Strange issue with my Apple IIc

[PacManPlus]

Hey guys:

 

I kept my Apple IIc since I acquired it in 1984. I just recently tried to connect it (composite) to an LCD monitor that has a composite input. Strangely enough, the text screens do not show up on this monitor (reports 'no signal'), but once a graphics screen is displayed (i.e. a game, etc.) the image shows up. If I exit the game/program/whatever that has the graphics (hi-res) screen, the image disappears again.

 

I imagine that the signal isn't strong enough (when in text mode) to drive the composite image. Is there any way to fix this simply? Can I use one of the signals from the 15-pin video port instead? I looked up the pinout from that port but saw signals I had never heard of before.

 

Thanks,

Bob

 

(I also need to find a way to clean the head on my internal floppy drive - it hasn't been cleaned since 1986 or so)...

Edited January 20, 2015 by PacManPlus

[The Usotsuki]

I would have thought the only difference between the text and graphics modes, from the perspective of a display, is the color burst... strange that it would reject an image just for not having a color burst o.o;

[+save2600]

I wonder if your config would stand to benefit from an amplified signal? Could try one of these or maybe use a VCR between the Apple and monitor to see if that helps any.

 

http://www.amazon.com/BOSS-Audio-BVAM5-Amplifier-Outputs/dp/B00011KLSO/ref=sr_1_2?ie=UTF8&qid=1421761184&sr=8-2&keywords=composite+amplifier

 

http://www.amazon.com/RadioShack-Component-Distribution-Amplifier-1500320/dp/B004Z1SO9O/ref=sr_1_3?ie=UTF8&qid=1421761184&sr=8-3&keywords=composite+amplifier

 

http://www.amazon.com/Power-Acoustik-Video-Signal-Booster/dp/B00009W5KS/ref=sr_1_2?ie=UTF8&qid=1421761303&sr=8-2&keywords=composite+video+amplifier

[david__schmidt]

I would have thought the only difference between the text and graphics modes, from the perspective of a display, is the color burst... strange that it would reject an image just for not having a color burst o.o;

Not strange - and that's exactly the problem. "Modern" LCD displays are less forgiving of Woz's indiscretions than older TV sets. Bob - you could try with any other composite-in device you have in your house to verify.

 

Sometimes it helped to feed the signal through a VCR(!) as they tended to clean up the signal somewhat. One of those amplifiers might do some normalization, but I wouldn't count on it. Your best solution will be to find a more forgiving monitor.

[MarkO]

Not strange - and that's exactly the problem. "Modern" LCD displays are less forgiving of Woz's indiscretions than older TV sets. Bob - you could try with any other composite-in device you have in your house to verify.

 

Sometimes it helped to feed the signal through a VCR(!) as they tended to clean up the signal somewhat. One of those amplifiers might do some normalization, but I wouldn't count on it. Your best solution will be to find a more forgiving monitor.

 

This sounds like a nice simple project..

 

A NTSC booster, with a wider Tolerance Input, and a tighter Tolerance Output.

 

I would guess that PAL and SECAM don't have such Issues???

MarkO

[Osgeld]

its more up to the screen, I use my apple IIc all the time with quite possibly the cheapest LCD HDTV I could find (a 13 inch craig), works fine

Edited January 21, 2015 by Osgeld