New Atom owner (soon)

[myelin]

After staring at it on eBay for a couple of weeks, I finally cracked and bought the 200 euro Atom from backtoyourpast (pricey, but out of the Atoms I've seen whose owners will ship to the USA, it seemed bearable). So... I expect to be an Atom owner once it arrives in San Francisco

[Elminster]

I am waiting for Roland to reinvent his Atom design. 200 euros seems a bit steep.

Failing that I hope to magically acquire one.

[waltermixxx]

200 euro's for an Atom is not bad,
I've seen it as high as $800.00 or so for an Atom.
or no Atom's at all. Good for you for getting one.

I finally got one for myself as well. And I love it.
Upgraded it to 32k, and added a coco 2 composite video board to it,
as a colour board.

Please make sure you get one of those MMC interfaces for it as well,
very reasonably priced and totally necessary for reliving some of those
gaming memories.

Congrats on your purchase, Bottom line, Congrats...

Cheers.

[hoglet]

After staring at it on eBay for a couple of weeks, I finally cracked and bought the 200 euro Atom from backtoyourpast (pricey, but out of the Atoms I've seen whose owners will ship to the USA, it seemed bearable). So... I expect to be an Atom owner once it arrives in San Francisco

This is actually a very good price for decent Atom, and the Issue 5 atom is definitely the one to have.

What's you plan in terms of extensions?

AtoMMC2 and some kind of RAM/ROM board are the two "must-have" Atom extensions.

For a nice, clean video output from the 6847 I use a custom scan convertor which works very well, and doesn't require any mods to the Atom:
https://github.com/hoglet67/AtomVGAWing
viewtopic.php?p=58741#p58741

Dave

[myelin]

What's you plan in terms of extensions?

Not sure yet! AtoMMC2 seems like an excellent start.

I like the look of your scan converter. Also, do you think your RGBtoHDMI hardware could be adapted to work here? I guess you would need comparators on the inputs...? I'm still figuring out how the whole Y/PA/PB video thing works.

[8bitkick]

After staring at it on eBay for a couple of weeks, I finally cracked and bought the 200 euro Atom from backtoyourpast (pricey, but out of the Atoms I've seen whose owners will ship to the USA, it seemed bearable). So... I expect to be an Atom owner once it arrives in San Francisco

Hey congratulations I've just been getting my Atom running too. I imagine there aren't many in California!?

Until you get your MMC this might be useful. I just saw your post which prompted me to get in online...

[myelin]

Until you get your MMC this might be useful. I just saw your post which prompted me to get in online...

Thank you! Yes, that'll be super useful! Are you bringing your Atom to VCF? There's a slight chance that mine might arrive in time...

[hoglet]

Also, do you think your RGBtoHDMI hardware could be adapted to work here? I guess you would need comparators on the inputs...? I'm still figuring out how the whole Y/PA/PB video thing works.

From a timing point of view I'm sure it could be made to work.

The only problem is the Y/PA/PB signals are relatively low voltage swing and tri-level (with some redundancy).

Figure 10 in the 6847 data sheet best explains this.

In the FPGA I use the differential LVDS I/O cells rather than external comparators. Each of PA and PB uses a pair of LDVS I/O cells, which allows comparison against two different thresholds. This gives you the tri-level sensing. The Y signals is clamped with a proper back-porch clamp circuit to restore the black level.

I'll check the DipTrace schematic and PCB design into github this morning.

Dave

[8bitkick]

Until you get your MMC this might be useful. I just saw your post which prompted me to get in online...

Thank you! Yes, that'll be super useful! Are you bringing your Atom to VCF? There's a slight chance that mine might arrive in time...

I was planning to bring my Atom. I can start another thread as we need to sort out logistics for the day...

[myelin]

The only problem is the Y/PA/PB signals are relatively low voltage swing and tri-level (with some redundancy).

Figure 10 in the 6847 data sheet best explains this.

In the FPGA I use the differential LVDS I/O cells rather than external comparators. Each of PA and PB uses a pair of LDVS I/O cells, which allows comparison against two different thresholds. This gives you the tri-level sensing. The Y signals is clamped with a proper back-porch clamp circuit to restore the black level.

Oh, I see now -- you're using the differential inputs to compare against voltage references, which explains the AH/AL signal names So you need quite a few more inputs into the system than when just reading an RGB signal.