Jump to content
Bryan

The UAV Rev. D Video Upgrade Thread

Recommended Posts

Been looking at the 1200XL's video. Atari added a color boost circuit to the 1200 series which makes the burst about half the amplitude of the chroma across the rest of the line. This has the same effect as cranking the Color control on the monitor since the burst defines the reference amplitude. The burst is extraordinarily weak, being about 1/3 of the proper amplitude (@ ~100mV). All other chroma is about 200mV. The chroma is also messy looking. This weak burst means the monitor will increase its internal chroma gain to compensate which causes a lot more color artifacts.

 

In addition, the sync signal is also very weak so some modern sets won't sync at all and the darker shades of gray probably won't show up. Atari really botched this one, but I do want to experiment with the color boost concept.

Share this post


Link to post
Share on other sites

Been looking at the 1200XL's video. Atari added a color boost circuit to the 1200 series which makes the burst about half the amplitude of the chroma across the rest of the line. This has the same effect as cranking the Color control on the monitor since the burst defines the reference amplitude. The burst is extraordinarily weak, being about 1/3 of the proper amplitude (@ ~100mV). All other chroma is about 200mV. The chroma is also messy looking. This weak burst means the monitor will increase its internal chroma gain to compensate which causes a lot more color artifacts.

 

In addition, the sync signal is also very weak so some modern sets won't sync at all and the darker shades of gray probably won't show up. Atari really botched this one, but I do want to experiment with the color boost concept.

 

Wow. You're not kidding. I'd be interested in seeing what Bob Wooley's ClearPic mod does to that, and also how the UAV output compares on the scope.

Share this post


Link to post
Share on other sites

Wow. You're not kidding. I'd be interested in seeing what Bob Wooley's ClearPic mod does to that, and also how the UAV output compares on the scope.

UAV samples of the same signals plus the NTSC and PAL standards. For NTSC, burst is specified as +/- 20 IRE and for PAL it's +/- 21.43 IRE. For NTSC, 1 IRE is 7.14mV. For PAL it's 7mV.  So, the NTSC burst is ideally 285.6mVp-p and PAL is 300mVp-p. UAV (Rev D) is about 288mV which is close enough. Sync is defined as 286mV for NTSC and 301mV for PAL. UAV is about 312mV because NTSC has a separate black level at 339mV.** This means LUM 0 is a touch above standard black for PAL and a touch below it for NTSC. A LUM of 1 is above black for both. Most Atari video is far enough away from the standard that either the lowest shades are lost, or the background is perpetually gray.

 

** The blank level isn't technically required by consumer equipment and although Atari included a pin for it in TIA, they didn't end up using it to create a separate Luma step. Instead, they sometimes used it to implement a chroma boost like the 1200XL has.

Share this post


Link to post
Share on other sites

By the way, you can order UAVs specifically for 1088XEL use and they'll come with down-facing pins instead of the terminal.

Share this post


Link to post
Share on other sites

Can you give a link for the 2mm jumpers please?

It uses the 800XL/XE settings.

 

post-3606-0-54203400-1483035683_thumb.pn

 

 

EDIT: Oh, you mean where to get them? Search for 2mm Shunt. Did I forget to include them?

 

http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/959102-0000-DA

http://www.ebay.com/itm/20-Micro-2mm-Jumpers-Shunts-SCSI-Laptop-Jumper-shunt-/350557475054

Share this post


Link to post
Share on other sites

It uses the 800XL/XE settings.

 

post-3606-0-54203400-1483035683_thumb.pn

 

 

EDIT: Oh, you mean where to get them? Search for 2mm Shunt. Did I forget to include them?

 

http://www.mouser.com/ProductDetail/3M-Electronic-Solutions-Division/959102-0000-DA

http://www.ebay.com/itm/20-Micro-2mm-Jumpers-Shunts-SCSI-Laptop-Jumper-shunt-/350557475054

Thanks.  I ordered the bare boards, so you didn't forget to ship anything.

Share this post


Link to post
Share on other sites

Thanks.  I ordered the bare boards, so you didn't forget to ship anything.

 

Unless you're putting header pins it, you don't need jumpers. Just wire the points on the UAV to wherever you need them on the board. That's how you do 7800 or 4-switch 2600 installation, or I guess for the 800 given the location of the 4050. 

