Hi guys,
Apologies for not posting here that often lately.
Struggling to find free time at the moment.
Anyway, I scored an affordable RGB to S-video converter and was curious to see how it performed on my Sony TV.
Surprisingly, the quality was much better than expected :-)
(http://img294.imageshack.us/img294/3911/80columnsvideo1vd8.th.jpg) (http://img294.imageshack.us/my.php?image=80columnsvideo1vd8.jpg)
Time to get all 16 colours working on it.
Cheers
Fotios
Nice!!! Need, more info..
You have been a treasure to the C= community :-)
I think of him more as a superhero. You know, with FB superimposed on a lightning bolt on his chest. :)
Jokes aside, this is of more interest to me than an RBG to VGA adaptor because all the displays in my house have S-video inputs and the quality is quite good. It's also worth noting that the 128 can display 80 columns nicely through an S-video connection although it's only monochrome.
If you're planning on making and selling these then I can't wait! If not, details please! Golan is right; I have my Commie connnected to a 36-inch (1m) TV and it looks sharp in both 40 and 80 column, but monochrome is so boring (and impossible to use with some apps).
No need to thank me. Thank the guys in Taiwan who make this stuff :-)
I'm using the following converter
http://www.weiya.com.tw/products_1.asp?le=english&fid=114 (http://www.weiya.com.tw/products_1.asp?le=english&fid=114)
Seems to work fine on my TV with an Amiga as well.
(http://img254.imageshack.us/img254/8186/amigasvideo3zi4.th.jpg) (http://img254.imageshack.us/my.php?image=amigasvideo3zi4.jpg)
My TV is a 5+ year old Sony that has a mode called Game Mode. When active, it's like a flicker fixer that gets rid of the interlaced effect in 640x512 mode. After all this time I finally figured out what this mode was for... the description in the Sony user guide was crap.
(http://img257.imageshack.us/img257/7263/amigasvideo2yu4.th.jpg) (http://img257.imageshack.us/my.php?image=amigasvideo2yu4.jpg)
The image is better than the photos shown due to my crap photography skills.
I don't have any plans to resell these... However, I'll try to source some from the manufacturer at wholesale prices.
I wonder how it will perform on a S-Video to VGA converter... there's so many around. Any recommendations?
Cheers
Fotios
Is the 16-color conversion the same as for the VGA converter? 3 resistors?
Not sure. I need to spend some time reverse engineering it but I'm keeping my fingers crossed that a few diodes and resistors will once again do the trick.
Thanks for the link. It's a shame it needs 12V instead of 5V, but if it doesn't draw too much current, it should be possible to convert the 9VAC out of the user port (conviently located by the RGBI port).
The large view of the board marks the output as composite, but you said you were using S-Video. So did you just tap the Luma / Croma lines before the composite stage?
I'm thinking of using it with a 128D that has +12V.
The S-video socket is between the power and composite sockets.
How much regulated 12V current comes off the 7812 (U59) regulator in a flat C128? It's pumping 12V for the 6581 SID, but I don't know the circuit's capacity. Looks to me like the caps and diodes should handle some extra load, and the 7812 should be okay with it. The output's got a 10 uf cap on it, so I can't believe it would affect the SID much. There's no outside connection, but you should be able to clip onto it with a pigtail pretty easily.
Well, the video converter circuit spec sheet states that a 125mA +12V supply will do the job.
Quote from: AirshipHow much regulated 12V current comes off the 7812 (U59) regulator in a flat C128?
I don't know because the 7812 is a very common component made by several companies in a wide range of current ratings. It wouldn't suprise me if Commodore used several types in the different production runs. Anyway, a quick google shows ratings from 500mA to over 2000mA, so I think whatever 7812 was used should be OK.
But, the circuit is fed by the 9V AC. The 9V output on the user port is spec'd at 100mA. So this neat device may draw too much current... It really depends on how much 9V current the power brick supplies. The markings on my power supply specifies ~1000mA. Since the C128 PRG states the worst-case consumption is 5.2W of 9V = 577mA, over 400mA should still be available from the power brick, so it may work after all!
Now I'm even more curious about this device. Is there a way I can buy 1 (and not 50+) ?
Quote from: hydrophilic on April 26, 2008, 08:59 AM
Now I'm even more curious about this device. Is there a way I can buy 1 (and not 50+) ?
