Current best S-video /picture improvement mod for 800XL?

[kogden]

Hey! Do let us know -- I've got a couple of 600XL's that I'm very unhappy with.

 

-Larry

 

Will do. Having nice clean S-video on this machine would make me a happy man. This one has all the fun stuff.... 512K Mega-Hz RAM extended RAM upgrade (switchable), MyIDE, internal USB SIO2PC, etc. It's an early machine so it has the nice solid keyboard (though non-stepped).

 

I think I would stop short of putting one of these in my 130XE though. On a 600XL it doesn't bug me because it didn't already have a monitor port. If I were going to do it on an 800XL or an XE I'd probably wire the board to a 5-pin DIN jack and desolder the existing jack onboard just to keep everything looking clean with no non-functional holes in the back of the machine except RF. I avoid external butchery if I can.

[BillC]

Hey! Do let us know -- I've got a couple of 600XL's that I'm very unhappy with.

 

-Larry

 

Will do. Having nice clean S-video on this machine would make me a happy man. This one has all the fun stuff.... 512K Mega-Hz RAM extended RAM upgrade (switchable), MyIDE, internal USB SIO2PC, etc. It's an early machine so it has the nice solid keyboard (though non-stepped).

 

I think I would stop short of putting one of these in my 130XE though. On a 600XL it doesn't bug me because it didn't already have a monitor port. If I were going to do it on an 800XL or an XE I'd probably wire the board to a 5-pin DIN jack and desolder the existing jack onboard just to keep everything looking clean with no non-functional holes in the back of the machine except RF. I avoid external butchery if I can.

I don't believe this board has provision for a port mounted on the board itself, I'm fairly certain that there are just points for connecting wiring to the external port(s) of your choice.

[kogden]

Hey! Do let us know -- I've got a couple of 600XL's that I'm very unhappy with.

 

-Larry

 

Will do. Having nice clean S-video on this machine would make me a happy man. This one has all the fun stuff.... 512K Mega-Hz RAM extended RAM upgrade (switchable), MyIDE, internal USB SIO2PC, etc. It's an early machine so it has the nice solid keyboard (though non-stepped).

 

I think I would stop short of putting one of these in my 130XE though. On a 600XL it doesn't bug me because it didn't already have a monitor port. If I were going to do it on an 800XL or an XE I'd probably wire the board to a 5-pin DIN jack and desolder the existing jack onboard just to keep everything looking clean with no non-functional holes in the back of the machine except RF. I avoid external butchery if I can.

I don't believe this board has provision for a port mounted on the board itself, I'm fairly certain that there are just points for connecting wiring to the external port(s) of your choice.

 

Exactly. What I was saying is I don't want to butcher the case to add AV jacks on an 800XL or XE and disable the monitor port. I would rather desolder the monitor DIN jack, flip it upside down (or use a new one) and solder pins to wires going to this board. By using this board you would disable the onboard monitor jack as you lift pins of the GTIA to go to video board. I don't like ports that don't actually work anymore visible on the back of the machine.

 

I actually already have the video board in hand. I've partially assembled it....missing a few components like the FMS6400 so it'll be a a little bit before I can give a real verdict. I'll try to take some pics with my iPhone of the output when I get it working.

[polbit]

All you have to do is to cut the Luma trace (and Chroma on 130xe) on the DIN monitor port, and solder the wires from the new board to the top of the port. No need to desolder the whole port.

 

Polbit

[BillC]

Hey! Do let us know -- I've got a couple of 600XL's that I'm very unhappy with.

 

-Larry

 

Will do. Having nice clean S-video on this machine would make me a happy man. This one has all the fun stuff.... 512K Mega-Hz RAM extended RAM upgrade (switchable), MyIDE, internal USB SIO2PC, etc. It's an early machine so it has the nice solid keyboard (though non-stepped).

 

I think I would stop short of putting one of these in my 130XE though. On a 600XL it doesn't bug me because it didn't already have a monitor port. If I were going to do it on an 800XL or an XE I'd probably wire the board to a 5-pin DIN jack and desolder the existing jack onboard just to keep everything looking clean with no non-functional holes in the back of the machine except RF. I avoid external butchery if I can.

