C128 80 clumn RGB to S-Video...

[hydrophilic]

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?

[megabit]

The Ebay site is up again. The Item Number is 310107450899.

[RobertB]

The 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/

[Golan Klinger]

Make sure you ask him to include the right connector cable.

[RobertB]

I 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/

[got128]

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

[RobertB]

Patience 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/

[RobertB]

...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/

[SmallCleverDinosaur]

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?

[got128]

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. . . 

[SmallCleverDinosaur]

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.

[Hydrophilic]

Sorry to bump an old thread, but nobody ever posted any pix and I've got some.

Here is the S-Video output:


And here it the Composite output:



Here is the schematic I used:





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.

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).

[saehn]

The S-Video looks awesome. Think it would work with interlace (640x400)?

[Hydrophilic]

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!

[papa_november]

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?

[Mark Smith]

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

[Hydrophilic]

If 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.

...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!

Think it would work with interlace (640x400)?

Yes, it does work 

I was planning to snap some photos this past weekend but then I had two more projects given to me... maybe this weekend...

[Hydrophilic]

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).

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/

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 on a real C128.  A lot of fun!  Although not interlace, I got a screen shot for you anyway:

[RobertB]

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.

And I finally got to play my BattleBlox game 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
               The Other Group of Amigoids
               http://www.calweb.com/~rabel1/
               Southern California Commodore & Amiga Network
               http://www.sccaners.org

[Hydrophilic]

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.

[RobertB]

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. 

Its 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
               The Other Group of Amigoids
               http://www.calweb.com/~rabel1/
               Southern California Commodore & Amiga Network
               http://www.sccaners.org                 

[Hydrophilic]

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.

BTW, who is the author of ZED?  I would like to get his/her permission to distribute the modified version.  (if not, I can provide instructions on how one can modify it, only 2 bytes need changing)

[richardc64]

Google is your friend...

Craig Bruce
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

[megabit]

csbruce@cubewerx.com

[Hydrophilic]

Thanks for the info.  I have asked the master for his blessing!

...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

Your definition of simple is different from mine.  Thanks.  I've added a link to it on my website for anyone else who is as brave as you.