Subject: Analog RGB to Svideo or VGA conversion

From: "Tony Knerr" <[email-masked]>
Date: Tue, 16 Nov 2010 23:04:36 -0000

One of my Magnavox RGB monitors decided to put on a fireworks show this weekend, so it got me to wondering about replacements or other 
options.

People with RGB monitors don't want to part with them anymore, so 
they're getting quite expensive. :(

I found this video demo with an AMIGA kit which should work for our 
9938/9958 devices, and it's relatively inexpensive as a kit for $35:

http://www.youtube.com/watch?v=LDP8cvIXtFY

Link to supplier:

http://www.neobitz.com/

A similar device is here:

http://jrok.com/hardware/RGB.html

The aforementioned items will work on Svideo devices, of which most
TV's nowadays have jacks for. But will quality suffer?

The other option is this:

http://www.ambery.com/rgbcgatovgac.html

This device converts the RGB output to a VGA signal, and I've got a 
few VGA mionitors laying around, so that's not a problem. This device 
is a little pricey at $92, though, although I assume the quality of
the display will be a little better.

Whattayathink?

Tony

---

From: Marc Hull <[email-masked]>
Date: Tue, 16 Nov 2010 15:36:15 -0800 (PST)

Some FYI Tony....

A Friend of ours named Mathew is currently working on a new VDP replacement that will output to VGA.  It was demo'd  a couple of weekends ago in Chicago on a TI with great results.  He is also rumored to be working on the 9938 end of it for the Geneve (among others.)  This will give you a straight connection to a modern LCD monitor with a pin compatible chip replacement.  Thought you might want to know ;-)  

--- On Tue, 11/16/10, Tony Knerr <[email-masked]> wrote:

From: Tony Knerr <[email-masked]>
Subject: [TI994A] Analog RGB to Svideo or VGA conversion
To: [email-masked]
Date: Tuesday, November 16, 2010, 5:04 PM

  

options.

Link to supplier:

http://www.neobitz.com/

Whattayathink?

Tony

---

From: Tony Knerr <[email-masked]>
Date: Tue, 16 Nov 2010 18:58:41 -0500

I've seen the webpage with the discussion of the 9918 and the pic of the 
TI title screen displayed on the VGA monitor.
I would imagine that a daughterboard that plugs into a 9938/58 socket on 
a Geneve/TIM/EVPC/AVPC and outputs
VGA is several years away? Actually I was thinking of 'now' solutions, 
sharing my only monitor between the Geneve and
TI994P isn't very appealing. :(

Interesting thought - the TIM is already a daughterboard. What would a 
board plugged into _IT_ be called?
A Granddaughterboard? :)

Tony

On 11/16/2010 6:36 PM, Marc Hull wrote:
>
> Some FYI Tony....
>
> A Friend of ours named Mathew is currently working on a new VDP 
> replacement that will output to VGA.  It was demo'd  a couple of 
> weekends ago in Chicago on a TI with great results.  He is also 
> rumored to be working on the 9938 end of it for the Geneve (among 
> others.)  This will give you a straight connection to a modern LCD 
> monitor with a pin compatible chip replacement.  Thought you might 
> want to know ;-)
>

---

From: "jacques" <[email-masked]>
Date: Tue, 16 Nov 2010 20:17:58 -0400

Before you know it you can have a great-granddaughter board. <grin> I have 
three of those and they came to visit this weekend.

Regards,

Jacques

---

From: ti99_forever <[email-masked]>
Date: Tue, 16 Nov 2010 21:20:22 -0800 (PST)

Tony,

You could, of course, ask first if any of us want to part with our monitors! ;)

Actually, I may have some, in various states... (meaning of repair).

I just need to "thin out the herd", I have too much stuff still...

--- On Tue, 11/16/10, jacques <[email-masked]> wrote:

From: jacques <[email-masked]>
Subject: Re: [TI994A] Analog RGB to Svideo or VGA conversion
To: [email-masked]
Date: Tuesday, November 16, 2010, 7:17 PM

Regards,

Jacques

----- Original Message ----- 
From: "Tony Knerr" <[email-masked]>
To: <[email-masked]>
Sent: Tuesday, November 16, 2010 7:58 PM
Subject: Re: [TI994A] Analog RGB to Svideo or VGA conversion

>> monitor with a pin compatible chip replacement.  Thought you might

------------------------------------

Yahoo! Groups Links

---

From: fdos <[email-masked]>
Date: Thu, 18 Nov 2010 10:55:10 -0700

Tony,

I've suffered from this malady frequently.  I have two non-working 
Magnavox RGB monitors and two non-working Commodore 1084 RGB monitors. 
I think they're all repairable as they seem to all have power supply issues.

I thought I would get around to repairing them during this winter while 
I can do it in the garage, safely away from visiting grand-kids, but now 
I have my teenage grandson five days a week for home schooling, and too 
many of my Saturdays are already scheduled.

