Q: RGBI (TTL) to VGA conversion - Experiences: MVC007 converter?

[DeaconBlue]

Hello!

I use an Apple IIc together with a Video-7 "IIc Color Enhancer" connected to a Commodore 1084S monitor supporting the 15,75 kHz RGBI/TTL (digital CGA mode) signal.

I am investigating possible RGBI to VGA -converters that could be used to hook-up up to a modern LCD-screen as an alternative to the ageing Commodore 1084S monitor.

I am aware of existing "analogue RGB" converters from Jammaboard (GBS-8220) and Ambery (15Khz RGB CGA/Component YCbCr to VGA Converter) which are reported to work with the Apple IIGS, but these do not support digital TTL mode.

I incidentally came across information on the web for a possible converter:

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MVC007 - CNC Monitor Replacement RGB,MDA,CGA,EGA to VGA Converter
- -

http://www.moncotech.com/cnc.php

Does anyone have any experience with this unit together with TTL /RGB outputs, or similar ready-to-use solutions not requiring custom PCB-wiring/soldering to do the conversion?


Any feedback appreciated!

[gid...@sasktel.net]

With all this talk of using vga monitors on the Apple II lately, someone should start a thread with some of the options out there to give others a chance to chime on their experience on that particular item.


Here are a few more convertors that may be an option

http://www.converters.tv/products/vga_to_vga/657.html
http://www.amazon.com/gp/product/B0051SLJAG?ie=UTF8&seller=A29A3B328VCPLO&sn=Dirt%20Cheap%20Trading
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=310413213761&item=310413213761&lgeo=1&vectorid=229466

[Steven Hirsch]

On 03/24/2013 08:55 AM, gid...@sasktel.net wrote:
> With all this talk of using vga monitors on the Apple II lately, someone should start a thread with some of the options out there to give others a chance to chime on their experience on that particular item.
>
>
> Here are a few more convertors that may be an option
>
> http://www.converters.tv/products/vga_to_vga/657.html
> http://www.amazon.com/gp/product/B0051SLJAG?ie=UTF8&seller=A29A3B328VCPLO&sn=Dirt%20Cheap%20Trading

The above two are the same device - one with a fancy red PCB.

> http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=310413213761&item=310413213761&lgeo=1&vectorid=229466

This is the Ambery converter.

None of these work very well with a IIgs. None will work at all with a IIe,
since they all lack a composite input.

[Steven Hirsch]

On 03/24/2013 04:32 AM, DeaconBlue wrote:

> I incidentally came across information on the web for a possible
> converter:
>
> - - MVC007 - CNC Monitor Replacement RGB,MDA,CGA,EGA to VGA Converter - -
>
> http://www.moncotech.com/cnc.php
>
> Does anyone have any experience with this unit together with TTL /RGB
> outputs, or similar ready-to-use solutions not requiring custom
> PCB-wiring/soldering to do the conversion?

At $190 USD I won't be the first to try it.

[DeaconBlue]

kl. 20:27:20 UTC+1 søndag 24. mars 2013 skrev Steven Hirsch følgende:
> On 03/24/2013 04:32 AM, DeaconBlue wrote:

>
> At $190 USD I won't be the first to try it.

- - - -
Dear Steve!

Thank you for your feedback! Yes, the price-tag is steep as there would not be a guarantee that it would work successfully.

I will check out a different option using a DB9 to SCART(RGB) 21-pin cable supplied from Germany. It is used for hooking up the Commodore 128 (80 col.mode (RGBI)) to TV-sets suporting this standard.
I believe the SCART-connector is called "Euro AV" in the states.

Check link: "Commodore C128 / C128D an TV Scart (80 Z. Color) "

http://www.ebay.com/itm/360605584795?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

As the IIc Color Enhancer carries output similar to that of the C128, it would be worth a try.

This is indeed not VGA-conversion, but provided the cable would give a decent reproduction on a LCD-TV, it could be worth looking into as an alternative screen replacement.

[Steve Nickolas]

On Mon, 25 Mar 2013, DeaconBlue wrote:

> I believe the SCART-connector is called "Euro AV" in the states.

