Edited my earlier post, Chad - thanks.
Nicely done with this one. Astonishingly, I seem to have the correct footprints for the bus connectors I have in stock, so I'll bolt it together sometime soon (the VGA version) and see if it ticks. Admittedly, the 14MHz oscillator block has the wrong footprint; I'll have to dead-beetle that, I think.
Neil
p.s. ask me about a design for a rotating nixie clock sometime...
VGA Serial Module
Re: VGA Serial Module
So, the line timing is correct (apart from an enabling link I missed on the third counter stage - I'll post a list of changes and a new schematic when I'm done) but it looks a little flaky, so I think I have a dry joint to find.
TBC...
TBC...
Re: VGA Serial Module
Well, the line sync is fine, the right length and at the right timing... but when it comes to field syncs I was kind of hoping for just the one, not the dozen or so I'm getting. I need to check my counter logic, I fear.
Neil
Neil
Re: VGA Serial Module
Update:
Just soldered my latest version of the Serial VGA board. And it worked the first time! Here I have the (new) Arduino connected to it. It is super easy to interface, as was the point of this project. I plan on testing it with my SBC sometime later.
The big changes are:
- I removed PS/2 Mouse support, though it was just 2 pull-up resistors anyways.
- I removed 2 character ROM bank pins, so it is now down to only 4 ROM banks.
- I added support to make the RAM socket into a FlashROM programmer! That was the main reason for this new version.
To do this, you change the DIP switches appropriately, plug the SST39SF010 into the RAM socket, then start writing to memory just as if it were RAM. There is of course unlocking sequences and all that involved, but the idea was to allow a newbie to use this device for keyboard, audio, video, and a programmer. In fact, the main reason for this feature is to program the video and character ROMs for this very device!
Warning, I haven't tested the programming aspect of it yet, will be doing that soon. Will report back when when it is fully tested.
Thanks!
Chad
EDIT: Whelp, oops. I didn't realize that I needed the FIRST 32KB of available space to program the ROMs. I had designed it to program the LAST 32KB instead! That'll change things
Working on the next revision already, this will have a dedicated ROM programming socket yet still fit on that little 4"x4" board. Will update when I have more.
Just soldered my latest version of the Serial VGA board. And it worked the first time! Here I have the (new) Arduino connected to it. It is super easy to interface, as was the point of this project. I plan on testing it with my SBC sometime later.
The big changes are:
- I removed PS/2 Mouse support, though it was just 2 pull-up resistors anyways.
- I removed 2 character ROM bank pins, so it is now down to only 4 ROM banks.
- I added support to make the RAM socket into a FlashROM programmer! That was the main reason for this new version.
To do this, you change the DIP switches appropriately, plug the SST39SF010 into the RAM socket, then start writing to memory just as if it were RAM. There is of course unlocking sequences and all that involved, but the idea was to allow a newbie to use this device for keyboard, audio, video, and a programmer. In fact, the main reason for this feature is to program the video and character ROMs for this very device!
Warning, I haven't tested the programming aspect of it yet, will be doing that soon. Will report back when when it is fully tested.
Thanks!
Chad
EDIT: Whelp, oops. I didn't realize that I needed the FIRST 32KB of available space to program the ROMs. I had designed it to program the LAST 32KB instead! That'll change things
Working on the next revision already, this will have a dedicated ROM programming socket yet still fit on that little 4"x4" board. Will update when I have more.- Attachments
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