jdgabbard wrote on Tue, 19 May 2020 06:32

Creator of the G80-S Micro Computer and 'Porter' of TinyBASIC 2.5g

Hi,
another issue.
Is there possible to compile the tinyBASIC for MSX and load it once C-BIOS started?
I know that N8 Home computer is not an MSX standard computer but he has C-BIOS and BASIC, It could be possible to do anything similar with the OMEGA HOME COMPUTER, when using a c-bios firmware?

let me know.
regards.

jdgabbard wrote on Tue, 19 May 2020 06:32

oard down to all of the pieces (to align it), then making small tacks with some spare filament and a dedicated soldering iron tip. Once these tacks are in place you can either weld it with a 3d pen, or use epoxy. Then sand smooth, primer, and paint.

Of course to me, this sounds more aligned, beauty result and clear plan. we can also my do my suggestion leaving more slack between the pieces, to permit alignment, then glue, sand and paint.
Regards.

It's very possible. Though TB 2.5g (my custom version of TB) is much less feature rich as MSX Basic. Given the capabilities of what the MSX has already, I'm not sure why you'd want to, unless it was to have more user space available. But even then, with the extra routines you'd need to make it useful to the MSX, you probably wouldn't gain much user space once you factored in the way you program TB versus MSX basic.

With a PAL bios some games like IKARI are shown wrong and some like Aleste are slow even playing music.
Does it mean the PAL circuit of my Omega runs as should but I don't have a PAL TV or maybe anything connected to RGB is not "PAL".

I hope someone can help me.
I don't have a PAL monitor (neither a NTSC one).
At the beginning I tested the Omega with NTSC configuration and a composite to SCART cable connected to a standard LED TV.
Then I changed the configuration on the board and tested it with PAL, but nothing was displayed on TV.
After that I knowed that the RGB connection was actually better image and built a cable from DIN-8 to SCART.
Then I was able to display images even if PAL or NTSC configuration was implemented.
following the Sergey instructions some components must be removed, replaced and some jumpers must be swapped.
Ok,
Now I would like to know how it works in deep, because even if I left JP3-JP4 in any possition, even if I left all the components like Y3 installed, and even if left R9 and C91 in old values, I can display images everytime on my TV and just the BIOS kind switches what is the working speed.
With a PAL bios some games like IKARI are shown wrong and some like Aleste are slow even playing music.
Does it mean the PAL circuit of my Omega runs as should but I don't have a PAL TV or maybe anything connected to RGB is not "PAL".
To leave my building instructions as clear as possible I would prefer everyone soldering all the components what don't disturb.
regards

PAL BIOS configures VDP for 50 Hz refresh rate, while NTSC BIOS configures VDP for 60 Hz. This happens regardless of JP5 and JP6 jumper settings. These jumpers only switch the timing and the video output standard for the CXA1645 encoder, and I think they only impact the S-Video and composite video, not the RGB. (By the way, you wrote JP3 and JP4. I assume it is a mistake. These jumpers have nothing to do with PAL or NTSC. They select between V9938 and V9958 and must match the VDP, or bad things will happen).
On each screen refresh VDP generates an interrupt, and that interrupt is commonly used for synchronization. So if you run a game designed to work with 60 Hz NTSC system, it will appear to be sluggish on 50 Hz PAL system. And vice versa, if you run PAL game on NTSC, it will appear to run faster.

Then I changed the configuration on the board and tested it with PAL, but nothing was displayed on TV.

I know that the little LCD screen I purchased a while ago for project work with composite input is auto-switching between PAL and NTSC frequencies, it's possible that the screen you're using isn't one that switches automatically? Or if the game's programming relies on timing from the NTSC side of things and setting the timing to PAL causes it to stumble, since they're both japanese (NTSC) games.

Question/suggestion for Jordi: which chip is superior, the https://en.wikipedia.org/wiki/Yamaha_YM2608 or the https://en.wikipedia.org/wiki/Yamaha_YMF278 from moonsound? ...

I will try to decrease the value for resistor R4 on the FMPAC board and let you know (I discovered the schematic shows 4k7 but the silkscreen 2k2)

regads
J S

Hi all,
Some people here reported problems with few cartridge games and the Omega home computer.
Would anyone confirm any of those games are working with its Omega (only cartridge version)?
It seems that is focused on 32K games because most of 16K and megarom are working.


The Goonies: screen with few green lines, then reboot. Once and again, and again...
Knightmare: the game starts but all graphics and tiles are wrong.
roller ball (de halm 16KB): starts directly to msBASIC.
raid on bungelin bay (de sony, 32KB): a half of the screen on blue and the other black.
Pacman: black screen.

Kind regards.
J.S. MSXmakers

Hi All,
I have fixed the problem.
There was a bug on the slot dir gal code.
The new code can be downloaded from ow is corrected on the Sergey's github.

Jordi,

Your O4MEGA ram expansion module is nice idea but the board is interfering with one of the
keyboard supports. Could you modify it so it would have a hole in the correct place?

Best regards,
Bo/

If someone want to know it I added an F4/FMPAC to my Omega computer and now some games sound actually nice.
As I would like to save the cartridge slots I didn't added the eprom chip to this board and just added the binary file to the current OMEGA firmware.
It just need to connect +-12v power source to JP1 on FMPAC board, and AMP/GND connection to pin 2,4 of U48 in the Omega motherboard.
Now Aleste sounds fantastic but a little bit low.
I will try to decrease the value for resistor R4 on the FMPAC board and let you know (I discovered the schematic shows 4k7 but the silkscreen 2k2)

regads
J S

Disregard. I had misunderstood the directions. I thought the Keyboard RN1 had been removed and moved over to the PCB on Mainboard v1.1. However, I then realized that it was still needed. All works great now, and runing MSX2+_int_NTSC flawlessly.

Now if only my SD-512 that I dumped quite a bit on several years ago actually worked, I'd be in heaven.

jdgabbard wrote on Wed, 05 August 2020 15:50

Disregard. I had misunderstood the directions. I thought the Keyboard RN1 had been removed and moved over to the PCB on Mainboard v1.1. However, I then realized that it was still needed. All works great now, and runing MSX2+_int_NTSC flawlessly.

Now if only my SD-512 that I dumped quite a bit on several years ago actually worked, I'd be in heaven.

Does your SD-512 itself not work or have you found a compatibility issue with it and the Omega? I've got one and haven't tried it yet, but I had wondered how it would interact with the onboard memory map and how it tries to run NEXTOR.

Jordi,

Since I got my Omega running the other day I got to thinking about the FM-PAC. And it may be easy to simplify the design further, omitting the +12v rail. Looking at the schematic, it appears that it's only needed for the amplifier. But other designs for computers often use just a 5v rail, such as with the schematic below. Of course, it would need a few changes, such as the 10uF cap and 4.7k resistor to be tied into the Omega's audio circuit. But that is trivial. Have you though about this?