Help me identify this particular TRL (Royal Information Electronics) monitor

[jesolo]

I've recently picked up this monitor from a friend of mine.
At the rear it states that is was manufactured by Royal Information Electronics but, I'm not sure what the model number is or, what the exact specifications of the monitor is.
I know that is a colour monitor but, I'm not sure whether it also supports EGA.

I found a reference to a monitor that looks very close to this one with an indicated model number of CT-1469 (or just CT1469).
However, since there is no model number printed on the monitor, I'm not sure whether it's the same.
Another website indicates that the monitor is also EGA capable.
The horizontal positioning of the image is a bit off but, I'll look into this later. Is it possible that it's because the horizontal refresh rate of the CGA card is at 15 KHz & that it's trying to refresh at 21 KHz (EGA)?

 

[pcdata76]

A very easy method to determine the type without opening the case with 9-pin connector monitors is to check the continuity between pins 1 and 2. On CGA only monitors, both pin 1 and 2 is ground and there should be continuity between them. On EGA monitors, pin 2 is secondary red and there should be no continuity with pin 1. In some CGA only monitors, pin 7 may be missing on the connector too.

Horizontal positioning is something related with horizontal phase setting than frequency. There is a H-PHASE adjustment on the back. You can correct the position by adjusting it if something is not wrong inside.

 

[VileR]

Apologies for going off topic, but what CGA card is that? The ROM character set looks *very* nice and readable...

 

[pcdata76]

Apologies for going off topic, but what CGA card is that? The ROM character set looks *very* nice and readable...

Because it is set to 40-column mode (CGA40) It won't be that much readable at common 80-column mode. Anyway, card has a nice character set.

 

[jesolo]

A very easy method to determine the type without opening the case with 9-pin connector monitors is to check the continuity between pins 1 and 2. On CGA only monitors, both pin 1 and 2 is ground and there should be continuity between them. On EGA monitors, pin 2 is secondary red and there should be no continuity with pin 1. In some CGA only monitors, pin 7 may be missing on the connector too.

Horizontal positioning is something related with horizontal phase setting than frequency. There is a H-PHASE adjustment on the back. You can correct the position by adjusting it if something is not wrong inside.

Thank you for that tip - I'm going to see if this can help me identify whether it's just CGA or CGA & EGA.

You are correct - there is an H-PHASE adjustment knob on the back.
Unfortunately, despite me adjusting it either way, it didn't rectify the problem.
As you can see from the pictures, if I have text (or graphics) displaying over the full width of the screen, the left hand side of the screen actually displays almost in the middle (you can see this from the C:\> prompt).
When I DIR/W at DOS, the image starts to "run off the screen" and appears on the left hand side again.
When I try adjusting this with the H-PHASE knob, all I get is the image just "running off" further to the right hand side and "overlapping" again from the left hand side.

 

[jesolo]

Because it is set to 40-column mode (CGA40) It won't be that much readable at common 80-column mode. Anyway, card has a nice character set.

I actually tested this monitor on my Sperry HT (XT based) PC. The Sperry's colour monitor seems to be working fine but, I suspect that the CGA card in the Sperry PC might be a "higher resolution" card (similar to your Olivetti M24/AT&T 6300).
So, when you plug in a standard monitor, it might cause this display issue. However, someone I spoke to informed me that, if this was the case, then you would not see an image on the screen at all.

Best would probably be to test this on another XT clone with a standard CGA card and see what it looks like - otherwise, I will probably have to open up the monitor and peek inside to see if there isn't an internal adjustment somewhere on the PCB of the monitor.
PS: I did try Mode CO80 at the Command Prompt. Didn't change anything

 

[marcoexo]

I found a very similar monitor, but it has a 15 pin connector, it looks like gets normal h/v and signal directed to green input, the case is almost identical.
The issue is that when I connect to a pc it does not work so seem not compatible with modern vga (tried lowest res), the monitor seems to regularly turn on.

Being same brand and identical case... I'm wondering...

1) monitor is vga but is broken
2) It only accepts ttl signals using 15 pin connector
3) monitor accepts different freq I cannot deliver from modern pc

Is the 2) option possible ? were there any isa cards capable of delivering ttl through vga connector ??