This eBayer seems to list them from time to time.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=310046061559 (http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&rd=1&item=310046061559)
Thanks Mangelore!!
(duh, eBay... hydro slaps forehead with palm)
And very reasonably priced. Excuse me while I do some accounting...
Edit
I just noticed the item is located in Canada. It should get here by Christmas right?
/Edit
Let's not start THAT discussion again! Last time we started in on Canada Post we lost a half dozen good members! :(
I am working on something similar to this device based on the AD72X series ( Probably AD724...should get my sample soon, just waiting to get an oscilloscope )
http://www.analog.com/en/prod/0,,765_798_AD724,00.html (http://www.analog.com/en/prod/0,,765_798_AD724,00.html)
Cool!
Just so you know, the device I'm using is based on the BH7236AF
http://www.datasheetcatalog.com/datasheets_pdf/B/H/7/2/BH7236AF.shtml (http://www.datasheetcatalog.com/datasheets_pdf/B/H/7/2/BH7236AF.shtml)
I just got my RGB to S-Video/Composite converter and it works very nice... thanks again Mangelore!! I ordered from the guy Mangelore mentioned. It was $25 + $13 shipping. Shipping took about a week but I'm not gonna blame the seller, all things considered.
The converter also came with: Composite, S-Video, and DC Jack cables. Note it does not come with 12V DC adapter. Also included was a specification sheet. It says (amongst other things) that it operates on 8 to 15 V DC.
To test it, I went to RadioShack and bought a 9-pin male D-sub connector, matching housing, and a pack of 9V battery clips. About $8 with tax. The one thing I really needed I could not find: a post connector :mad: The device has two post connectors. One is 'large' with all input signals except V-Sync. The small one has all input signals. Since they didn't have any post connectors :mad:, I used some in-line crimp connectors. Needless to say the video-in wiring looks really bad...
After hooking up the device I powered it on and ... nothing! After double checking my wiring and testing that Ground, RGB, H-Sync and V-Sync signals were reaching the device, I thought maybe 9V wasn't enough (or maybe the battery I was testing with was too old). So I cracked open a 1571 and borrowed its power supply. Connected 12V, powered it up and ... nothing!
I was getting worried at that point. I verified the power connection. Yep, 13.3V on the DC plug and the Positive was connected to the pin labeled +12V on the circuit board.
Then I remember the photo the seller had posted about how to connect the DC plug's wires... they were backwards from what I was using. I used a multi-meter and discovered the connector on the board labeled +12V was actually common to the ground. And the pin labeld CON only went to a diode which was reverse-biased with the polarity I was trying to use.
So I switched the polarity that the 1571 supply was feeding the device and... success! A color 80-column display :) :)
Next I set aside the 1571 and re-attached the 9V battery (with the right polarity). I turned it on and... success :)
At this point I was using the Composite output because the front of my TV only has composite video in. I was worried because the image was very blurry. (Previously I was using composite with the 128's monochrome output and it gave a very sharp picture).
So I crossed my fingers, climbed behind the TV to connect the S-Video cable, turned it on and... success: A colorful and sharp 80-Column display :) :) :)
Obviously I'm biased, but the Color S-Video looks as sharp as the monochrome composite. And it looks better, not just because of color, but because of brightness. With monochrome, the output was too bright with the standard TV settings (I would change from bright cyan to a dark color like blue to get a slightly dimmer but still 'white' text display). But with the Color S-Video, the brightness is perfect. The device comes with 3 pots to adjust R, B, and G signals but I didn't need to touch them.
If you have C128 and no 80-column monitor, I recommend this if:
1) You have TV with S-Video input
or
2) You have a good 40-column monitor -- meaning one with seperate chroma and luma inputs like the 1702 because seperate luma/chroma is exactly what S-Video is... Commodore was ahead of the home entertainment industry :)
and
3) You have a nack for simple electronic projects
Important point to remember: the DC Plug should be wired with a positive tip and a negative barrell (ignore the +12V marking on the board).
Next I'm gonna dig around for some diodes and resistors and see what I can do about intensity. I'll also use some diodes to build a bridge rectifier and put a big capacitor on it, then test it with 9VAC. I should probably get a case to hide my ugly wiring :)
What about the CGA colour issue?
The device does a straight RGB conversion so there is no color issue with a television. There shouldn't be any problem with a Commodore monitor (like 1702). The only problem, I guess, would be if you tried to use an IBM/CGA monitor -- but I don't have one so I can't be sure...