I don't believe this board has provision for a port mounted on the board itself, I'm fairly certain that there are just points for connecting wiring to the external port(s) of your choice.

 

Exactly. What I was saying is I don't want to butcher the case to add AV jacks on an 800XL or XE and disable the monitor port. I would rather desolder the monitor DIN jack, flip it upside down (or use a new one) and solder pins to wires going to this board. By using this board you would disable the onboard monitor jack as you lift pins of the GTIA to go to video board. I don't like ports that don't actually work anymore visible on the back of the machine.

 

I actually already have the video board in hand. I've partially assembled it....missing a few components like the FMS6400 so it'll be a a little bit before I can give a real verdict. I'll try to take some pics with my iPhone of the output when I get it working.

All you have to do is to cut the Luma trace (and Chroma on 130xe) on the DIN monitor port, and solder the wires from the new board to the top of the port. No need to desolder the whole port.

 

Polbit

You don't need to remove the DIN5 or cut traces, just remove the components that connect the original signals to the jack, then solder the leads from the video board to the pads that lead to the DIN5 jack. The 800XL(and presumably 600XL as well) doesn't have a trace for the chroma signal so you would just connect your chroma signal lead directly to the correct pin of the DIN5 jack. The NTSC 600XL doesn't require removal of components to disconnect the original signals, but does require the addition of the jack and a hole in the case for it.

 

The signal paths can be back-traced, using schematics is helpful but you need to double check them as they sometimes contain errors.

[low_budget]

The Atari 5200 / 8bit s-video mod is discussed on this page with schematics.

 

http://www.atariage.com/forums/topic/193474-better-atari-5200-s-video-mod/page__st__25

 

I've been building and selling these on ebay since April.

This was originally an Atari 5200 s-video mod. Then I realized the Atari 8 bit computers have the same graphics chipset so it wouldn't be too difficult to make a version of the circuit that works on the computers as well. I looked up schematics of various Atari 8 bit computers and found the video modulation circuits varied quite a bit between different models. I just decided to build a complete video circuit so It would be simpler to write instructions for. It started out as a hybrid using portions of the Atari 800's circuit, the luma amp from the original 5200 s-video mod, and a FMS6400. It's been changed around a couple times and I think it's now a pretty good design. I also tested a circuit similar to Batari's Atari 2600 s-video mod, but that had vertical lines and several other odd issues so I won't be using that.

I've made 2 different versions of the PCB, with a third in the works.

v1.2 is for the Atari 5200 only

v2.0 is for the Atari 8 bit computers and the 5200. It is wired to 6 lifted pins of the GTIA.

v2.2 is in development and plugs into the GTIA socket (with pass through for the GTIA.)

 

If anyone has any questions about the mod feel free to PM me.

[Faicuai]

The Atari 5200 / 8bit s-video mod is discussed on this page with schematics.

 

http://www.atariage....od/page__st__25

 

(...)

 

If anyone has any questions about the mod feel free to PM me.

 

Just a quick question: the JungleHunt screen-shot you posted, is it from the 5200 or the XL/XE?

[Havok69]

I'd be interested in v2.2. (For a 1200XL) What kind of timeframe do you think until it's ready?

Edited June 9, 2012 by Havok69

[mimo]

Interested in v2.2 for a pal 400

[w1k]

2.0 please, for xe/xl

[+bf2k+]

I'd get a 2.2

[kogden]

Seems to filter audio some too......

 

No it doesn't, I'm retarded. He does instruct in the docs for the board to add a cap to filter audio though.

[low_budget]

I forgot to mention the GTIA pins don't need to be lifted, the kit can also be installed by removing the CD4050 and soldered to the correct points on the Atari circuit board. Also the 1k pull up resistors would need to be removed either from the Atari or the mod board. The color signal from GTIA pin 21 does not go to the CD4050, but instead to a transistor based amplifier. From pin 21 the signal passes through a 3.3k resistor and 10pf cap, so the first component would need to be removed for the wire going to the mod circuit. Later versions of my install instructions have this installation option covered. If the GTIA is not socketed or the owner prefers not to bend the GTIA pins this would be the best install option.

