TNC145 monochrome output to VGA?

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 13, 2021

• #1

Men

i Have a Bridgeport interact with the h.h TNC145 control, the monochrome monitor is getting almost to degraded to be able to see!
ive been thinking of converting it to run a VGA monitor this is my plan ....

i think i found the outputs as follows

57-30240 AMPHENOL CONNECTOR[/U]
23,24: +12V
21,22: Gnd
18,19: Video
16,17: Grey/Intensity
4,5: V-sync
2,3: H-Sync
6,7: Signal Gnd




i plan to chop and solder an old 14pin VGA cable as follows

ill attach h-sink and v-sink
The video output to green+
Signal ground to green-
and leave the rest unconnected

i think voltages on h-sin/v-sink will be ok, but im not sure about the video cable meshing up?

has anyone done this or knows what voltage/current im likely to see on the video output?

thanks

 

J

jz79

Stainless

Joined

Mar 21, 2017

Location

Latvia

• May 13, 2021

• #2

this shows how it should be done:

I did a mock up to test the circuit in case I ever need to change displays on my TNC155 and TNC355, it did work with TNC355 (did not test the 155) and the oldest lcd panel I could find but wasn't stable, maybe the signal level was low or the lcd didn't like the sync frequency - it would display the image for a second or two after switching on the lcd panel and then cut out with "no video signal" message, but while the image was there it was correct - bright letters on black background

 

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 13, 2021

• #3

That looks great , do you have a components list for an electrical dummy ?

 

G

gustafson

Diamond

Joined

Sep 4, 2002

Location

People's Republic

• May 13, 2021

• #4

It is an inverted MGA signal. If you hook a MGA monitor up to it, it will be inverted[bright screen dark letters, visible retrace]
It was the synch frequency IIRC that causes issues with VGA

hafta watch that video

still have a couple spare old monitors

 

G

gustafson

Diamond

Joined

Sep 4, 2002

Location

People's Republic

• May 13, 2021

• #5

THe 31.3 khz 58 hz displayed in the video seem like standard VGA numbers, which, I don't think, are what the Heidenhain are putting out. I assume the monitor is converting the signal to something it can use

 

J

jz79

Stainless

Joined

Mar 21, 2017

Location

Latvia

• May 13, 2021

• #6

I vaguely remember that the line frequency was around 31kHz coming out of TNC, at least the 355 I hooked the setup to

 

G

gustafson

Diamond

Joined

Sep 4, 2002

Location

People's Republic

• May 13, 2021

• #7

jz79 said:

I vaguely remember that the line frequency was around 31kHz coming out of TNC, at least the 355 I hooked the setup to

Click to expand...

I'think'the 355 is a different monitor

I hooked up the ooooooooooold monochrome monitor, which should be MGA, which should be like 17khz and it worked as I described, a readable image but inverted logic

Some monitors have a wide range of frequencies they will synch to, many will not go slow enough

The video the monitor has sync in the name, so I am thinking it is not a 50 dollar ebay monitor

There is discussion online about running old computers in new monitors, and it is rarely that simple

 

G

gustafson

Diamond

Joined

Sep 4, 2002

Location

People's Republic

• May 13, 2021

• #8

Converting MDA/CGA/EGA Graphics Output to VGA! - YouTube

MCE2VGA V2 - MDA (Monochrome) Hercules CGA or EGA to VGA Converter by Felipe Antoniosi - TexElec

 

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 14, 2021

• #9

Cheers gustafson those adapters will have to be modified though to get the 57-30240 AMPHENOL CONNECTOR to work.

Im going to crack on with my vga mod, working in the inverter diodes jz79 posted.
ive got a few old vga monitors i can pop if needs be!

 

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 17, 2021

• #10

Do you have the wiring diagram you show in this video ?
im not sure of the 57-30240 AMPHENOL pin outs now ?

cheers

 

G

gustafson

Diamond

Joined

Sep 4, 2002

Location

People's Republic

• May 18, 2021

• #11

Not my videos

There are service manuals available either in heidenhain.com or elsewhere that have schematics forthe TNC 145,151

 

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 19, 2021

• #12

yes i meant jz79

i had a go at the inverter circuit above couldn't get it to work for my tnc 145, i reckon the mce2vga would have worked though.

I ended up sweating off the glass from the cr tube, cleaning the injected glue film away and re-seating with adhesive silicone.
looks good

with much help form this guys vid .. CRT Cataracts: Identification, Removal and Repair - YouTube

putting it back on later fingers crossed it still works!

 

Z

zebbguy

Aluminum

Joined

Oct 19, 2020

• May 20, 2021

• #13

Before

After- much better !