D'oh. I didn't occur to me that the problems associated with a 128 to VGA adaptor wouldn't be present with this device. Sounds like I'll have to get one. Anything to be rid of the need for monitors.
Quote from: Mangelore on April 17, 2008, 05:41 PM
No need to thank me. Thank the guys in Taiwan who make this stuff :-)
I'm using the following converter
http://www.weiya.com.tw/products_1.asp?le=english&fid=114 (http://www.weiya.com.tw/products_1.asp?le=english&fid=114)
Seems to work fine on my TV with an Amiga as well.
(http://img254.imageshack.us/img254/8186/amigasvideo3zi4.th.jpg) (http://img254.imageshack.us/my.php?image=amigasvideo3zi4.jpg)
My TV is a 5+ year old Sony that has a mode called Game Mode. When active, it's like a flicker fixer that gets rid of the interlaced effect in 640x512 mode. After all this time I finally figured out what this mode was for... the description in the Sony user guide was crap.
(http://img257.imageshack.us/img257/7263/amigasvideo2yu4.th.jpg) (http://img257.imageshack.us/my.php?image=amigasvideo2yu4.jpg)
wow..glad i checked in to this site....youre telling me that this thing is actually good for AGA games as well i.e no colour loss????
Does anyone know of another supplier for this converter? I checked the ebay site listed, but he's not selling right now. I have contacted the manufacturer, but i have not gotten a response as of yet.
I had a thomson monitor , but it smoked - quite literally!!
thanks :)
got128
Bumping this thread...
Mangelore, Hydrophilic, did you ever get Intensity wired up? Did it work?
Has anyone found another (preferably US) supplier?
No I haven't got the intensity or the power-via-C128 wired up. My f*** car has been taking away from my precious Commodore time :( Its on my todo list so I'll post eventually.
As long as I'm posting I just want to make some comments about this tiny device.
It does RGB conversion so you only get 8 colors and not all 16. For all 16 colors you need the intensity circuit we're talking about. An ASCII schematic for you:
+----/\/\/\/---->|---- R
|
I --+----/\/\/\/---->|---- G
|
+----/\/\/\/---->|---- B
where the resistors are around 680 ohms. The normal R,G,B lines from the C128 would also connect to R,G,B above. Here's a picture (http://img442.imageshack.us/my.php?image=bottom2tb8.jpg) of one soldered directly to a converter board. Not how I'd do it... I don't trust my soldering skills on this device -- lots of surface mount components!
Also let me say this device has two post connectors. A large, 5-post connector which supports composite-sync RGB input, and a small, 6-post connector which supports seperate(H and V)-sync RGB input. The C128's VDC produces seperate H,V outputs so plan on using the small connector. You could easily create a composite sync by connecting the H and V with a capacitor but I don't what value to use (in this case use the large connector).
Also the composite-sync on the large connector is wired to H sync on the small connector. This might be important if for some reason you wanted to use both connectors. Using both connectors may sound unlikely, but is actually what I did because I didn't have a proper connector; I used wire crimps which fit nicely on the big posts but I still needed the V sync from the small connector.
I just tested the cassette motor output on my flat C128 and I am getting a reading of only 6.4V. The RGB converter I'm using works fine with 9V DC but not at all with 6.4...
I just double-checked the schematics and the cassette motor output is tied to +9V DC through a 2SD880 transistor. I was thinking it would drop less than a volt but it's more like a 2.6 voltage drop...
Is a 6.4V output normal for the cassette motor or is my commie defective?
Anyway, I guess I'll have to go with plan 2: the user port + voltage rectifier. Does anyone have a connector for that they want to sell me or can recommend a source?
As long as I'm wiring up the user port, I might as well make a serial interface to connect with my PC. The PC's serial port uses TTL levels right?
The Ebay site is up again. The Item Number is 310107450899.
Quote from: megabit on December 14, 2008, 10:18 AMThe Item Number is 310107450899.
Thanks! I just ordered one.
Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore/Amiga Network
http://www.sccaners.org/
Make sure you ask him to include the right connector cable.
Quote from: me on December 14, 2008, 01:10 PMI just ordered one.
Still waiting on my order from Canada. The seller sent a letter, saying that it should arrive soon (I estimate around New Year's).
Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore/Amiga Network
http://www.sccaners.org/
Patience pays off - finally. Thanks for watching Ebay. Honestly, i had given up and found a nice 1902A.
I think $25 plus shipping is a good deal for the adapter AND =D 25-year-old hardware does have a tendency to fail.
Thanks again - i'm getting one
got128
Quote from: got128 on December 29, 2008, 04:04 AMPatience pays off - finally.
I, too, can be very patient. If I miss something the first time around, I always say that there will be another time. :)
Happy New Year!
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore/Amiga Network
http://www.sccaners.org/
Quote from: me on December 28, 2008, 06:42 PM...saying that it should arrive soon (I estimate around New Year's).
When I got back home last night, the package was waiting in the mail! I eagerly opened the yellow packing bag, and inside, I found a plastic ziplock bag with all the goodies -- a form letter from Yao (the owner of the business?), a RGB to Video Converter Model #S-1 sheet of specifications and rough usage rules (but no assembly instructions), a S-video cord, a cable with a S-1 board connector on one end and tinned leads on the other end, another cable with a different S-1 board connector on one end with tinned leads on the other, a composite video cable, a cable with a coax power plug on one end and tinned leads on the other end, and wrapped in a bubble wrap -- the S-1 board.
It's interesting that the board has 3 adjustable pots, two different connectors for those RGB input cables, and a slideswitch for NTSC/PAL. Printed on the board and listed in the form letter is Yao's website, http://www.arcademvs.com
Assembly definitely required,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
The Other Group of Amigoids
http://www.calweb.com/~rabel1/
Southern California Commodore/Amiga Network
http://www.sccaners.org/
That is a really cool product :)
I'd love to see some pictures of your screen in order to see the quality of the output of this device. But it doesn't have an input for the intensitysignal, does it? (Hard to tell from their picture). If not, you'll only get 8 colors. But still, it's 80-column on a TV-set in color :)
They also have a CGA to VGA adapter, has anyone tried that?
Just got an email from the seller saying that he shipped it.
Once i get mine, I'd like to take a look at it and see if Mangalore's mod for RGBI can be performed on it.
More news later. . . :) :) :) :)
I also had something like that in mind :) Mangelore's mod is a great one, let's hope it can be applied to this device as well.
Sorry to bump an old thread, but nobody ever posted any pix and I've got some.
Here is the S-Video output:
(http://sites.google.com/site/h2obsession/CBM/C128/images/rgbi-both.JPG)
And here it the Composite output:
(http://sites.google.com/site/h2obsession/CBM/C128/images/composite.JPG)
Here is the schematic I used:
(http://sites.google.com/site/h2obsession/CBM/C128/images/pull-both.gif)
I tried using only 3 resistors and diodes, but the results weren't as good as I hoped so I used the slightly more complex design above. For some more pix and schematics on this you can visit my RGBI to S-Video page (http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video).
To recap, the RGB converter was about $40 bucks and $10 or so for parts gives you 16-color S-Video. If you want VGA, could add on one of those S-Video to VGA boards that run around $49. That would give you RGBI to VGA for around $99 (but there's a VGA thread already).
The S-Video looks awesome. Think it would work with interlace (640x400)?
I sure hope interlace works. I had a problem with interlace using plain monochrome because I didn't really understand the VDC documentation. As soon as I finish the case and get it all assembled, I plan on testing out all the video modes. There is a request in the software section for a program to do that (test all video modes), so I'll post the program I write and keep you informed. Don't hold your breath however, I've been working on the hardware for almost a year now. It's such a simple circuit too... how embarrasing!
That looks to be a lot cheaper than the JROK adaptors everyone else has been using.
I wonder how hard it would be to rig one of these up internally. Maybe using a switcher (triggered by the 80/40 column key) to switch between the 40 and 80 column output?
Quote from: Hydrophilic on October 02, 2009, 04:31 PM
(http://sites.google.com/site/h2obsession/CBM/C128/images/pull-both.gif)
If you don't mind I'll steal this :-) Just saved me some faffing around as it's nicer than the one I came up with.
I got hold of a cheap RGB to component converter, all it requires is RGB + composite for inputs, your schematic gets me the nice RGB and the C128 outputs the composite over the RGBI connector anyway :-)
Off to Jarcar I go to get bits, be interesting to see if the LCD will accept the feed.