 

The v2.2 kit I hope to have ready for sale by late June.

It is untested in PAL machines, although it should work.

 

Thanks to Ransom for the suggestion to plug the board into the GTIA socket, which became v2.2

Thanks for poobah for suggesting I use machine pins for the board connection.

 

The screenshots I posted (in the Atari 5200 forum) are from an Atari 5200.

 

I've heard the 1200XL has a noisy ground, which may effect picture quality. I'm not sure if there's a way to fix that.

 

I'm working on a compatibility list for the version 2.2 kit.

If anyone knows what Atari computer models DO NOT have a socketed GTIA I would appreciate the info. I think it's just some of the later XE models.

The v2.2 PCB measures 2.4" wide by 2" high. The top of the board extends out 1-1/8" from the GTIA socket, so there cannot be any tall components in this area.

 

I uploaded my latest v2.0 installation instructions.

a 8bit svid kit v2 install.rtf

[kogden]

I'm working on a compatibility list for the version 2.2 kit.

If anyone knows what Atari computer models DO NOT have a socketed GTIA I would appreciate the info. I think it's just some of the later XE models.

 

Some late model 800XL's lack socketed chips for the most part. I have one such beast. Keyboard rattles like a box of marbles too when you type on it. Your 2.0 board would still probably be an easier install in such a machine. Pins on GTIA could be clipped or soldered directly to while in place. Not sure about the XE's, I think GTIA in mine MIGHT be socketed.....one of the big IC's in my 130XE is.

 

In 600XL's the onboard socket might need to be desoldered to have enough clearance with the keyboard when you put it all back together. Ran into this with a 512K RAM upgrade that sat under ANTIC. Had to solder RAM upgrade board directly to motherboard which also involved desocketing and directly soldering a couple more IC's to make room. Took a little work.

[Faicuai]

 

(...)

 

The screenshots I posted (in the Atari 5200 forum) are from an Atari 5200.

 

(...)

 

 

That's interesting...

 

I loaded up Jungle Hunt's on both Altirra (finely calibrated for NTSC-color rendering), in both XL and 5200 variants (and real XL machine also properly calibrated), and I am NOTreally getting the right-side tree-log colored in reddish-brown, like your sample shows...

 

...I do notice that selecting novice/advanced, etc., does change a bit color-scheme, but I never got the tree even-close to the color of your snapshot.

 

I find that strange, though. I simply can't pinpoint where the divergence comes from...

[kogden]

Will the v2.2 board w/ GTIA pass-through allow me to preserve the RF-out in a 400 as well as have S-Video, etc? I have a 48K 400 I'd like S-Video in but I don't want to hack up the existing system beyond a couple holes for jacks.

 

I want the 400 to be fairly stock though it has a couple minor mods.... the original RF cable started failing and the jack on the board seemed corroded so I soldered in a small length of RG-59 coax and put in a jack for an F connector on the back of the machine. No more crappy cable dangling out the back. I also put in an official 48K RAM upgrade. I plan on slapping in a new keyboard, retr0brighting it, and maybe S-Video.

[BillC]

Will the v2.2 board w/ GTIA pass-through allow me to preserve the RF-out in a 400 as well as have S-Video, etc? I have a 48K 400 I'd like S-Video in but I don't want to hack up the existing system beyond a couple holes for jacks.

 

I want the 400 to be fairly stock though it has a couple minor mods.... the original RF cable started failing and the jack on the board seemed corroded so I soldered in a small length of RG-59 coax and put in a jack for an F connector on the back of the machine. No more crappy cable dangling out the back. I also put in an official 48K RAM upgrade. I plan on slapping in a new keyboard, retr0brighting it, and maybe S-Video.

