Interfacing 128/128D RGBI to SVGA?

[+OLD CS1]

I will be putting my 128D system back together soon, but I no longer have the Commodore 2002 nor Apple monochrome monitors I used to use. I could use the monochrome composite output of the RGBI port and connect to my 20" Dell's composite input but I would rather have color.

 

Has anyone successfully connected the RGBI port of the 128 to an SVGA monitor? Is there a device for doing so?

[+OLD CS1]

Duh. Right after I posed this question I found this:

 

https://sites.google.com/site/h2obsession/CBM/C128/rgbi-s-video

 

Seems like a bit of work, but that should not dissuade any of us retro-hack-geeks, right? Though, I would prefer a boxed solution in the end.

[Rybags]

The biggest problem of your video output is that it's 16KHz horizontal rate, same as TVs.

Virtually all modern monitors won't work at that rate, generally expecting 30 KHz or more.

 

S-Video converter is probably your best bet aside from something like an old compatible monitor.

If going DIY it's probably not worth spending more than $30 as there's plenty of off-the-shelf types around starting slightly over that price.

[carlsson]

Bear in mind that on the C128, the S-Video and RGBI are not interchangable options. Rather from the VIC-II chip in both 40 column C128 and C64 modes, you get composite or S-Video, while the VDC chip in 80 column C128 mode outputs RGBI. That is to say, if you want to play colourful games, in particular C64 ones, you have no use of the RGBI output. Only for programs running in 80 columns, you can use it. Mostly productivity software, some graphic text adventures, perhaps a few other games or demos pushing the VDC chip.

[+sm3]

I will be putting my 128D system back together soon, but I no longer have the Commodore 2002 nor Apple monochrome monitors I used to use. I could use the monochrome composite output of the RGBI port and connect to my 20" Dell's composite input but I would rather have color.

 

Has anyone successfully connected the RGBI port of the 128 to an SVGA monitor? Is there a device for doing so?

 

These work great for 128 80 column (RGBI) video to VGA. You'll have to purchase a GBS-8220 (from eBay or some other source) and also make your own connector.

 

http://he-insanity.blogspot.com/2014/03/commodore-128-cga-video-dac-board.html

 

The builder of these boards sold them initially via (now defunct) commodore128.org site and then on lemon64.com. The design was initially created by someone else.

 

You can search for "Commodore 128 Video DAC Board Available" on lemon64.

[+OLD CS1]

 

These work great for 128 80 column video to VGA. You'll have to purchase a GBS-8220 and make your own connector though:

 

http://he-insanity.blogspot.com/2014/03/commodore-128-cga-video-dac-board.html

 

The person who makes these boards used to post on the now defunct commodore128.org site, but he also posted on the lemon64.com site. The design was initially created by someone else.

 

Well, you pay for quality, huh? About $100 total to connect my 128 up to my LCD. I was going to tackle this on my own, but it seems a lot of people have done a lot of homework, already, and there is little point in trying to re-invent the wheel. (I am, however, surprised to read the C128DCR composite output on the RGBI port reported as non-working as mine does -- I never checked, but maybe something was modified in my unit.)

 

I am hoping to bring up my CP/M system, plus a number of other utilities which require 80 column mode (GEOS 128, in particular.) So this is a worthwhile venture, but will probably wait a while. I have already made an DIN-8 to S-Video cable, so the 40 column and 64 modes work just fine with my monitor.

 

FWIW, I have two Dell 20" monitors which have composite, S-Video, SVGA, and DVI inputs. These things are awesome, though one has a squeal from either the inverter or the power supply. I am able to connect my Windows desktop, Amiga with Picasso IV, Commodore 64/128 (40 column,) and TI-99/4A to the same monitor.

 

Thanks for the pointer.

[+sm3]

Yeah, if you plan on using a 128 long-term, I believe it's worth it. I stocked up on several of these "Video DAC" boards and also several of the GBS-8220. I'm betting the 8220 will fail before the former

 

I updated my post above with the thread on lemon64 where they were sold.

 

Pretty sure he is building these by hand so that's where the cost increase comes from compared to the kit board.

[carlsson]

Don't know about the C128DCR, but at least my C128D in plastic version has 80 column monochrome video on a pin on the DE9 connector. However I don't know how good that signal is, or if your monitor would display it crisp enough, compared to the picture you get with RGB.

 

What annoys me a bit are all those monitors that indeed take composite video, S-Video, in Europe sometimes even SCART RGB, as well as VGA but the monitor itself won't sync if you feed a 15 kHz signal on the VGA input. It is non-standard yes, but those multi-sync monitors of the past used to support down to 15 kHz and if the monitor itself accepts that sync rate through other inputs, it doesn't seem unthinkable that it would grok 15 kHz analog RGB on the VGA input too.

[+sm3]

 

(I am, however, surprised to read the C128DCR composite output on the RGBI port reported as non-working as mine does -- I never checked, but maybe something was modified in my unit.)

 

 

I just re-read your post again. Maybe what they were calling composite is actually the RF out. It could be mistaken as that I suppose. The "video" round din connector should actually be s-video or chroma luma audio but of course you can just make a composite video cable from that connector too if you'd like.

[+OLD CS1]

I used the composite output of the RGBI port (I think on pin 9?) before on an old green Apple monitor. Worked great. Made the monitor squeal a lot, though. That was until I freed up a 2002 and used it. But I wound up tossing my 1080, 1084, and two 2002s because one had failed and I could not get anyone to take all or one of them even as a give-away! That and I did not think I would need them again (hind-sight, and all.)

 

I also made a connector which allowed me to use an old IBM PCjr monitor. Actually worked quite well. Found the adapter in storage the other day. Next time I am out there I will post a picture of it.

[+sm3]

OK cool. Never heard of anyone doing that before. I don't use my 80-column mode much, just with Merlin 128. I purchased an s-video cable for mine for the day when my 1902 stops working

[+OLD CS1]

QWKRR 128 was really nice in 80 column mode. As is Desterm. GEOS was awesome and I am looking forward to upgrading it with a couple of patches I picked up over the years (Y2K, multi-drive, etc.) Neat stuff.

 

I have TSDS I used on the 64. I believe there was a 128 version as well. All I ever used of it was the compiler, though. How is Merlin 128?

[+sm3]

...

How is Merlin 128?

 

I like it. It's menu driven, but the biggest factor for me was the documentation. I found the real manual for it on eBay. I still like to hold real books in my hand and I can't pass up buying the real book/manual for something I use when they are good condition.

 

I believe you can find the manual for both the 64 and 128 versions online in PDF format.

 

Actually Merlin 128 will not work in 40 column mode on the 128. It will start loading and then tell you to switch so I have no choice but to use it in 80 column.

 

I've been wanting to give Turbo Macro Pro a go on the 64. They have a nice cross compiler (TMPx) for the PC that uses the same syntax as the real 64 assembler.

 

And of course there is http://www.ajordison.co.uk/