Thanks
Mark
Quote from: Mark SmithIf you don't mind I'll steal this
I'm honored. Let us know how it works for you!
When I was testing different values, I found that ratio of resistor values was more important than absolute resistance. Something like 500 ohm for the I-resistor and 410 ohm for the R/G/B-resistors would produce about the same result. (I can try to explain that again if anybody is confused)
I used those values pictured (1k and 3*820) -- which are kinda big compared to some other schemas I've seen -- because the output of the video driver in the C128 uses totem pole (not open collector) output and are not very powerful. My databook said something like 20 to 30 mAmps per line, and the I-line has to drive three lines. I also used those values cause I had them laying around so I didn't need to go shopping.
Quote from: Mark Smith
...be interesting to see if the LCD will accept the feed
Good luck. The LCD hooked to my PC is crazy! If I switch my PC resolution to 320x200, the monitor shows the picture correctly, but a big overlay message appears in the middle of the screen "Signal Out of Range" or some other non-sense. Arggggh!
Quote from: saehnThink it would work with interlace (640x400)?
Yes, it does work ;D
I was planning to snap some photos this past weekend but then I had two more projects given to me... maybe this weekend...
I was wondering if Mark Smith ever got his RGBI converter built and how it works?
I also wanted to report that I've tested interlace mode some more and it does work. This weekend I tested ZED and both 45-line and 51-line modes work. However I am not able to adjust the vertical position on my television, so the top line gets cut off (and the bottom line too in 51-line mode). Because of this, I didn't take any snapshots for you. When I get a chance, I'll change the vertical position in the ZED program and get a screenshot of the 45-line mode.
Here is one screens shot of interlace mode I did from BASIC. Because BASIC/KERNAL can't handle more than 25 lines, the bottom 25 lines have garbage. Also the top/side is out of focus due to the large, curved nature of my TV (or my lack of photography skills).
(http://sites.google.com/site/h2obsession/CBM/C128/images/DRAM3_sd.jpg)
Quote from: RobertBIt's interesting that the board has 3 adjustable pots, two different connectors for those RGB input cables, and a slideswitch for NTSC/PAL. Printed on the board and listed in the form letter is Yao's website, http://www.arcademvs.com/ (http://www.arcademvs.com)
Sounds like you've got the same board I do. If the color ever suddenly vanishes, check the NTSC/PAL switch. I spent a few hours checking my circuit because I had no color only to find that I had somehow switched it to the wrong standard.
And I
finally got to play my BattleBlox game (http://sites.google.com/site/h2obsession/CBM/C128/images/BatlBlox.zip) on a real C128. A lot of fun! Although not interlace, I got a screen shot for you anyway:
(http://sites.google.com/site/h2obsession/CBM/C128/images/BattleBlox.jpg)
Quote from: Hydrophilic on November 17, 2009, 01:58 PM
Sounds like you've got the same board I do. If the color ever suddenly vanishes, check the NTSC/PAL switch.
Thanks for the hint.
QuoteAnd I finally got to play my BattleBlox game (http://sites.google.com/site/h2obsession/CBM/C128/images/BatlBlox.zip) on a real C128.
What!!! A new 80-column game!!! It's been quite awhile since one of these appeared. What was the last one... Starship Battles? And that was back in 2006 or so.
Yes, more and more 80-column stuff!
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug (http://videocam.net.au/fcug)
The Other Group of Amigoids
http://www.calweb.com/~rabel1/ (http://www.calweb.com/~rabel1/)
Southern California Commodore & Amiga Network
http://www.sccaners.org (http://www.sccaners.org)
It's not a new game. If you look at the screen shot, my copyright is clearly 2007. Its from the 4k Demo Competition that Lance hosted back then. I was just going to post a link, but can't seem to find the page with all the entries. But I've been dying to a play it on a real C128 since I wrote it, and now I can die happy!
I've attached a photo of the case of my RGBI-to-S-Video connector. The RGB-to-S-Video is at the bottom. I didn't get any connectors with that board (except a power plug) and I couldn't find any that fit, so you can see the crimp connectors I used (the vertical tubes with wires sticking out).
The RGBI-to-RGB board is mounted vertically in the back of the case; this has wires going into the crimp connectors, plus two more going to the monochorme output. Monochrome is just for completeness because RGB converter produces a color Composite signal too.
