MSX Sharp Hotbit HB8000 help

[CleversonSA]

Hi,

I have a HB8000 Sharp Hotbit MSX device that I´ve changed the original VDP to the pico9918. I´ve modded the device to embed an cheap VGA-HDMI converter.

At first days of used, all things worked fine (no more A/V cables, just a HDMI), but I´ve started to get a messed up screen like the VRAM was corrupted. I´ve reverted back to the original TMS VDP and all things worked fine. I tried new firmware, but nothing works anymore (just a messed up screen).

Is there a problem when using a VGA-HDMI converter with RP2040 pico9918?

Regards.

[visrealm]

Hi,

There shouldn't be any issues with the VGA-HDMI converter. Though, there is a native HDMI dongle now which is a cleaner solution again.

Only two things I can think of:

1. Power - how is your VGA-HDMI converter being powered? It could potentially affect the system stability (this is something that took me a few iterations on my native HDMI solution).
2. Connection - is the PICO9918 seated firmly with the converter installed? It's not being knocked loose?

You can get the PICO9918 HDMI dongle on Lectronz if you're interested.

CHeers
Troy

[CleversonSA]

Hi,

Thanks for response. The MSX board and the VGA-HDMI converter is powered by the same PICO ATX PSU. I´ve checked the required voltages (+12, -12, 5v) for both devices. May be a ground loop problem?

The PICO9918 connection is seated firmly at the main board. The connection to the VGA-HDMI is provided by a fresh new flat ribbon cable.

I´ll try re-wire everything, test a new Pico 2040 and check again.

Cheers