Search found 22 matches

by bola_dor
Sun Feb 25, 2024 3:10 am
Forum: The Welcome Area
Topic: Hello from Argentina!!!
Replies: 12
Views: 6098

Re: Hello from Argentina!!!

Hi, Sinclair QL was never officially launched or imported to Argentina. It's a very rare computer to find here and I only know about a very few here and less of them working like mine. At that time relationship with UK was broken because of the war. We had our stron contact with Sinclair's products ...
by bola_dor
Fri Mar 24, 2023 7:29 pm
Forum: Hardware
Topic: QL pico VGA, Need troubleshooting help
Replies: 12
Views: 2099

Re:(solved)! QL pico VGA, Need troubleshooting help

20230324_160155.jpg
20230324_160419.jpg
Finally!!
I miss the line linking the GND at https://github.com/holmatic/video_if_ql_vga
I just added a small wire, there are several GND pins at the Pico that can be used.




Thanks to everyone that took a minute to read and answer helping me so much..
by bola_dor
Thu Mar 23, 2023 8:11 pm
Forum: Hardware
Topic: QL pico VGA, Need troubleshooting help
Replies: 12
Views: 2099

Re: QL pico VGA, Need troubleshooting help

Connecting.png OK, I followed exactly this wiring but using a DB9 as input as I usually use a DIN->Db9 adapter to my OLD CRT. I 'll ad a wire Linking all three GND (all coming from different PSU, that scares me a little) and try again. I don't have another pico at hand but I'll get one or two. They...
by bola_dor
Thu Mar 23, 2023 3:27 am
Forum: Hardware
Topic: QL pico VGA, Need troubleshooting help
Replies: 12
Views: 2099

Re: QL pico VGA, Need troubleshooting help

The junction of all your 680ohm resistors don't appear to be at a ground (OV) pin on Pico. Either way you insert the Pico they appear to be connected to GP0 or GP16 ? Could we see underside of strip board to confirm the apparent wiring from the topside? Hi, they are connected to the GND pin at the ...
by bola_dor
Sun Mar 19, 2023 10:45 pm
Forum: Hardware
Topic: QL pico VGA, Need troubleshooting help
Replies: 12
Views: 2099

QL pico VGA, Need troubleshooting help

I come from. https://qlforum.co.uk/viewtopic.php?p=50691#p50691 trying not to get in the way of that thread I built my own board using a conventional Raspeberri PI pico, the long plate. 20230319_183224.jpg and I got this kind of result, GIF-230318_014332.gif please click to see in motion i have chec...
by bola_dor
Sun Mar 19, 2023 1:32 pm
Forum: Hardware
Topic: QL Pico VGA
Replies: 72
Views: 69842

Re: QL Pico VGA

Output channel levels are about 4v.. isn't that too high vor a VGA? If "output channel levels are about 4V" means RGB signals: Much too high. Did you forget the output resistors? Together with the termination resistors inside the monitor, they scale down the output voltage. Or did you mea...
by bola_dor
Sat Mar 18, 2023 10:25 pm
Forum: Hardware
Topic: QL Pico VGA
Replies: 72
Views: 69842

Re: QL Pico VGA

Hi all, Mine is a UK, 50Hz ISS 7 QL. I have a humble hanheld oscilloscope that I hope is good enough for this. I measured the QL output at the cable adaptor end without the Pico connected.. Signals are TTL level.. perhaps a bit high? I did ground the probe to the composite output with a perhaps too ...
by bola_dor
Sat Mar 18, 2023 4:47 am
Forum: Hardware
Topic: QL Pico VGA
Replies: 72
Views: 69842

Re: QL Pico VGA

Well I reviewed all connections, cleaned up the board looking for any flux residue.. added the rgb gnd connections to the dsub15 output (my old CRT doesn't like any pins soldered together) then wrapped anything whith tape and then aluminum foil with a wire I soldered to the db15 metal case and to gn...
by bola_dor
Sat Mar 18, 2023 2:08 am
Forum: Hardware
Topic: QL Pico VGA
Replies: 72
Views: 69842

Re: QL Pico VGA

You didn't even write which module you used. I'm sorry about that... I used the conventional raspberry Pi Pico, the larger one, and downloaded the firmware from the github page Are you aware that different binaries are needed for the (small) RP2040-Zero and the (larger) Raspberry? Did you keep the ...
by bola_dor
Fri Mar 17, 2023 6:01 am
Forum: Hardware
Topic: QL Pico VGA
Replies: 72
Views: 69842

Nedd troubleshooting help

Hi, I've just finished my QL pico VGA using a strip board (it didn't look so difficult) I guess I have some Sync problems. Screenshot_20230317_025359_Gallery.jpg Image is not steady with some horizontal jumps and the rainy band moves from top to botom, then the "signal?" Screen apears brie...