The vertical board will also eventually have my 9VAC to DC converter. In the background you can see a bread board which has the voltage converter. I still get some small interference on the VIC screen when this is pluged up. I might break down and buy a 9VDC voltage regulator IC because right now it is a simple full-wave rectifier with 1500uF filter. Of course part of the problem is the fairly long unshielded power wires.
More photos and info on my RGBI to S-Video page (http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video).
Quote from: Hydrophilic on November 17, 2009, 04:35 PM
It's not a new game. If you look at the screen shot, my copyright is clearly 2007.
Yup, I saw that. But it's new to me. :)
QuoteIts from the 4k Demo Competition that Lance hosted back then.
Ah, I must not have been paying attention then. :)
Yes, more and more 80-column stuff!
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug (http://videocam.net.au/fcug)
The Other Group of Amigoids
http://www.calweb.com/~rabel1/ (http://www.calweb.com/~rabel1/)
Southern California Commodore & Amiga Network
http://www.sccaners.org (http://www.sccaners.org)
I've got another screen shot that shows VDC real interlace mode using a modified version of ZED. This is ZED mode 4, for lack of a better term. Once you start ZED, press the key combination [C=] + [4] to activate. It is an interlaced 80 x 45 char display.
I had to modify ZED to use correct NTSC specs (525 rasters) because the official distribution uses 519 rasters which my TV does not like. More info, including a bad screen shot with default (wrong) NTSC parameters, are on my RGBI to S-Video page. (http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video)
BTW, who is the author of ZED? I would like to get his/her permission to distribute the modified version (http://sites.google.com/site/h2obsession/CBM/C128/images/zed78.zip). (if not, I can provide instructions on how one can modify it, only 2 bytes need changing)
Google is your friend...
Craig Bruce
http://www.csbruce.com/~csbruce/cbm/zed/ (http://www.csbruce.com/~csbruce/cbm/zed/)
I don't know if the email address there is still valid.
BTW, I found a d.i.y. RGB-to-NTSC (or PAL) converter intended for the Atari ST. I don't know how good 80-column composite color would look on a television or monitor. Frankly, it looks too simple to me, but it might be worth trying.
http://www.preromanbritain.com/gwem/martbean/ataridiy/conv.htm (http://www.preromanbritain.com/gwem/martbean/ataridiy/conv.htm)
csbruce@cubewerx.com
Thanks for the info. I have asked the master for his blessing!
Quote from: richardc64 on November 29, 2009, 12:24 AM
...I found a d.i.y. RGB-to-NTSC (or PAL) converter intended for the Atari ST. I don't know how good 80-column composite color would look on a television or monitor. Frankly, it looks too simple to me, but it might be worth trying.
http://www.preromanbritain.com/gwem/martbean/ataridiy/conv.htm (http://www.preromanbritain.com/gwem/martbean/ataridiy/conv.htm)
Your definition of simple is different from mine. Thanks. I've added a link to it on my website (http://sites.google.com/site/h2obsession/CBM/C128/rgb-conversion)for anyone else who is as brave as you.
I believe this is an RGBA converter, not an RGBI converter. Right? So it wouldn't work with the C128.
Good point. As shown, I don't think the circuit would work. But with a few tweeks I think it would.
Although I know virtually nothing of the ST's I/O specs, the acrticle points out that its R,G,B outputs are 1.8 Vp-p with a 1.2 Vdc bias. It also says the caps and resistors in the schematic are used to remove the dc bias and provide 1.0 Vp-p for the MC1377 converter.
So this should work with a C128 by changing the resistor values on the R,G,B lines. I'm thinking that about 0.2 mA goes through each 4K resistor to produce the 0.8 V drop (from 1.8 to 1.0). So maybe using 20k resistors will drop the TTL voltages of the C128 down to 1.0V for that chip?
Other than that, there is the issue of the syncs. If the VDC syncs are active high (I'm thinking this but not sure), the AND gate would need to be replaced by a NOR gate. This is a relatively minor change and can be changed in software too, via register 37 of 8568 equiped C128 D[CR]s (so I've read, I got a flat C128 with 8563 so I can't confirm).
Hmm, I wonder if inverters would be needed on the R,G,B lines? The VDC outputs are active high for R,G,B (I've tested).
I won't try building it, but I think it could work with a few tweaks like mentioned above. Of course it will produce only 8 colors without adding circuitry for Intensity. Also note that composite color video is not very pretty in the best case and the author says the color-filter circuit is not great.
