VGA MODE for VGA_Demo.spin ?

Phillip Y.

I was able to use VGA_Demo.spin with my old sony triniton VGA monitor.
Now while on vacation, I am trying to use a LiteOn CM1565MCLR / Dell D1528-LS monitor,
it will not begin to display unless·I change to 21_000_000 hz vga_rate,
it is looks ok for a moment before the monitor recycles its startup.

Can this be used or is it pointless ?

What mode is originaly intended for VGA_Demo.spin

Full specifications are here http://support.dell.com/support/edocs/dta/65226/00000001.htm
Video Presets/Frequencies
Modes·· ·Resolution·· Horizontal·· Vertical
1·········· 720 x 400·· ·31.47 kHz·· ·70.08 Hz·
2·········· 640 x 480··· 31.47 kHz·· ·59.95 Hz
3·········· 800 x 600··· 46.87 kHz·· ·75 Hz
4········· ·640 x 480··· 37.5 kHz···· ·75 Hz
5·········· 640 x 480··· 37.86 kHz· · 72.81 Hz
6·········· 800 x 600··· 37.88 kHz·· ·60.32 Hz
7·········· 800 x 600·· ·48.08 kHz··· 72.01 Hz
8·········1024 x 768·· · 48.36 kHz·· 60 Hz
9········ 1024 x 768··· ·56.48 kHz·· 70.07 Hz
10······ 1024 x 768··· ·60.02 kHz·· 75.03 Hz
11······ 1280 x 1024· ·64.34 kHz··· 60 Hz

cgracey

Using the TV.spin and VGA.spin drivers, the pixel rate cannot exceed the clock/4. So, until you put in a crystal faster than 5MHz (which gets wound up to 80MHz), you will not be able to exceed a pixel rate of 20_000_000. I would suggest a 6MHz crystal. This way, your clock frequency can be 96MHz.

Phillip Y. said...

I was able to use VGA_Demo.spin with my old sony triniton VGA monitor.

Now while on vacation, I am trying to use a LiteOn CM1565MCLR / Dell D1528-LS monitor,
it will not begin to display unless·I change to 21_000_000 hz vga_rate,
it is looks ok for a moment before the monitor recycles its startup.

Can this be used or is it pointless ?

What mode is originaly intended for VGA_Demo.spin

Full specifications are here http://support.dell.com/support/edocs/dta/65226/00000001.htm
Video Presets/Frequencies
Modes·· ·Resolution·· Horizontal·· Vertical
1·········· 720 x 400·· ·31.47 kHz·· ·70.08 Hz·
2·········· 640 x 480··· 31.47 kHz·· ·59.95 Hz· THIS IS THE MODE!!
3·········· 800 x 600··· 46.87 kHz·· ·75 Hz
4········· ·640 x 480··· 37.5 kHz···· ·75 Hz
5·········· 640 x 480··· 37.86 kHz· · 72.81 Hz
6·········· 800 x 600··· 37.88 kHz·· ·60.32 Hz
7·········· 800 x 600·· ·48.08 kHz··· 72.01 Hz
8·········1024 x 768·· · 48.36 kHz·· 60 Hz
9········ 1024 x 768··· ·56.48 kHz·· 70.07 Hz
10······ 1024 x 768··· ·60.02 kHz·· 75.03 Hz
11······ 1280 x 1024· ·64.34 kHz··· 60 Hz

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Chip Gracey
Parallax, Inc.

LoopyByteloose

Chip.
I hate to ask this question but doesn't this imply that the Rev C Demo Board would support VGA better with the 6Mhz crystal?

I suppose I could easily remove the 5Mhz and install a socket to that end.
But it seems obvious that I would be overclocking unnecessarily high.
Maybe there is a 5.10Mhz Xtal or closer out there.

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"When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)

······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Phillip Y.

I tried adjusting various VGA parameters untill I found 21_000_000 and it only looks sort of ok for 2-3 seconds and this is with some extra vertical color box bars,
I beleve the program makes some funny calculations with 21_000_000 and this just happens to get the problem monitor to turn on with a display.
The VGA monitor is going through several of it's vga modes to try and lock on and after 10-15 seconds it locks up and goes in to powersaving mode.
I think that the problem is more one of a fussy monitor than changing the XTAL, since my old Sony monitor works fine and the problem monitor works ok with my laptop.

I am now using TV output so I am not concerned now.

John Culver

If you are using the old vga_demo.spin, then·the timing doesn't·match the normal VGA timings·closely enough to convince a lot of lcd and many CRT monitors. When I tweaked up the horizontal and vertical timings to match 480 line VGA, it worked much better, and all of the monitors I·connected·worked.

Then the next day Chip Gracey released the vastly improved vga_text_demo.spin in the archive·'vga_text_demo - Archive· [noparse][[/noparse]Date 2006[noparse][[/noparse]1].05.17· Time 02.32]' this one has much the same timings as I had changed to and worked beautifully for me too.

psavolai

I have the exact same problem with unsupported rate on my CRT.