S-video is much better than composite video, but not as good as RGB or 
VGA.  It's a good way to go if you already have a monitor or TV with 
S-video input that you can use as a TI/Geneve monitor.  Otherwise, a VGA 
solution will be a better way to go.

My problem has just been making the necessary cables for what I now have 
on hand.  When my last Magnavox monitor died it took me a long time to 
get around to making a Geneve to NEC Multisync cable.  Which I did not 
get to sync until I changed the cable for sync on green, and that's not 
perfect as white is sometimes pink.

I also have the Ambery unit, but still haven't made the necessary 
cables, so I can try it on both my TI-99/4P and Geneve systems.  I've 
decided my teenage grandson needs to learn electronics or a least ways 
how to solder, so he can help me make cables and fix power supplies.

Bill S

---

From: Insane Multitasker <[email-masked]>
Date: Thu, 25 Nov 2010 03:49:04 -0600

Sounds like your monitor was upset you didn't make it to the Faire. Did it leave
any last 'words' on the screen as it fizzled away?  ;)

If it makes you feel any better, in true TI Faire fashion, one of my RGB monitors 
bit the dust that weekend.  Fortunately, ye olde faithful Magnavox 8cm515 is still 
chugging  along and survived another year of faire travel.   

> From: [email-masked]
> Date: Tue, 16 Nov 2010 23:04:36 +0000

---

From: ti99_forever <[email-masked]>
Date: Thu, 25 Nov 2010 01:54:11 -0800 (PST)

Again, I may have some replacements... monitors taking up space.

--- On Thu, 11/25/10, Insane Multitasker <[email-masked]> wrote:

From: Insane Multitasker <[email-masked]>
Subject: RE: [TI994A] Analog RGB to Svideo or VGA conversion
To: [email-masked]
Date: Thursday, November 25, 2010, 4:49 AM

---

From: Tony Knerr <[email-masked]>
Date: Thu, 25 Nov 2010 06:19:51 -0500

Thanks for the offer, but I think I'm going to go in the direction of 
'newer'.
Any RGB monitor at this point is probably not going to have a long life 
expectancy.
I managed to repair another Magnavox monitor I had in storage that had 
color problems,
a little degaussing with a bulk tape eraser straightened it out somewhat.
Opening it up showed the blue lead's trace had suffered heat damage and 
partially disintegrated.
A jumper wire on the trace provided me with a fully working monitor - 
for now.

I'm going to get one, and then another, of the Ambery converters as 
funds become available.
Funding was also the reason I didn't make it to the faire, I really 
wanted to get there this year. :(
I don't know if my monitor had a visible message as it died, as I was 
walking back from getting
a cup of coffee when I heard it's cry of death. ;)

Tony

On 11/25/2010 4:54 AM, ti99_forever wrote:
> --- On *Thu, 11/25/10, Insane Multitasker /<[email-masked]>/* wrote:
>
>
>     > One of my Magnavox RGB monitors decided to put on a fireworks
>     show this weekend, so it got me to wondering about replacements or
>     other
>     > options.
>     >
>
>
>

---

From: ti99_forever <[email-masked]>
Date: Thu, 25 Nov 2010 03:55:58 -0800 (PST)

Awe, come'on! I was even going to give it to you for free! ;)
Just pay shipping is all... (yes, shipping on a monitor is a bit much...)

--- On Thu, 11/25/10, Tony Knerr <[email-masked]> wrote:

From: Tony Knerr <[email-masked]>
Subject: Re: [TI994A] Analog RGB to Svideo or VGA conversion
To: [email-masked]
Date: Thursday, November 25, 2010, 6:19 AM

Thanks for the offer, but I think I'm going to go in the direction of 'newer'. 
Any RGB monitor at this point is probably not going to have a long life expectancy. 
I managed to repair another Magnavox monitor I had in storage that had color problems, 
a little degaussing with a bulk tape eraser straightened it out somewhat.
Opening it up showed the blue lead's trace had suffered heat damage and partially disintegrated.
A jumper wire on the trace provided me with a fully working monitor - for now.   

I'm going to get one, and then another, of the Ambery converters as funds become available.
Funding was also the reason I didn't make it to the faire, I really wanted to get there this year. :(
I don't know if my monitor had a visible message as it died, as I was walking back from getting
a cup of coffee when I heard it's cry of death. ;)

Tony

---

From: "Tony Knerr" <[email-masked]>
Date: Sun, 30 Jan 2011 00:37:59 -0000

Ok, here's an update. 

I got the Neobitz board today. 
http://neobitz.com/Pages/Mods/SystemMods.aspx

Hooked it up to a Geneve and a 15" LCD monitor via component inputs 
and - nuthin'!

So I tried the composite output, and got a funny looking screen with 
the wrong colors, but it was viewable. 

Did some research, the Neobitz board accepts negative composite sync,
the V9938 outputs positive composite sync (Thanks, Bob!)
Found this:
http://www.twobits.com/RGB/sync.html
So I desoldered a 74LS04 out of a dead TI, and Voila! I've got an 
acceptable output on the composite and S-Video outputs of the
Neobitz. 