The circuit might be made simpler because the author also states the chip can produce the color-burst itself without an external oscilator as shown.
Edit
I just noticed that the pre-fabricated RGB to S-Video board I bought (I think RobertB has the same one) is available on eBay for only $29.99 (http://stores.ebay.com/yplus). I am extremely happy with mine. Please note it only provides 8 of the 16 colors without additional circuitry. However the required circuit is much simpler than the one discussed above; review previous posts in this topic for more details.
Maybe this should go under eBay auctions? It ends in just a few hours and is buy-it-now, so probably not. Anyway, this guy seems to sell them often, so check back later if you missed it.
/Edit
Only $24.99 & $12 shpg. now. Poster says he has 'more than 10' to sell at that price.
This is great, I just ordered a board. My 128T is using the RGB to SVGA adapter, but it doesn't do interlace mode. I guess the trick will be finding a TV with "game mode" for flicker fixing?
The next step I am thinking is to convert from composite to SVGA suitable for use with a standard LCD monitor, but it must display good on LCD and interlace modes. Here are the 2 on my radar.
http://www.buy.com/retail/product.asp?sku=206778928&listingid=22031194
This one says it has the most recent de-interlace technology. And then there is this one.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120395398191&ssPageName=STRK:MEWAX:IT
Which is unclear how it will treat interlace, but has multiple inputs to switch between.
Anyone have thoughts on this? My 40 col ntsc to SVGA adapter leaves some to be desired. It looks o-k on crt monitors, but terrible on LCDs.
I have to dis-recommend the second unit on eBay because it does not support S-Video, only Composite input. Composite output results in a very distorted (blurry) picture due to the limited color bandwidth. If you look on my webpage (http://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video), you can find Composite and S-Video shots to compare. Unfortunately they're not side-by-side... sorry! The best S-Video shot is to the right of the last schematic, and the equivalent Composite screen shot is on the left below the schematic.
Anyway, it should be obvious from those photos that the Composite is much more blurry. Imagine taking a blurry picture and turning into VGA and then possibly doing de-interlace and I bet it would look terrible on any type of display...
The first unit on Buy.com doesn't offer the multiple inputs, but it says it has S-Video input (however no S-Video connector is visible in photos).
As for de-interlace, I can't say because I'm using a CRT television. VGA monitors (at least my old CRT unit) can support interlace. So if using an LCD VGA monitor, it may support de-interlace already... I guess you won't know until you try...
I'm also assuming you have an existing LCD VGA monitor you want to use. If you are buying a new one, I would recommend a monitor that has S-Video input already! These almost always support some type of de-interlace / gaming mode function... and if it doesn't just return it!
Have fun!
@Hydrophilic
I finally got around to testing this on my bedroom TV. This TV sucks bad, but it works!
http://i41.tinypic.com/21411ea.jpg
My USB TV tuner for the peecee? Not so good, no picture in interlace and even distorted in standard 80 column. Oh well. I am curious how a better TV would look.
Quote from: redrumloa on March 14, 2010, 11:14 AM
I finally got around to testing this on my bedroom TV. This TV sucks bad, but it works!
Actually, compensating mentally for the fact that photos of TVs usually look worse than the actual real-life screen, I think it looks pretty good! I'm almost tempted...
Out of curiosity, this weekend I hooked my 128 with this adapter to my 50" Toshiba DLP TV. The results were very poor in standard 80 column, with parts of the screen being cut off. In interlace mode the picture was worthless.
It is doubtful anyone would want to use a 50" DLP TV with their 128, but I figured I'd put it out there.
On a related note, I am on the market for a 17-19 inch LCD for future every day use with my 128T. The LCD TV I used for testing in the picture a few posts ago in this thread works fine, but the TV itself has a poor picture. I know it is not the adapter, it is the TV. This model TV is crap. Anyone using a TV in this size range with a rock solid picture? If so, please post the make and model number.
does anyone know if the "Arcade RGBS CGA/EGA/YUV TO 2 VGA CONVERTER(NEW)" works? (Its the guys site who sells the RGB converter) http://www.arcademvs.com/ARCADE_ACESSERIOR.htm
would that also do it?