I believe it's called "nonexistent" in the states, lol... I've never seen
anything that used it. o.o;

-uso.

[DeaconBlue]

OK, thank you for your feedback!

I also emailed Moncotech requesting information if the MVC007 converter would work. Here is the response:

- - -
Original message sent to xxxx...@icloud.com

We have a few customers before that uses similar machine and it should work for you after you feed the R,G,B, H sync, V sync signal into our MVC007 and it will automatically detect the frequency and generate the output.


Regards

Xiaoshuang(Wilson) Wang
Sales Manager
Moncotech
Phone: (607)348-4940
Site: www.moncotech.com



On Mon, Mar 25, 2013 at 12:50 AM, <xxx...@icloud.com> wrote:

Content: Hello Sir!

Would your CNC-converter work with the following input-signal:

- - -
TTL RGB @ 15 kHz/60 Hz (Digital CGA)
- - -

as used by legacy-standard color-monitors.

- IBM 5153
- Commodore 1084S

A

[Michael J. Mahon]

However, sweep frequency lock is only part of the problem. Video dot clock
lock is necessary to avoid the aliasing which mars so many scan converters
used with Apple II's.

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon

[Sean Fahey]

On Wednesday, March 27, 2013 9:29:39 AM UTC-5, Michael J. Mahon wrote:

> However, sweep frequency lock is only part of the problem. Video dot clock
> lock is necessary to avoid the aliasing which mars so many scan converters
> used with Apple II's.

Clueless person here... and how is that best tapped? Something on a slot, or a pin on the VGC?

[Michael J. Mahon]

A suitable sampler would be able to recover the dot clock just from the
video signal, though some monitors require some fine manual adjustment even
with PC video to get the best results.

In principle it should be quite easy with color Apple II graphics, since
the color burst is the same frequency (except for IIgs SHR). Text modes can
be tougher, but if the converter knows the approximate frequency, it should
be able to lock.

Feeding the slot 7MHz signal to the right place in a converter capable of
14.3MHz lock should make it solid as a rock.

[Steven Hirsch]

eBay is your friend. I picked up a few SCART cables from UK at reasonable prices.

The Samsung 730MW and 940MW are available on US eBay and both have a SCART
input for RGB+S video. The IIgs video looks quite good on them.

[fx]

Since that monitor will sync down to TV frequencies, could you put the IIgs on the VGA input?

[Steven Hirsch]

I haven't tried it, but my guess is no. VGA inputs tend to have a minimum
horizontal scan frequency of 31.5Khz.

[fx]

Yeah I know that that's the general rule, but some rare monitors are the exception. It seems worth trying. You can use a Mac 15 pin to VGA adapter, because the RGB and sync pins are in the same place on the IIgs.

[DeaconBlue]

Dear Steven!

Thank you for your response! If going for the SCART-cable solution to newer LCD-TVs or monitors with HDMI-only there are available fairly cheap SCART-to-HDMI ocnverters on Ebay

http://www.ebay.com/itm/belfan-brand-SCART-to-HDMI-converter-/121088093634?pt=US_Video_Cables_Adapters&hash=item1c3169adc2

I have not used the solution myself, but it could be worth a try also!

[DeaconBlue]

Just for the record, I did test the German SCART-cable intended for use
with the C128 / 80 column mode by connecting it to the DB9 port of the
Video7 IIc Color Enhancer. Regretfully, it didn't work out - producing
no image!

I cannot figure out why, as the Video-7 enhancer should produce a IBM CGA /
TTL -signaL (15,75 kHz.)

For those interested I have a picture of the actual Commodore 1084S monitor
connected to an Apple IIe with Video7 IIe Color Enhancer which delivers an
identical RGB-signal as the IIc-version . + a screenshot of the monitor
running "Choplifter"

weblink:

https://picasaweb.google.com/116494679368034210527/APPLE2?authuser=0&authkey=Gv1sRgCK-zyNXRq-vEjAE&feat=directlink





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"Steven Hirsch" skrev i nyhetsmeldingen:
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