fast it will turn out is just a matter of trying it, but the fact that other mode 5 GUIs were reasonably fast means it's certainly possible.

Wouldn't the GFX9K be a consideration worth as well?

nah, there's no challenge in that!

I think it would be nice that such an OS would work on a standard MSX2, but I also think it would be nice to take the benefits from additional hardware expansions, like in a bonus feature.

Just use drivers for your OS. A V9938 driver and a V9990 driver

Somehow I have a little deja-vu.... Anyone ever heard of Contiki?

idd, once a working V9938 version is made, it's peanuts to 'patch' it for V9990. Anyhow, I checked the SymbOS, and apart from the fact that it is very cool (try it ppl), I didn't see anything special. Everything currently done can be done on the MSX2 as well, probably at the same speed, perhaps a little heigher. Judging from the fact that SymbOS seems to effortly switch between screen modes, I guess the same could be done for a possible MSX2 version. Especially when using commands, you would have to change very little to have the routines work on both modes.

Anyhow, I'm eager to hear about this possible port, please let us know how things work out. If you guys do decide to port it to MSX, let me know if there's anything I can do to help. A lot of people on the forums here would probably also be more than happy to give a few pointers, if it helps.

Quote:

Somehow I have a little rendez-vous.... Anyone ever heard of Contiki?

I think you mean "deja-vu" And yes, I've seen Contiki about 10 years ago or so; had no idea it still exists

Quote:

Quote: Somehow I have a little rendez-vous.... Anyone ever heard of Contiki? I think you mean "deja-vu" And yes, I've seen Contiki about 10 years ago or so; had no idea it still exists

hehe yeah... deja-vu is what I meant

Hi,
now I also reached this forum and read this discussion with great interest! Seems that the MSX scene is still extremely active, what is very impressive!
As the author of SymbOS I am surprised, that I didn't explore the great possibilities of this machine before. Trebmint and Jarek Adamski kicked me to study them, and I am very impressed!
About the video mode:
Mode 5 seems to be perfect for porting SymbOS in it's current state. Also the VRAM is not larger than 32K, which means, that I have 32K vram, 16K screen driver (ok, it's shorter) and 16K application data within the 64K address space.
Mode 6 is very interesting because of the high amount of colours, but it will be a little bit harder to implement.
What is absolutely cool are the blitter features, as I could use them directly in the screen driver (it is already designed for supporting such features!).
In SymbOS the screen driver is separated completely from the so called desktop manager. The desktop manager itself doesn't know anything about the video hardware, so writing different drivers is very easy.

Now I need to know exactly about the banking possibilities in the MSX? How can I switch ram pages and from where to where can I switch them? Is it possible to replace any 16K page in the 64K address space with any 16K page of the whole memory or are there any restrictions?
Also what's about the interrupts? As far as I know MNBIOS is using a 50Hz interrupt, which is too slow in my opinion (current SymbOS on CPC does the task switching at 150Hz.

Does someone have a link to some technical information?

Best regards,
Prodatron / SymbiosiS

members.chello.nl/h.otten/fronthw.htm

Here are a lot of datasheets you can use for programming on the msx

Thank you very much, I already found some useful information.
BTW, what MSX2 machine is recommendable? In my 8bit collection I own an Phillips VG 8235, would this be a good choice or not?
Best regards,
Prodatron / SymbiosiS

MSX2 is a standard... so it shouldn't make a difference which brand you take. The amount of memory can differ though but the majority has 128KB ram and 128KB Vram. The Philips VG8235 is one of the few with a 360KB FDD.... the majority has luckily 720KB.

150hz.. that's even faster then Windows. A standard MSX has only one interrtupt source.. generated by the vdp.. and it's 50 or 60hz...