I'm electronically inept so, while I understand "add resistors" I don't get the "how" to add part :/
@BloodyCactus
It looks very similar to another board that others here (magelore iirc) discovered worked with the small resistor and diode mod. I currently have one in my 128 Tower. It does a pretty good job with CRT monitors, but leaves a little to be desired with LCD monitors. It does not handle interlace modes, but honestly there is almost zero software that supports interlace mode.
In a week, give or take, I plan on gutting both my VGA adapters out of my 128T and selling them. The RGB->SVGA adapter already has the modification for 16 colors and with the composite -> adapter, I have it set up to switch between 40/80 column on the fly. If you are interested, we can speak when I get back in town ~Friday. It would need a few small mods to be used externally, and you may want to put it in a project case to be clean. If not interested, no problem just throwing it out there thinking out loud. It should be a pretty quick sale on eBay.
Hi All,
Just a quick thanks to everyone here and Hydrophilic for the cool intensity hack!
I just finished this hack over the weekend and it works great. I can't wait to get rid of my 1902A monitor now...
Anybody know of any cool 80 column games other than the ones by Infocom?
PS: I didn't have a 9V or 12V adapter handy so I am using a 15V one. The specs say that 15V is OK so I hope I don't burn the board...
Regards,
ed...
No games to recommend here, but if you don't have BASIC 8 yet, get a copy. You should also get BigDumbDinosaur's 80-column Manager. It's pretty awesome.
Quote from: crazyegg on May 04, 2010, 02:30 AMAnybody know of any cool 80 column games other than the ones by Infocom?
Not commercial but homebrew 80-column games can be found at
http://cbmfiles.com/genie/C128GamesListing.php
Truly,
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug
July 24-25 Commodore Vegas Expo 2010 - http://www.commodore.ca/forum
and click on ComVEX
@redrumloa, I have to agree with airship, that the image doesn't look bad in your photo. It looks like you are using S-Video connector in the photo. Interlace looks good on my 36 inch CRT TV (there is some flicker), but the highest resolutions of ZED also get cutoff at the top. Also note that ZED does not use correct NTSC settings, so that might be a problem. What kind of board did you use in your C128 tower? I've read that it has s-video for 80-columns with some modification. (By the way, your C128 tower if f*king awesome)
@BloodyCactus, I haven't tried the board you mentioned; it sounds like what redrumloa used?
@crazyegg, I'm glad the Intensity hack works for you; Rest In Peace 1902 (I wonder if you could sell it on eBay?); I hope 15V is safe too, please let us know if it burns up...
I tried a variation on my Pull-Both method which uses more common resistor values AND looks better than the original. I've attached schematic. It uses 3 resistors of 1.0k and 1 resistor of 1.2k. Note for a slight penalty in color "crispness" you can use all 1.0k Ohm resistors... you can't get more common than that!
Hi All,
Thanks for the 80 Col program recommendations. There are quite a few indeed...
Of note, for those of you also using SVIDEO on the 40 column output of the C128, you will need to plug that output to a different SVIDEO input of the TV or use a SVIDEO box changer. I tried originally using a cheap SVIDEO Y-adapter (for both 40 col and 80 col) and it was causing interference.
Also, its a shame that most of the new LCDs that are out don't even have any SVIDEO inputs! But those that do only sport one SVIDEO input...
PS: I am currently using the revised schematic of Hydrophilic and it is working great on my LCD. So far so good on the 15V AC adapter. I remember I was using an 18V AC adapter for the longest time on my Nintendo 8 bit machine (rated at 9V or so) with no ill effect!
Regards,
ed...
Quote from: Hydrophilic on May 06, 2010, 05:38 PM
@redrumloa, I have to agree with airship, that the image doesn't look bad in your photo. It looks like you are using S-Video connector in the photo. Interlace looks good on my 36 inch CRT TV (there is some flicker), but the highest resolutions of ZED also get cutoff at the top. Also note that ZED does not use correct NTSC settings, so that might be a problem. What kind of board did you use in your C128 tower? I've read that it has s-video for 80-columns with some modification. (By the way, your C128 tower if f*king awesome)
Thanks for the compliment. That image earlier in this thread was when I was testing out on a flat 128 with a Viewsonic LCD TV. The remark was about the TV itself, it is a poor TV. The adapter has since been installed in the 128T and I bought a new Broksonic LCD TV, which has a fantastic picture. The 128T does indeed use only S-Video output for both 40 & 80 column.