WebMSX and SVI-738 X'press -- correct Machine setting?

WebMSX supports just handful of machines and those are generic MSX setups that don't always have any real life references. Usually this is not a problem, but SVI-738 is kind of a special machine as it has MSX1 ROMs, but MSX2 VDP and that is what goes wrong now.

Due to MSX1 ROMs SVI-738 does not have 80-column support out of the box, so it must use some external program to support that... Either done by you or someone else... MSX1 ROMs are not aware of MSX2 VDP features, so not all registers are initialized same way as on MSX2. This means that on MSX1 emulation your program can't work as the VDP is wrong and on MSX2 emulation your program may work wrong if there are differences on how the 80-column display is implemented or there are ie. some uninitialized registers...

In this case it sounds to me like the 80-column program you have used has just initialized the VRAM addresses differently than how MSX2 initializes them by default. If you want to dig deeper in to this subject, check out ie. BASIC-command called BASE... It might be that your 80-column extension program don't obey the BASE-command directives.

If you have a program that works on your real machine, but not now on this emulator and you don't care so much to fix it rather than just see it running again, then changing emulator is likely the most easy solution. OpenMSX is currently most accurate emulator out there and can emulate ie. SVI-738 exactly. It has loads of other features as well, but unfortunately I must say that user-friendliness is not among the best features although it comes with launcher called Catapult. You will need to get original SVI-738 ROMs to your hands, but due to copyright issues that part is something we can't really help on this forum... Should not be too hard though.

Oh, wow!

I remember I stumbled in to this article something like 15 years ago and I found it very fascinating! It seems that this project has needed a lot of dedication from lot of people. To be honest, it would be really nice to take a peek at the code at some point if you feel like you want to share it. The hardware part seems to be already very nicely documented. I believe showing such code publicly might even inspire people to do their own little retro projects.

I've been also doing some little experiments such as writing background task for MSX-BASIC to drive 8 servo motors using printer port data lines or doing RS-232 or PS/2 communication trough joystick port. I don't always know where the motivation to do such things pop up from, but I've been definitely inspired by this article among others.

As NYYRIKKI said, please do not modify your code to work around an emulator issue... it's the emulator that needs to be fixed, if that code is known to work on real hardware.

NYYRIKKI: The code had 40 char width and 80 char width versions, the screen photo was of a 40 char version but the programme "C-MRI111.BAS" was a 80 char version. I assume the club monitor was actually a TV set and the image wasn't that good in 80 char mode. It is, after all over 30 years ago! The code on the TaPRK site is the is the code I've tried to make work on WebMSX, and now succeded. I have only two verions of the C/MRI copied from DD1 floppies into PC hard drive. I have two X'press computers, but neither of those seem to have working floppy drive, or the floppies have gone bad. I have an external drive somewhere and I must try if that might still work. I do have plans of publishing the BAS files (although the code is not quite suitable for family viewing).

Manuel: I presently have no method of running the original software on my X'press. It is of little fun to me or anybody else if it cannot be played by WebMSX emulator either. I could not make it work on openMSX, so this was a good workarond, and I'm grateful for NYYRIKKI's comments of getting it running again. Modifying my one-off BAS programme to work on one emulator is much simpler and safer task than poking the WebMSX emulator, no? I only needed to modify 3 lines of code.

/pekka

I'd definitely like to know what the problem was running it in openMSX. Please let me know.