The GTIA in the 400/800 is on the CPU board in the back slot of the motherboard, I doubt there would be enough room under the shield to install the v2.2 board in the original GTIA socket. The attached schematic shows that the 6 signals are available at the 4050 and R196, or the test connector at the rear of the mainboard.

[kogden]

Will the v2.2 board w/ GTIA pass-through allow me to preserve the RF-out in a 400 as well as have S-Video, etc? I have a 48K 400 I'd like S-Video in but I don't want to hack up the existing system beyond a couple holes for jacks.

 

I want the 400 to be fairly stock though it has a couple minor mods.... the original RF cable started failing and the jack on the board seemed corroded so I soldered in a small length of RG-59 coax and put in a jack for an F connector on the back of the machine. No more crappy cable dangling out the back. I also put in an official 48K RAM upgrade. I plan on slapping in a new keyboard, retr0brighting it, and maybe S-Video.

The GTIA in the 400/800 is on the CPU board in the back slot of the motherboard, I doubt there would be enough room under the shield to install the v2.2 board in the original GTIA socket. The attached schematic shows that the 6 signals are available at the 4050 and R196, or the test connector at the rear of the mainboard.

 

Hmm... might be worth looking into....

 

I got the 2.0 board mostly put together and ready to slap in my 600XL -except- I forgot to order 6.2k and 9.1k resistors.....Radio Shack doesn't have them locally either so I guess it's time to wait on the Post Office again. I hate it when I do things like that....two $0.06 resistors LOL

 

Since I have to wait a bit anyway..... anyone know how long the wires to the GTIA can be without causing issues?

Edited June 13, 2012 by kogden

[low_budget]

Ok it seems installation of v2.2 in Atari 400 and 800 computers might not be possible. I was able to reduce the board's thickness by laying down the transistors and removing the on board GTIA socket and 22uf capacitor. The GTIA will need to be soldered to the mod board in the "thin" configuration.

Here are the installed dimensions:

PCB is 2-3/8" x 2"

The mod board sticks out 1-1/8" above the GTIA when installed (on the pin 21-40 side.)

There is 3/8" clearance below the mod board for existing components.

Installed height is 7/8" for the standard board with GTIA socket.

Installed height is 11/16" when assembled in the "thin" configuration.

 

I do not have an Atari 400 or 800, so if somebody could measure the CPU board to case clearance, that would be cool!

I'm also working on installation instructions for v2.2.

 

If anybody is interested in trying out the v2.2 circuit to see if it physically fits in their Atari computer, I could send them a kit for cheap, and if it doesn't work I will of course accept a return with refund. PM me if interested.

 

Until I have better knowledge of compatibility, I'm going to sell this as an Atari 5200 s-video kit.

 

Some more info about v2.2:

The luma, sync, and color pins do not pass through, so the original video circuit is completely bypassed (no RF out.)

There are jumpers on the bottom of the PCB to allow 5v and ground to tap off the Atari's GTIA socket.

This kit has the best picture quality I've been able to achieve; it's near perfect in my opinion.

COL now passes through the buffer

Has gold plated header pins for good connection

Each output can drive up to two video loads

I will probably offer the kit assembled in standard and thin configurations.

 

Regarding the v2.0 kit, the signal wires coming from the GTIA are digital, so there shouldn't be much interference. I used wires about 3" long in my install. As a general rule: the shorter the wires the better.

 

I'm not sure what is causing the color difference in Faicuai's system. I simply adjusted the color delay potentiometer until the colors looked right. There seems to be a narrow range where brown is displayed correctly. I use Joust to calibrate the color delay. The platforms are green or red if the adjustment is off.

Edited June 14, 2012 by low_budget

[sloopy]

What you may want to consider is, making the holes for the GTIA socket large enough so the larger part of a machine pin socket goes into them, and then the pins come out the bottom... put the components on the top side folded over, and the few resistors on the A8 CPU card on the back so there is clearance...

 

this would work well in the limited space of the CPU card, and the only thing to come out would be the wires for the output...

 

(if you need clarification, just ask ;')

sloopy.

