MSX HDMI mutlimedia card | MSX Resource Center (صفحة 7/57)

بواسطة maxis

Champion (512)

25-03-2014, 18:35

o.geerdink wrote:

Count me in for one.

Ok. Fully assembled +1.

بواسطة maxis

Champion (512)

25-03-2014, 18:43

Brief status:
The slot interface is fully debugged, VDP model (light & simple 9938 w/o sprites & commands) is finished but has quite a few internal bugs, which don't allow to have a demo for now. Debugging is ongoing.

Short question to the MSX specialists & professionals:

Could you, please, confirm or deny that CPUCLK=3.57 MHz on the MSX slot under any conditions (regardless the TURBO mode).
Thank you

بواسطة Manuel

Ascended (19463)

25-03-2014, 21:18

Yes, it is per the MSX standard.

بواسطة Denus

Expert (120)

25-03-2014, 23:06

I wonder though why this pcb has not been made as a stand-alone device, with a wired cartridge to connect it to the MSX machine when required. I mean: this module will have a lot of cables connected to it, so it's more convenient imo to have this device in a box (somewhat like the Onechip MSX design-wise) with a (detachable) wired cartridge for the MSX slot connection.

I know this is not an option as this point, but could maybe be a good point for similar projects in the future...

بواسطة maxis

Champion (512)

26-03-2014, 09:59

Denus wrote:

I wonder though why this pcb has not been made as a stand-alone device, with a wired cartridge to connect it to the MSX machine when required.

The reason for that is purely economical and circumstances. Initially this card was a multimedia extension card for the mobile robot. Then the project was transformed into the extension card for MSX or a standalone game machine too.

Now the PCB has both - edge connector and the 50 pin header next to the edge connector for the stacking.

Also the card is not that huge. It measures approx 10x13cm. Size of the classic floppy controller (VY0010 or FD051).
HDMI connectors are placed near by the edge connector to reduce the moment of force applied to the HDMI cable (thick and rigid). The other connectors are also located on the side edges. Top is for the SD cartridge, CMOS battery and USB. connector.
In the typical configuration it is assumed having one HDMI, one TOSLINK/Analog stereo out. Not that bad for an ordinary cartridge. IMHO, aesthetically this wouldn't spoil too much the look of your precious machine.

Just to give an idea, this is how it looks when plugged into CX11 with the VY0010 behind (you can see the floppy cable)

بواسطة maxis

Champion (512)

26-03-2014, 10:02

Manuel wrote:

Yes, it is per the MSX standard.

Thank you, Manuel.

بواسطة Denus

Expert (120)

26-03-2014, 10:12

True Maxis: the pcb is indeed quite small and was initially not designed for the purpose as a stand-alone MSX board.
Note: it was only a thought, eventually for further projects.

بواسطة maxis

Champion (512)

26-03-2014, 10:57

Denus wrote:

Note: it was only a thought, eventually for further projects.

I totally agree that if the majority would prefer having a break-away small PCB going into the slot and the external box combi, this would suit me well too (no difficult routing to comply with MSX cartridge mechanics and board outline).

For the moment, however, this was an attempt to make a full size MSX cartridge (personal preference).

بواسطة Grauw

Ascended (10768)

26-03-2014, 12:40

Manuel wrote:

maxis wrote:

Could you, please, confirm or deny that CPUCLK=3.57 MHz on the MSX slot under any conditions (regardless the TURBO mode).

Yes, it is per the MSX standard.

If I switch on my 7MHz circuit on my Philips NMS8245, or run the One Chip MSX in 10MHz mode, the SCC sound will be pitched up and the clock output frequency definitely increases. So even though it may not be according to the MSX standard, it does happen in practice.

بواسطة Manuel

Ascended (19463)

26-03-2014, 12:52

On a turboR, which is of course official, it is according to the standard, so the usual 3.5MHz.