Hi guys,

I managed to win a mint condition C128D off eBay. The thing looks like it is almost brand new, whoever owned it looked after it like a baby. It came with the manuals, disks plus some extra floppies and cartridges.

However, I have a problem. The RF out works perfectly. I have a C64 video-composite cable that only seems to produce monocrome images and when used on the C128D it produces rock-steady monocrome images in C128 and C64 mode.

I have a C64-S-video cable which I've used successfully with my C64C (until I got the Chameleon and used the VGA out) and I get this:

C128 Mode: Distortion at the top of the screen. Image moved to the left.


C64 Mode: Perfect!


Does anybody know what might be causing this? Does the C128 not like the s-video cable? Is there something wrong with a chip?

The workaround is to simply use the RF output when using C128 mode, but it is annoying.

Also, is there anything that takes the RGBi of the C128/C128D and allows it to be connected to a VGA port? I wouldn't mind being able to access 80 column mode.

Thanks in advance.

Darrin

Last edited by Darrin on 22-May-2012 at 12:21 AM.
Last edited by Darrin on 22-May-2012 at 12:21 AM.
Last edited by Darrin on 22-May-2012 at 12:20 AM.

_________________
AmigaOne X1000, A4000(T), A3000, A2000, A1200(T), A1200, A500, CD32, Minimig+ARM, FPGA Arcade, Chameleon64, C-One, C128, C128D, C64C, C64, VIC-20, CBM 8032, CBM4032, Efika, Ultimate64

@Darrin

I'd check your cable to make sure that the connections are wired correctly using this correct pinout...

http://www.allpinouts.org/index.php/Commodore_C128/C64C_Video

The monochrome problem sounds like the cable has only been wired for SVideo (LumA & Chroma) and the composite video pin is not connected...

The shifting of the image at the top of the screen could be caused by a number of things ranging from a poor or wrongly wired cable, the TV itself or a fault...

Best way to find out is to make or check and modify (if needed) your current cable to make sure it's wired correctly and test it in turn for both Composite and SVideo output...

_________________

@Franko

Thanks for the tips.

The cable that gives the monocrome output is a C64 Video-Composite cable, so the cable is probably at fault (not even sure where it came from).

The s-video cable displays the colour perfectly. It was just interesting that the C64 mode displays OK and not the C128 mode.

The only other TV I have with S-Video is in the bedroon and it means lugging an old 32" CRT across the house.

Another thing I could try is to attach the S-video to a VCR and use the composite output on the VCR to connect it to my display.

Last edited by Darrin on 22-May-2012 at 01:16 AM.

_________________
AmigaOne X1000, A4000(T), A3000, A2000, A1200(T), A1200, A500, CD32, Minimig+ARM, FPGA Arcade, Chameleon64, C-One, C128, C128D, C64C, C64, VIC-20, CBM 8032, CBM4032, Efika, Ultimate64

@Darrin

I have a couple of 128's and the connectors are probably identical to the 128D. I picked up a special cable (probably from ebay): one end is a 9-pin "D", which connects to the 128, and the other is round. The round end connects to a Commodore 1084s monitor, similar to the original Amiga 1080, but with additional connectors. I can get the 80-column mode. You can't get VGA without an adapter, if there is such a thing. I don't doubt your 128D is okay, you just need the right cables and monitor. The output from the RF adapter is meant to connect to a TV and won't give a good picture. The tearing at the top of the picture might be caused by interference. There is a round video connector in back of the 128 that outputs video and audio. You need another special cable that splits the outputs into 4 RCA-type plugs. It isn't a proprietary Commodore cable, so you might be able to get one from a cable supplier somewhere. The output from this is limited to 40 columns I think. As you can see there are several video options and it gets complicated. There is a separate chip that generates the 128 video modes. I think they call it the VIC-II chip. To really test it properly you need a Commodore monitor.

_________________
X5000 / microA1(OS4.1 FE U2) / CodeBench / Imagine / Blender
Lightwave 2019 / Microsoft Visual C++

@thinkchip

Unfortunately my A1081 monitor died a couple of years ago and I've been using PC monitors ever since (A2000, A3000, A4000 and A1200 all have SDFFs and the Minimigs display on VGA monitors).

From the round video out on the back I ahve 2 cables:

one seems to be wired wrong and gives monocrome on the composite. The other is the s-video (plus R/L audio).

Someone on AO thinks that there might be a CBM monitor for sale near me. I'm keeping my fingers crossed.

_________________
AmigaOne X1000, A4000(T), A3000, A2000, A1200(T), A1200, A500, CD32, Minimig+ARM, FPGA Arcade, Chameleon64, C-One, C128, C128D, C64C, C64, VIC-20, CBM 8032, CBM4032, Efika, Ultimate64

@Darrin

Wish you were closer to me... still got a US-spec 1070 monitor here doing nothing because my step-down converter is only 100W and this thing is rated at 1.1A on the sticker on the back. You can have it if you can collect it from Wales. :)

@Spirantho

LOL. Damn, the next time I come over to watch a Swansea or Cardiff match I might just hold you to that.

_________________
AmigaOne X1000, A4000(T), A3000, A2000, A1200(T), A1200, A500, CD32, Minimig+ARM, FPGA Arcade, Chameleon64, C-One, C128, C128D, C64C, C64, VIC-20, CBM 8032, CBM4032, Efika, Ultimate64

@Darrin

I have an old 12" or 13" Magnavox monitor that was apparently made for the 128[D]. It has connectors for both 40 and 80 column mode with a switch. The panel cover broke off. Also has a mono speaker input (RCA). I forget the model # but it had a sharp picture for its day.

The VGA on the 128 is called TTL.

You might get lucky with something like this for 80 column mode:
http://www.aliexpress.com/products/ttl-to-vga-converter.html

@Lou

Cheers Lou. I'll check that link out.

_________________
AmigaOne X1000, A4000(T), A3000, A2000, A1200(T), A1200, A500, CD32, Minimig+ARM, FPGA Arcade, Chameleon64, C-One, C128, C128D, C64C, C64, VIC-20, CBM 8032, CBM4032, Efika, Ultimate64