Anyone ever attach a mono LCD to a PET?

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Anyone ever attach a mono LCD to a PET?

Ethan Dicks
Hi, All,

I am thinking of the loose/spare motherboards I have and was thinking
of packaging one or more of them into a working machine.  The standard
video is H-sync, V-sync, and "video" out, at the right frequencies for
640x200 (80 col) or 320x200 (40 col).  What I don't know is where to
find a mono LCD panel that accepts this as input.  I'm not concerned
about total display size (anywhere from a few inches up to 12" or
more) and since I don't need to make dozens of these, I can get away
with a recycled surplus product.  I'd like to stick with monochrome
for the sharpest display, but it may be easier to find loose color
LCDs these days.

Has anyone here experimented with user-attached LCDs?  Any model
numbers or feature lists to share?

Thanks,

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Steve Gray
Hi Ethan,
 
I have looked for mono lcd screens on ebay for exactly the same purpose and haven't had any luck. the occasional one would be listed but at ridiculous prices. I think you'd be better off with a color panel. VGA LCD monitors are quite cheap but these days it's hard to find one that syncs down low enough. I have an NEC 1550M unit that syncs down to 15kHz and I was hoping to try to hook that up to the pet somehow. I think you need to adjust the voltage levels though.
 
 The other option is to go with a TV-type LCD unit that accepts composite, and just make a small adapter to convert the PET signals to composite. You can buy a small pre-made board on ebay for $25, but it's really just a single chip that should only cost a buck or so.
 
Steve

From: Ethan Dicks <[hidden email]>
To: [hidden email]
Sent: Tuesday, May 8, 2012 2:31:35 PM
Subject: Anyone ever attach a mono LCD to a PET?

Hi, All,

I am thinking of the loose/spare motherboards I have and was thinking
of packaging one or more of them into a working machine.  The standard
video is H-sync, V-sync, and "video" out, at the right frequencies for
640x200 (80 col) or 320x200 (40 col).  What I don't know is where to
find a mono LCD panel that accepts this as input.  I'm not concerned
about total display size (anywhere from a few inches up to 12" or
more) and since I don't need to make dozens of these, I can get away
with a recycled surplus product.  I'd like to stick with monochrome
for the sharpest display, but it may be easier to find loose color
LCDs these days.

Has anyone here experimented with user-attached LCDs?  Any model
numbers or feature lists to share?

Thanks,

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Ethan Dicks
On Tue, May 8, 2012 at 2:46 PM, Steve Gray <[hidden email]> wrote:
> Hi Ethan,
>
> I have looked for mono lcd screens on ebay for exactly the same purpose and
> haven't had any luck. the occasional one would be listed but at ridiculous
> prices.

Obviously, I'm not interested in ridiculous prices.

> I think you'd be better off with a color panel. VGA LCD monitors are
> quite cheap but these days it's hard to find one that syncs down low enough.

A standard VGA panel will _not_ sync down to 15KHz, which is why I
wasn't looking at those.

> I have an NEC 1550M unit that syncs down to 15kHz and I was hoping to try to
> hook that up to the pet somehow. I think you need to adjust the voltage
> levels though.

Level adjustment is easy enough - a simple voltage divider, or MOSFET
circuit or possibly even a 4066 should do the trick.

>  The other option is to go with a TV-type LCD unit that accepts composite,
> and just make a small adapter to convert the PET signals to composite. You
> can buy a small pre-made board on ebay for $25, but it's really just a
> single chip that should only cost a buck or so.

I know how to build a composite adapter for the PET, but having done
it in the past, I was less than thrilled with the results (adjustment
fiddliness and picture that was not rock-steady and sharp, unlike a
"real" PET display).

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Ethan Dicks
In reply to this post by Steve Gray
On Tue, May 8, 2012 at 2:46 PM, Steve Gray <[hidden email]> wrote:
> I have an NEC 1550M unit that syncs down to 15kHz and I was hoping to try to
> hook that up to the pet somehow. I think you need to adjust the voltage
> levels though.

I found a datasheet that does _not_ mention 15KHz rate...

http://www.nec-display-solutions.com/p/download/pr/File/cp/Products/LCD/Supported/LCD-1550M/Datasheets/PDF-Datasheet-LCD1550M(english)_x_en.pdf?fn=LCD1550M-Datasheet-english.pdf

It claims 31.5-60 KHz, standard for VGA, and claims to support 640x480
up to 1024x768 with some intermediate resolutions, also standard for
VGA.  I don't see 320xAnything up there.

I have not run across any consumer-packaged color LCDs that provide
for timings below 640x480.  If there are any out there, I'd love to
look into them.

In the meantime, this reminded me that I have an ancient mono *EGA*
LCD on the shelf.  That might be adaptable with little effort.  I'll
have to go dig that out and post the results.

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Steve Gray
Ethan,
 
It's true, the specs for the 1550M do not list 15kHz but it does work. There are various discussions on the Amiga and Atari forums that list a variety of LCD VGA monitors that work. I've recently discussed this on the TorontoCBM list as well.
 
 
Another option is to get one of those arcade RGB converters that are basically scan-doublers. The go for about $18-30 on ebay and convert 15kHz to 30kHz for standard vga monitors. This might be the easiest solutions. You could feed the PET's video signal into the green input and simulate the PET display quite nicely I'd guess.
 
Example ebay auction #: 261019705843
 
Steve

From: Ethan Dicks <[hidden email]>
To: [hidden email]
Sent: Tuesday, May 8, 2012 2:59:10 PM
Subject: Re: Anyone ever attach a mono LCD to a PET?

