Neo6502 - hdmi problem, doesn't work

Started by olivierBautista, October 31, 2023, 04:26:02 PM

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I can't get the Neo6502 to work, :o
I can put the .uf2 file in the rasberry 2040 with the usb-A cable and my laptop, this is ok. ;D

I connect an hdmi screen, a usb keyboard and a 5v power supply to the usb C.

I connect :
For Oric emulator
pin 10 of UEXT connector (GPIO 25) to pin 24 of 6502 bus connector (IRQ) using external wire.

To use F12 as RESET button (both Apple ][ and Oric)
I connect pin 9 of UEXT connector (GPIO 26) to pin 40 of 6502 bus connector (RESET).

To use F11 as NMI button (Oric)
I connect pin 8 of UEXT connector (GPIO 27) to pin 26 of 6502 bus connector (NMI).

And the Neo3502 makes a little noise when I type on the keyboard, but nothing more. :'(

I've tried several power supplies (5v 3000 ma)

I also tried changing the positions of switch 1.....
I can't find much documentation on Internet.

What else can I do? Do you have any ideas?

thank you in advance for your answers.

Best Regards, Olivier Bautista


So what exactly doesn't work? Did you try with other uf2 files from our ftp here:

Is your monitor with native HDMI? Is a TV or monitor?
Technical support and documentation manager at Olimex


I don't have an image, 8)
I did take my files from this ftp repository. ;D
It's on a tv or on a vga monitor with an hdmi adapter, :-\
I'll try with a pure HDMI monitor. :D


We've received some reports of some HDMI-VGA adapters causing issues, try with native HDMI an report back.
Technical support and documentation manager at Olimex


Having same problem. :-(

Tried both directly connecting to hdmi tv and using hdmi usb pc adaptor both result in no signal.

I can hear the games that I loaded on NEO6502 running great, but I just can't see a thing.

Just to make sure I tested my hdmi tv and my hdmi usb pc adaptor with a PicoDV and both are working great with it.

I also tried a PiZero2W, Pi3A+, Pi4B, Pi5 and even a C64Mini and they all work great with both.

Perhaps its just a bad solder.

Does someone have some diagnostic software that we could load on the NEO6502 to test it's hdmi circuitry?


there are few reports that LG TVs do not sync with Neo6502 when used Apple emulators



I've got the very same problem: can't get an image from the HDMI connector of my NEo6502.

I've tried the following:

- use an HDMI2VGA adaptor on a VGA monitor
- connect directly to an HDMI monitor
- flash the apple2_800x600_400MHz.uf2 fw
- flash the firmware_usb.uf2 fw

I all the above cases, I'va also connected a USB keyboard, the Neo6502 emits a beep but no image is displayed.

Any other suggestion ?

Could my Neo be defective ?


The chances of defective board are zero. We test each board extensively and there is also an empirical with HDMI monitor.

How are the jumpers set?

Did you change video input medium on the monitor via the settings or the remote? Not sure if video resolution can be a problem but maybe try to check that too.

Can it be too long cable? Maybe try with shorter cables.

Some monitors might refuse to work with the Neo, make sure to join the Facebook group for the board and check similar discussions, there are few people mentioning similar compatibility problems, the Facebook group is here:

Here is filtered results with "HDMI" in search box, I see few results of people reporting problems with some monitors and displays that won't sync with VGA:
Technical support and documentation manager at Olimex