Share this post


Link to post
Share on other sites

Cross referencing THIS thread, I managed to hose color on my 800xl but I am confident it is temporary...

 

Will this device or the SOPHIA bypass whatever I did so I can get COLOR and great video after 30+ years? :)

 

With this board (and I suppose Sophia)- I read that with these you don't HAVE to mod anything on your board, but are there still some modding that makes these upgrades even better or is such butchering moot and redundant?

Share this post


Link to post
Share on other sites

Cross referencing THIS thread, I managed to hose color on my 800xl but I am confident it is temporary...

 

Will this device or the SOPHIA bypass whatever I did so I can get COLOR and great video after 30+ years? :)

 

With this board (and I suppose Sophia)- I read that with these you don't HAVE to mod anything on your board, but are there still some modding that makes these upgrades even better or is such butchering moot and redundant?

UAV picks up the signals early as they leave the GTIA, so it will work even when other parts of the circuit don't. As long as 1. The GTIA is functioning, 2. The proper pull-up resistors are still in place, and 3. There's nothing shorting/pulling the signals down.

Share this post


Link to post
Share on other sites

Ok Bryan, please PM me so I may see ordering options for an 800XL with a soon to be added Rev C Basic rom and currently a PAL Antic on a NTSC (with optional NTSC Antic). The Sophia RGB mod sounds awesome but my MIST computer already supports RGB and I haven't got ANYTHING RGB related working yet after TONS of cables, gadgets, adapters, etc.

Share this post


Link to post
Share on other sites

UAV picks up the signals early as they leave the GTIA, so it will work even when other parts of the circuit don't. As long as 1. The GTIA is functioning, 2. The proper pull-up resistors are still in place, and 3. There's nothing shorting/pulling the signals down.

 

Also, I removed C54 and C56 as mentioned in my cross referenced thread.  Are those some of the pull up resisters in your item 2 that would make your board not work until I fixed that?

Share this post


Link to post
Share on other sites

SOL Getting any of these finished, soon.


What is there to be finished? Are you building UAV boards from Bryan’s un-assembled kits? Or what?

Share this post


Link to post
Share on other sites

A 130XE install (under the shield)

 

This is one way to install the UAV under the shield of a 65XE/130XE which has very low clearance. This is basically a Kit with just the socket pins installed. Wire jumpers are soldered in in place of the 2mm header. I cut the ground pad, trimmed about 1mm off the socket pins, and installed a ground wire just because some of the ground routing is pretty bad on the XE's. This one has that purple jumper wire from the factory which is probably the acknowledgement that their original grounding sucked, but I ran my own ground anyway.

 

[url=http://atariage.com/forums/topic/246613-new-video-upgrade-coming-soon/?p=3467649]This post[/url] has the connection points. I picked off color at the back end of the leftmost 1K resistor in front of the 4050 socket, but it's the same as taking it off GTIA directly.

Share this post


Link to post
Share on other sites

2600 6-Switch

 

Another surprise! First time testing in a 6-SW VCS. You cannot use the power as it comes from the 4050 socket. There's a strange drop-down circuit that prevents UAV from working. You must cut the split pad for 5V and run a power wire to the board as shown. I also show where to pick up the color signal, and pin 6 must be lifted from the TIA socket.

Share this post


Link to post
Share on other sites

Hi Bryan,

 

could you please combine your installation instructures, sorted by system including the needed jumper settings, one time and make a single PDF or similar?

 

I´m pretty sure not to be the only one who built-in your fine devices for other people in their computers and consoles, but finding the right and actual settings here in this long thread are sometimes hard ;)

 

Thanks, Jurgen

Share this post


Link to post
Share on other sites

Hi Bryan,
 
could you please combine your installation instructures, sorted by system including the needed jumper settings, one time and make a single PDF or similar?
 
I´m pretty sure not to be the only one who built-in your fine devices for other people in their computers and consoles, but finding the right and actual settings here in this long thread are sometimes hard ;)
 
Thanks, Jurgen


The first couple posts in this thread generally have links sorted by system.

Share this post


Link to post
Share on other sites
Perhaps Bryan can setup one of those free websites (Wix, Weebly, ect) so that there is a central indexed area to find specifications and installation photos.

- Michael

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...