[kogden]

I got the low_budget 2.0 S-Video board put together and installed. Results so far are quite favorable. No trace of vertical banding or clock lines. MUCH better results than I got with the KJMann board and better than I managed with entirely passive components.

 

If ordered as a kit instead of a bare board, it isn't much more difficult to install than the KJmann board either with much better results. There's still some minor color shadowing, etc but that's probably more the GTIA's fault.

 

 

Still have some cleanup work to do but it's working well. The RF modulator was still there when the first Svid jack was installed which is why I didn't just widen it and put the jack there. Will likely fill the hole with bondo and paint it.

 

Action shots running some software I'll post in a bit.... anything in particular anyone wants to see? I'll probably post a couple from a CRT and a couple from an LCD.

Edited June 19, 2012 by kogden

[kogden]

And yes, this machine was upgraded by butchering an IDE cable and a Cat5e stranded-core patch cable. This machine has had tons of horrid experiments performed on it so there's burnt flux and stuff I haven't bothered cleaning and even a lifted pad or two in spots. I don't do horrible expedient hacking like this on my other machines. This one is my plaything. Scarily enough, it even worked before installing this board but the video hack was awful looking though it produced OK video... not as nice as this though.

[low_budget]

I recently bought an Atari 800XL on ebay for $12 and was going to install the v2.2 kit in it. Unfortunately there isn't enough height clearance. So far I know v2.2 will not work in the 400, 800, and 800XL. I did install the v2.0 kit and it worked well though. I used the original monitor port by connecting the missing chroma wire and removing 2 inductors linking the port to the original video circuit. I couldn't find a monitor cable with TV style s-video connector and composite so I made one. I removed the RF modulator so the board would fit easily. Otherwise it looks like a stock 800XL.

 

I'm down to four v2.0 s-video PCBs left. I may have another run made if there's enough demand, but I'll take my time before I do.

[kogden]

I recently bought an Atari 800XL on ebay for $12 and was going to install the v2.2 kit in it. Unfortunately there isn't enough height clearance. So far I know v2.2 will not work in the 400, 800, and 800XL.

 

I had similar trouble with a RAM upgrade that sits under ANTIC. I had to remove the socket on motherboard and solder upgrade PCB to motherboard. Gave me the clearance I needed but made the RAM upgrade PERMANENT. Had to desocket 2 smaller ICs too.

 

If you get rid of the existing GTIA socket is the board still too tall?

 

I did install the v2.0 kit and it worked well though. I used the original monitor port by connecting the missing chroma wire and removing 2 inductors linking the port to the original video circuit. I couldn't find a monitor cable with TV style s-video connector and composite so I made one. I removed the RF modulator so the board would fit easily. Otherwise it looks like a stock 800XL

 

Cool! I got mine going but I tore up something fixing something else so I haven't posted screenshots yet. I need to replace the plain wire with shielded wire for jacks too. Noisy on my LCD but good on CRT.

 

I'm down to four v2.0 s-video PCBs left. I may have another run made if there's enough demand, but I'll take my time before I do.

 

Complete or plain PCB's? I'm interested in another unpopulated PCB.. Still have an extra FMS6400 and a 4050.

[BillC]

I recently bought an Atari 800XL on ebay for $12 and was going to install the v2.2 kit in it. Unfortunately there isn't enough height clearance. So far I know v2.2 will not work in the 400, 800, and 800XL. I did install the v2.0 kit and it worked well though. I used the original monitor port by connecting the missing chroma wire and removing 2 inductors linking the port to the original video circuit. I couldn't find a monitor cable with TV style s-video connector and composite so I made one. I removed the RF modulator so the board would fit easily. Otherwise it looks like a stock 800XL.

 

I'm down to four v2.0 s-video PCBs left. I may have another run made if there's enough demand, but I'll take my time before I do.

8-bit Classics sells DIN5 A/V cables for the Atari 8-bits.

$5 for composite/audio

$10 for s-video/composite/audio

 

http://www.8bitclass...l-products.html