Hi Joe! Thank you again for the response!
I actually did not get to test this without the USB mouse adapter AND without the lightpen both plugged in. All other assumptions made below are correct. I should clarify that the mouse cursor just blinks ever so slightly/quickly when these tiny lines appear.
I did replace the lightpen and that solved the "continuous HIT" issue I was having earlier with the system, so I feel confident that was one part of this equation. Also took your advice and swapped cables to/from the monitor to the rear of the CMI - all cables seem to be fine.
Sent: Sunday, September 24, 2017 7:09 PM
To: Fairlight-CMI@yahoogroups.com
Subject: Re: [Fairlight-CMI] Faulty light pen issue
Frank,
Your horizontal flicker lines clue is very interesting. Let me make sure I understand:
1. With *no* USB mouse adapter connected, just CMI->Monitor
a. With lightpen connected to monitor, random tiny horizontal flickers are seen
b. With lightpen disconnected, *still* see tiny horizontal flickers
2. Connecting USB mouse adapter:
a. Same behavior as (1) above
b. When tiny horizontal flickers are seen, the USB mouse cursor disappears
Here's why this is interesting: If the USB mouse cursor disappears, that's because it "saw" the lightpen HIT signal go active. This is so you can use either the lightpen or the mouse: when you bring the lightpen to the screen, the mouse cursor automatically
turns off.
*That* makes me think that the HIT signal from the monitor to the CMI, independent of the lightpen, appears to be randomly and briefly going active.
That could be a poor/flaky connection. Since it sometimes "looks" like it goes active, I would also suspect the ground signal.
I would closely visually inspect the signals all the way from Q219 to the monitor, they go through several conenctors:
- BERG-style connector on Q219 to 2 small coax cables which go to 5-pin XLR on rear of CMI
- 5-pin XLRs at each end of monitor cable
- 5-pin XLR on monitor
- wiring inside monitor to lightpen connector
If it all *looks* OK, I would use a multimeter to measure the resistance all the way through for each signal and ground.
Maybe this is your problem rather than the lightpen itself!
Joe
---In Fairlight-CMI@yahoogroups.com, wrote :
---In Fairlight-CMI@yahoogroups.com, wrote :
Could you try:
- Keep the USB mouse adapter plugged in
- Unplug the lightpen from the Fairlight monitor (VDU)
And see if it still looks like HIT is stuck?
The USB mouse adapter will prioritize the HIT from the lightpen and hide the mouse cursor.
This is so you can switch back and forth between the lightpen and mouse.
If HIT or TOUCH are stuck active, that could confuse the mouse adapter.
Also, if HIT were stuck active, I would expect the entire display to be inverted. HIT works by XOR'ing (so inverting) the pixels that are being drawn.
If you are seeing a normal (non-inverted) display but no HIT, *and* you are on a IIX (not a I or a II), check to make sure that the Q219 connections are correct. The VDU cable has a blue band and goes to the upper connector on Q219, the lightpen cable has a white band and goes to the lower connector on Q219.
The upper Q219 connector *only* has video out, and the lower connector has video AND lightpen inputs. One of the original mouse adapter buyers had never had a lightpen, and those connections were reversed. As a result, he had video (since it is on both), but the mouse could not simulate the lightpen since it was connected to the video-only connector.
Fingers crossed!
Joe