The component connection still doesn't work, though. I'm guessing it 
needs a 'sync cleaner' added to the board. I'm waiting to hear back
from the developer of the board on that point, seems like a good
guy, hopefully this will work out.

The S-Video output is not bad, it's actually fairly clear, and will
be acceptable if no solution is forthcoming on the component output
problem.

I'll keep you posted.

Tony

---

From: Gregory McGill <[email-masked]>
Date: Sat, 29 Jan 2011 18:36:32 -0800

What did this cost?

Greg

---

From: "Tony Knerr" <[email-masked]>
Date: Sun, 30 Jan 2011 15:00:59 -0000

There are several different versions. I got the one with the component
output, so it was the most expensive at $85 + $5 shipping.
There are cheaper versions as well as a do-it-yourself kit.
There are also options like a sync cleaner and adjustable pots for
the rgb input levels, and it's looking like I need to add those to
get the component video part working.

Tony

---

From: "Tony Knerr" <[email-masked]>
Date: Sun, 30 Jan 2011 15:02:58 -0000

Just found the price list:

$85 - Neobitz (Component/SVideo/Composite) Fully Assembled
$55 - Neobitz-S (SVideo/Composite) Fully Assembled
$40 - Neobitz-S (SVideo/Composite) DIY Kit

Tony

--- In [email-masked], "Tony Knerr" <tonyknerr@...> wrote:
> --- In [email-masked], Gregory McGill <arcadeshopper@> wrote:
> >
> > What did this cost?
> > 
> > Greg
> >
>

---

From: "Tony Knerr" <[email-masked]>
Date: Fri, 11 Feb 2011 00:31:51 -0000

Another update, good news!

I added the LM1881 sync cleaner to the Neobitz board today.
A couple of capacitors, a resistor, and 2 jumpers are also necessary.
Also found a problem with the board layout, as pins 6 & 7 for the 
LM1881 are reversed, easily solved.

The component video output is quite clear. I would say it's 90% as 
clear as RGB, based on the S-video output being 75%. All in all a
quite good investment for the result. I still need to get 3 pots to
add to the circuit to see what the proper resistance for the RBG 
inputs on the board should be, but that's a minor matter.

I asked the designer of the board if he could build some for us to
the specs required for the Geneve or other 9938 TI devices, and am
waiting to hear back from him. Worst case is I could buy stock boards
from him and modify them for our uses, or you guys could do it yourselves.

Anyone interested?

Tony

---

From: fdos <[email-masked]>
Date: Mon, 14 Feb 2011 09:06:05 -0700

Tony,

I might be interested in a couple depending on final cost, and whether 
or not we will ever see a F38 replacement for the V9938 VDP.  There is a 
website http://sblive.narod.ru/ZX-Spectrum/V9938/V9938.htm with the VHDL 
source code, but AFAIK we only have one member who could create the FPGA 
under the license agreement, and he's still busy doing the F18A version.

Bill S

On 2/10/2011 5:31 PM, Tony Knerr wrote:
> Also found a problem with the board layout, as pins 6&  7 for the
> --- In [email-masked], "Tony Knerr"<tonyknerr@...>  wrote:
>>
>> Ok, here's an update.
>>

---

From: Tony Knerr <[email-masked]>
Date: Wed, 16 Feb 2011 16:49:55 -0500

I imagine Jeff would add about $5 to the cost of the board for 
installing the
sync cleaner parts, so add that to the $90 for the board and shipping.
 From there, it depends on how the individual would want to proceed.
You could just attach some connectors to it and find a way to supply it
with the 5 volts it needs and let it lay on the desk and it would cost 
little
more. Or you could put it in a box like I did and add a 5 volt regulator
to use the 12 volts coming from the Geneve audio/video connector to
power the board. That would add about $20 to the cost. I think the
problem folks might have is obtaining the 8 pin din plug at this point,
I was lucky to have one laying around. I had a 5 volt regulator, some
cable, a grommet, a small board for the regulator, and some standoffs
for the 2 boards also. I just had to purchase a box.

I've attached a couple of photos of my completed project, I think it turned
out pretty well.

Tony

---

From: fdos <[email-masked]>
Date: Wed, 16 Feb 2011 15:21:27 -0700

Thanks Tony,

I do have a number miscellaneous parts in bags here (in the house) and 
there (in the garage), and amongst those parts should be lots of 
resistors and capacitor, a few Radio Shack boxes, definitely voltage 
regulators of 5VDC and 12VDC, and I suspect a few 8 pin DIN plugs as 
I've made a few different ones for my Geneve systems over the years. 
I'm just not so good at it any more due to vision problems, but I may 
have to give it another shot.

I think the sync cleaner would be necessary for the best component 
output.  I may have to settle for just one unless you get a deal for a 
group buy.  BTW no photo attachments.

Bill S