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Re: My Dragon cartridge boards (actually work!!!)

Posted: Fri Mar 01, 2013 4:42 pm
by Rink
How's this?

Image

Re: My Dragon cartridge boards (actually work!!!)

Posted: Fri Mar 01, 2013 5:26 pm
by zephyr
That's not bad, but it would be better if you could take another photo from above, with the camera directly facing the board (so we can more clearly see all the interconnecting tracks).

Re: My Dragon cartridge boards (actually work!!!)

Posted: Fri Mar 01, 2013 5:59 pm
by Rink
Would it be easier if I just post the PCB images from the design software? Waiting on a new power supply for my laptop but I suspect it'd be a lot clearer than trying to make out black tracks between a black ground fill under a black solder mask. :)

Re: My Dragon cartridge boards (actually work!!!)

Posted: Fri Mar 01, 2013 10:24 pm
by zephyr
Rink wrote:Would it be easier if I just post the PCB images from the design software? Waiting on a new power supply for my laptop but I suspect it'd be a lot clearer than trying to make out black tracks between a black ground fill under a black solder mask. :)
No. A quick photo taken from the correct angle would suit me just fine! :)

Re: My Dragon cartridge boards (actually work!!!)

Posted: Sun Mar 03, 2013 3:32 pm
by zephyr
Please place the PCB in the center of an A4 sheet of white paper, and take a photo with the camera directly facing the solder side. This quick, simple task is all I'm asking for. :)

Regards,
Steve

Re: My Dragon cartridge boards (actually work!!!)

Posted: Sun Mar 03, 2013 4:40 pm
by Rink
zephyr wrote:Please place the PCB in the center of an A4 sheet of white paper, and take a photo with the camera directly facing the solder side. This quick, simple task is all I'm asking for. :)
Lol. Will do mate.

It's pretty gloomy here today so will have to source a few extra lights and things - or a better camera. :)

Re: My Dragon cartridge boards (actually work!!!)

Posted: Wed Mar 06, 2013 9:43 am
by Rink
Any use to you? Not that it matters, it's as good as it's going to get. ;)

Image

Re: My Dragon cartridge boards (actually work!!!)

Posted: Wed Mar 06, 2013 12:41 pm
by zephyr
That's perfect. Thanks! :D

Re: My Dragon cartridge boards (actually work!!!)

Posted: Wed Mar 06, 2013 1:53 pm
by Rink
Cool. :D

Re: My Dragon cartridge boards (actually work!!!)

Posted: Wed Mar 20, 2013 10:26 pm
by Rink
GOD DAMN!!!

I've just spent a few days trying to make a second (slightly better) ROM programmer, and in the process discovered a mistake on my boards. I forgot to check if the NAND gates I was using needed a pull up resistor to turn 0s into 1s. It turns out that they do - which means that OE* on the rom/ram chips was always getting enabled.

This is interesting in two ways: firstly, it means that those Alliance SRAM chips are super good at detecting movement on WE* and initiating a write cycle even when OE* goes low 20ns later. And secondly, it's a good reason why I couldn't get the Dragon 32 to write to a 28 series EEPROM even though it looked like it should...

With a resistor in place, the Dragon CAN write to those roms and so now I have a non-volatile RAM pack for the Dragons. It also means that the little trick of using DrBinCas to load a ROM image from tape makes the Dragon 32 into a rom programmer... Meaning I didn't need to spend the last few days building another programmer. :roll:

Life is funny sometimes.