Problem with MSX VHD

페이지 1/3
| 2 | 3

By gabbafiend

Supporter (6)

gabbafiend의 아바타

12-03-2020, 15:53

Hi!
I’ve been reading threads on the forum for a while but this is my first post. The many in depth comments got me interested in the MSX and especially in MSX VHD. Thanks a lot for all the contributions!

Considering all the knowledge collected here, I wanted to ask if somebody on the forum might be able to help me with a technical problem related to the MSX VHD…

It took some time but I finally got all the parts needed for playing VHD games:
MSX HC-7
VHD Player Victor HD-7900
IF-7900 Interface
Aiwa Data Recorder DR-20

I also have two VHD games, Road Blaster and Thunder Storm (both complete with data tape).

The MSX HC-7 is connected…
- to a Sony CRT via a RGB 21-pin cable,
- to the VHD Player via a 13 pin DIN connector, and
- to the Aiwa Data Recorder via the necessary cable (I forgot the standard’s name).

Everything seems to be working alright, although the VHD Player is not exactly in perfect condition. But for some reason the superimpose feature does not seem to work as intended.

Here’s what I’m doing:
I put the Road Blaster or Thunder Storm VHD into the VHD Player, turn on the MSX and start MSX Basic. Then I let the data tape run via the Aiwa Data Recorder and type in “cload”. Usually either of the two games is recognized right away and I press F5. After a few minutes of loading the game will start and that is when the problem occurs.

The menu generated by the MSX is not superimposed on the video from the VHD player. I only see the pixel graphics generated by the MSX but not the video from the VHD player.

However, the VHD player recognizes the commands from the MSX. I can start and control the games. I know this because if I disconnect the MSX from the CRT and instead connect the VHD player to the CRT via RCA / Cinch, I can see that the VHD Player responds to the keys I press on the MSX. Of course, this way I only see the animation and non of the menus or other in-game pixel graphics will be shown. But I can play the game. This goes for both Road Blaster and Thunder Storm.

The MSX HC-7 is in very good condition, considering its age. I don’t think it’s a problem with the Aiwa Data Recorder as I’d the chance to load the games with a different data recorder. The result was the same. The 13 pin DIN connecter is rather new. The RGB 21-pin cable seems okay, too. I also connected the MSX to the CRT via RCA / Cinch but again the same result.

If it’s a hardware related problem, I can only think of the VHD Player (which is showing its age more than the other parts) or the IF-7900 interface module (but the VHD Player reacts to the commands from the MSX transferred via the module properly).

Or am I missing something?

Unfortunately I don’t have the manual for the IF-7900 interface. Is there maybe the need to activate the superimpose feature separately?

If somebody has an idea what could be the problem, I’d be truly grateful!

Login or 등록 to post comments

By mars2000you

Enlighted (5635)

mars2000you의 아바타

12-03-2020, 17:41

There's an MSX-BASIC extension inside the IF-7900 interface - https://www.msx.org/wiki/Victor_IF-7900

It's the part you are missing, a 8kB ROM, there's probably an instruction like CALL IMPOSE as it's the case with Pioneer computers and P-BASIC - https://www.msx.org/wiki/P-BASIC

If you could make a dump of this cartridge, it would be helpful to find the MSX-BASIC instructions of Victor BASIC - https://www.msx.org/wiki/Victor_BASIC

Also dumps of the ROMS (BIOS ROM and firmware ROM) of the Victor HC-7 are welcome, especially to allow emulation of this machine.

See the first message in this thread for details about how to dump ROMS: https://www.msx.org/forum/msx-talk/emulation/dumpingreverse-...

By Manuel

Ascended (16698)

Manuel의 아바타

12-03-2020, 20:29

For the MSX to superimpose, the video signal from the VHD player needs to go through the MSX... does that happen via the 13-pin cable??

By sd_snatcher

Prophet (3296)

sd_snatcher의 아바타

12-03-2020, 21:55

I hope you're not one of those smart spambots that post elaborate questions and then disappear under a load of SPAM. Smile

It's quite a rare setup you have, so you'll need to have some patience as most of us won't have the specific experience required for this machine. It will help *a lot* if you can dump the machine and interface ROMs as requested by mars2000you.

I suspect of your RGB21 cable. Are you sure that it has all the required pins? Most economical RGB21 cables only have the wires required for output. I believe your case will require a complete cable, that has both the input and output pins connected. Compare the connected pins with the pinout available here.

My suggestion is: first, check if the superimposer is working correctly with the MSX in standalone mode, without any of the VHD gear connected. Theoretically, the built-in "Tiny Joygraph" editor can be used for that.

Also, if you have the manual for the Victor HC-7, please scan it and post it at this article. This will also provide more info so people can help you.

By Manuel

Ascended (16698)

Manuel의 아바타

12-03-2020, 22:21

sd_snatcher: the RGB21 is only between MSX and monitor, isn't it? And I think he needs video going from VHD player to MSX... so MSX can superimpose itself on it. That must be going through that 13-pin cable, as far as I can see. (There don't seem to be other connectors on the interface cartridge either.)

By mars2000you

Enlighted (5635)

mars2000you의 아바타

12-03-2020, 22:30

Manuel: the Victor HC-7 has an RGB21 input/output connector and a Composite monitor 5-pin DIN 41524 for monitor output - the 13-pin cable is for the connection with the VHD player.

By sd_snatcher

Prophet (3296)

sd_snatcher의 아바타

12-03-2020, 23:25

There's also a knob in the back labeled "Balance Mix", that goes from S to P. I suppose that this means from "SuperImpose" to "Picture"?

By sd_snatcher

Prophet (3296)

sd_snatcher의 아바타

12-03-2020, 23:31

This other image from the Victor HC-60 manual suggests that the image cable should be connected to the RGB/Video TV, and it's the TV that must be capable of superimposing.

By sd_snatcher

Prophet (3296)

sd_snatcher의 아바타

12-03-2020, 23:44

What the heck is that "VTR Record" connector supposed to do? It's also present on the HC-0602S module, and it wouldn't make sense as an output since the HC-5, HC-6 and HC-60 all feature the DIN5 video/audio output connector.

By mars2000you

Enlighted (5635)

mars2000you의 아바타

12-03-2020, 23:46

Better to give the last link this way (MRC site issue) :

https://www.msx.org/wiki/Composite_monitor_(5-pin_DIN_41524)

You need to copy and paste in a new tab (because it appears broken in the forum)

By sd_snatcher

Prophet (3296)

sd_snatcher의 아바타

12-03-2020, 23:55

The link in my post is working fine for me, after I encoded the problematic chars. Can you please test it again?

페이지 1/3
| 2 | 3