Where can I find this "new and improved" vga-object that has better timing ?
I tried to look in the object exchange but it was not there .
pointers ?

petri.

cgracey

Petri,

Terve! Olen illoinen ett

psavolai

Terve Chip,

Pekka·sanoi tuntevansa sut ja kertoi hauskoja tarinoita niiltä ajoilta.
Hän myös lupasi mulle pullat ja kahvit jos saan VGA:n ruudulle jotain järkevää alle kahden viikon...
Taidanpa piipahtaa tampereella loppuviikosta lunastamassa lupauksen
Hän voisi varmaan ottaa propellerit edustukseen jahka näkee ensin yhden toiminnassa.

Thank You·Chip,

I appreciate your extremely quick response (... and the objects of course)
I'll give them a spin (·) and let you know how it works out.


Being an active PIC-programmer (CCS C) I just can't tell you how much I appreciate the
quick and painless development cycle associated with the propeller.
Great product.

regards,

petri.

psavolai

... later that evening.

So I tried the new objects and got the same results, just different looking unsupported rates this time.
(I'm am using Hitachi CM766ET monitor, and it should support quite a few modes)

So I thought I make sure:

1. I've built my vga-circuit according to Propeller Demo Board Rev B
Should I use rev C ?, where do I get that picture from ?

2. Is the vga-connector documented so that the "holes" in the female connector are facing the viewer ?

3. I left out the yellow leds and their 240ohm resistors , could that have an impact ?

4. has someone actually made this work outside parallax offices ?

hmm ... hoped that this would be easier.

petri.

CJ

1. the rev C schematic is on the demo board page

2. use the pin markings on your connector (should be shown)

3. no problem

4. built mine on a bit of perfboard, plugs in perfectly with my propstick on a breadboard, will post a pic if that would be useful

edit: looking into the female vga the pins are

5........1
10.....6
15.....11

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Who says you have to have knowledge to use it?

I've killed a fly with my bare mind.

Post Edited (CJ) : 6/20/2006 2:45:29 PM GMT

cgracey

psavolai said...
... later that evening.

So I tried the new objects and got the same results, just different looking unsupported rates this time.
(I'm am using Hitachi CM766ET monitor, and it should support quite a few modes)

So I thought I make sure:

1. I've built my vga-circuit according to Propeller Demo Board Rev B
Should I use rev C ?, where do I get that picture from ?

I've attached the Rev C schematic. The VGA circuit hasn't changed.

2. Is the vga-connector documented so that the "holes" in the female connector are facing the viewer ?

Yes.

3. I left out the yellow leds and their 240ohm resistors , could that have an impact ?

No.

4. has someone actually made this work outside parallax offices ?

I'm quite sure.

hmm ... hoped that this would be easier.

Yeah, me too. That monitor should be able to make sense of just about any VGA signal. I assume you've used pins 16..23 for your VGA signals. That would give compatibility with the existing source files. I hope you get this working soon. There shouldn't be any hang-up. Have you got a solid 3.3V supply for the Propeller?

petri.

To get the VGA timing info, I've always gone to this Finnish guy's site:

http://www.tkk.fi/Misc/Electronics/faq/vga2rgb/calc_v15.html



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Chip Gracey
Parallax, Inc.

psavolai

Hi guys,

I checked my LM2937ET with scope and it produces a really nice and clean 3.3 V
btw, I am trying to use the 640x480 mode.

There is something really funny going at at the horizontal sync.
When magnified I see that there are about 1.8 us negative pulses about 28 us apart,
but there's a huge ripple that fluctuates a lot.
see attached 3gp-video (if you have tools for viewing it, I was not able to convert it to anything else)

In fact I'm not too crazy about the ripple in the vertical sync as well.
See attached jpg

CJ , it would be really nice if you could post a picture of your setup .
I'm pretty sure this just some funny (not actually so funny anymore) cockup on my behalf
and maybe comparing to your functioning one would help me to identify the problem in mine.

regards,

petri.

CJ

here is a pic of my vga setup, if you rotate it 180 it matches the schematic left to right, with 220s subbed for 240s.
the last connection on the right is ground and is connected per the schematic, also lines up perfectly with the propstick ground in a breadboard. hot-melt glue is used with zeal to attach the port and to prevent shorts

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Who says you have to have knowledge to use it?

I've killed a fly with my bare mind.

psavolai

GOT IT !
GOT IT !
GOT IT !

thanks CJ.
I rechecked everything once more and found out that my VGA connector
had a broken pin 14, so the sync never got to the monitor.
I changed the connector and voila ... everything works fine
and I am happy as a pig in (expletive).

This is soooo coool.

thanks,

petri.

CJ

good to hear you got it working, I think the propeller has us all feeling the same way

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Who says you have to have knowledge to use it?

I've killed a fly with my bare mind.