WANTED : DRUMULATOR

 

** DEAD OR ALIVE **

Keyboard for OMEGA MSX Computer : it works!

It took me much less time than expected to be able to interact with the OMEGA board:

Before testing my USB to keyboard adapter board, I had tested the reception of codes from the USB keyboard. So I knew it was working. But I still didn't know how MSX BIOS scans the matrix keyboard.

After a few attempts and oscilloscope tests, I was able to send 'things' to OMEGA. But obviously not the right codes. After having researched the official codes of the MSX keyboards, I realized that the BIOS installed on OMEGA manages the Japanese keyboard! Why not!...

My first goal being to be able to type a little Basic program and run it, I decided to code the essential characters. First, the alphabet:

I am totally amazed at how easy it was to turn on my USB / OMEGA keyboard interface. I didn't have any issues with the design of the board, everything worked right from the start. Coding the software of the small STM32G0 processor was really very easy with the STmicro IDE.

For now, the coding is more of the quick and dirty type but it works very well!

On the way to my first "Hello World" program ;-)

MSX OMEGA & CARNIVORE 2

The MSX OMEGA main board:

So far all I have managed to do with the OMEGA MSX board is boot to the free C-BIOS bios: 

The problem is that C-BIOS is a really minimalist bios that only allows you to start an application on a cartridge. 

Now, I find myself with two problems.

The first is that I now need to test my USB keyboard adapter on the OMEGA motherboard. However, I do not have any game cartridges. Under these conditions the system does not allow me to do anything.

As Sergey Kiselev specifies, Omega is compatible with the Sanyo PHC-23J machine. So I recreated a bios starting from the basic ROM and the extended ROM of this system. Obviously, I have no commercial rights to this ROM, but the use is strictly private and as a development resource in my case.

And voilà: 

I am now under Microsoft Basic. I will therefore be able to continue the development of my USB interface and particularly the management of signals with the OMEGA PPI.

I remember in 1988, I joined a company that still had a small microcomputer running Microsoft Basic. It was used to program the very fashionable LED display strips at the time. I had just turned on this machine and had fallen the same way directly on the Basic's screen. I don't remember if this machine was an MSX type or not. I don't remember the manufacturer either. Regardless, 33 years later, I'm here again :-)

And the question is: does the Carnivore 2 card work under this environment?

Is that enough for you as an answer?

Carnivore 2 works exactly as described in the documentation. For the moment I have not prepared a FLASH card so the list of files is empty. 

There is still a bit of work to be done before I can use my Carnivore 2 card for mass storage. Indeed, the Flash card must be prepared through the Carnivore application. Besides the fact that I will only be able to do this when my keyboard interface is working, it seems that some files must also be installed on the Flash card (auto-start mode). I don't know if this is absolutely necessary but whatever. This procedure can only be done through a floppy disk drive. I now need to acquire a floppy interface to complete my system.

It's really nice to see this system come to life step by step.

Keyboard for OMEGA MSX Computer : no 'magic' smoke :-)

Until now, I have carried out my developments on this USB keyboard interface by powering the board using a laboratory power supply. As I have pretty much finished the software embedded in the STM32 processor, it's time to see what it looks like on the OMEGA board.

This is what the final assembly looks like:

The interface LED responds well to pressing keys on the USB keyboard. It remains to be seen if this works well with the OMEGA board.

As a USB keyboard does not really take the specific keys of the MSX keyboard, I planned the use of specific keys of the USB keyboard like ALT, CTRL etc ...

HUMOR...

 When you absolutely have to find a solution:

Image of the last century?

No! Image taken in June 2021. 'Provisional' electrical installation of French Travelers, Nantes, France. No protection, no meter, free electricity and ... not even tourist taxes!

If the 'modern world' bothers you, take back the power ;-)

Audio Direct Box prototype

I had to wait more than a month this time to receive the printed circuit board of my Audio Direct Box :

There really is a persistent problem with global distribution channels :-(

The problem now is to recover the components necessary for the complete construction of the first 'real' prototype.

To be continued...

Sergey Kiselev MSX OMEGA computer and... a keyboard for it.

 Sergey Kiselev developed some time ago an MSX2 compatible computer :

This is one of the boards that I buid. Building this kind of retro-computer costs a certain price, in particular because of the connectors which are also of the MSX type and are not very affordable today.

In fact, I hesitated to build the keyboard that Sergey developed for this OMEGA, thinking of using a standard and cheaper keyboard either PS / 2 or USB.

Obviously, the most common models today are of the USB type. So I developed a small USB interface on one side and parallel on the other to interface with the keyboard bus of the OMEGA board :

This interface uses a specific processor which manages the USB protocol to which I have added an STM32G0 type processor for the decoding of the USB frames intended for the OMEGA board.

The documentation of the USB management circuit being very ... light, I had some difficulties in retrieving the key code from the USB keyboard.

But here I am:

The right part of the ST IDE displays, among other things, the value of the Key variable, corresponding to the value 0x14. I actually hit the 'A' key on the keyboard, which matches well the 'Q' code on the standard keyboard. And yes, I use a French keyboard ;-)

The code is not very well written yet. All I have to do now is manage the sending protocol to the OMEGA board and I will finally be able to interact with this computer. So far I've only managed to get the init screen, which isn't bad :-)