On Tue, May 8, 2012 at 2:46 PM, Steve Gray <[hidden email]> wrote:
> I have an NEC 1550M unit that syncs down to 15kHz and I was hoping to try to
> hook that up to the pet somehow. I think you need to adjust the voltage
> levels though.

I found a datasheet that does _not_ mention 15KHz rate...

http://www.nec-display-solutions.com/p/download/pr/File/cp/Products/LCD/Supported/LCD-1550M/Datasheets/PDF-Datasheet-LCD1550M(english)_x_en.pdf?fn=LCD1550M-Datasheet-english.pdf

It claims 31.5-60 KHz, standard for VGA, and claims to support 640x480
up to 1024x768 with some intermediate resolutions, also standard for
VGA.  I don't see 320xAnything up there.

I have not run across any consumer-packaged color LCDs that provide
for timings below 640x480.  If there are any out there, I'd love to
look into them.

In the meantime, this reminded me that I have an ancient mono *EGA*
LCD on the shelf.  That might be adaptable with little effort.  I'll
have to go dig that out and post the results.

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Ethan Dicks
On Tue, May 8, 2012 at 3:23 PM, Steve Gray <[hidden email]> wrote:
> Ethan,
>
> It's true, the specs for the 1550M do not list 15kHz but it does work.

Interesting.  I never would have guessed.

> There
> are various discussions on the Amiga and Atari forums that list a variety of
> LCD VGA monitors that work. I've recently discussed this on the TorontoCBM
> list as well.
>
> http://www.freelists.org/post/torontocbm/Amiga-15kHz-LCD-monitor-followup
> http://www.best-electronics-ca.com/monadapt.htm
> http://eab.abime.net/showthread.php?t=51894

Nice.  That's very helpful (I also have Amigas).

> Another option is to get one of those arcade RGB converters that are
> basically scan-doublers. The go for about $18-30 on ebay and convert 15kHz
> to 30kHz for standard vga monitors. This might be the easiest solutions. You
> could feed the PET's video signal into the green input and simulate the PET
> display quite nicely I'd guess.

That is another possibility.  I do have a couple of standard 12" VGA
LCDs that run on 12V (external PSU) that would work well for this.

Thanks,

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Steve Gray
In reply to this post by Ethan Dicks
Hi again,
 
Heres a picture of  my NEC 1550M connected to a CDTV....
 
Steve

From: Ethan Dicks <[hidden email]>
To: [hidden email]
Sent: Tuesday, May 8, 2012 2:59:10 PM
Subject: Re: Anyone ever attach a mono LCD to a PET?

On Tue, May 8, 2012 at 2:46 PM, Steve Gray <[hidden email]> wrote:
> I have an NEC 1550M unit that syncs down to 15kHz and I was hoping to try to
> hook that up to the pet somehow. I think you need to adjust the voltage
> levels though.

I found a datasheet that does _not_ mention 15KHz rate...

http://www.nec-display-solutions.com/p/download/pr/File/cp/Products/LCD/Supported/LCD-1550M/Datasheets/PDF-Datasheet-LCD1550M(english)_x_en.pdf?fn=LCD1550M-Datasheet-english.pdf

It claims 31.5-60 KHz, standard for VGA, and claims to support 640x480
up to 1024x768 with some intermediate resolutions, also standard for
VGA.  I don't see 320xAnything up there.

I have not run across any consumer-packaged color LCDs that provide
for timings below 640x480.  If there are any out there, I'd love to
look into them.

In the meantime, this reminded me that I have an ancient mono *EGA*
LCD on the shelf.  That might be adaptable with little effort.  I'll
have to go dig that out and post the results.

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Ethan Dicks
On Tue, May 8, 2012 at 3:25 PM, Steve Gray <[hidden email]> wrote:
> Hi again,
>
> Heres a picture of  my NEC 1550M connected to a CDTV....
> http://www.6502.org/users/sjgray/collections/commodore/a_cdtv.jpg

Nice.  I miss my CDTV.  I bought one new for $800, then it was stolen
in a burglary less than 2 months later.  I did get full payout from
the insurance company, but I decided not to replace it at the time.  I
haven't seen any for sale in many years.  I do have a CD32 (presently
hooked up), but the CDTV had a nice component look to it that the CD32
lacks.

-ethan

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Re: Anyone ever attach a mono LCD to a PET?

Anders Carlsson
In reply to this post by Steve Gray
Steve Gray wrote:

> You could feed the PET's video signal into the green input and simulate
> the PET display quite nicely I'd guess.

Nice idea! I used to own one of those RGB to VGA converters, but as it
didn't fit my application (*) I sold it to a friend. Usually when it comes
to composite video one has a full colour signal so your approach would not
be very useful, but in the PET application it probably would work.

(*) I wanted to use it with my Amstrad MegaPC, that outputs a 31 kHz sigal
in DOS/PC mode and a 15 kHz signal in Sega Megadrive mode, both from the
same 15-pin connector. The boards listed on eBay claim they accept VGA
input, but apparently this is false information. When converting from 15 to
31 kHz, the board worked well but when "bypassing" 31 kHz it produced an
image that my VGA monitor couldn't sync to - perhaps 62 kHz or something
equally stupid?

Best regards

Anders Carlsson


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Re: Anyone ever attach a mono LCD to a PET?

Justin-2
The Magnavox 15MF605T/17 is a small LCD, cheap to get now that it is discontinued, and accepts composite, split composite, component, and VGA inputs.  I use one with my 128DCR.  I just wish it could accept the screwy almost-EGA output from the 128D.  I've never been able to use the 128D in 80 column mode, the adapters for that are pricey for what they do, which would be ok, but no one seems to like the output from them either, so I've never tried.

Justin

On May 8, 2012, at 15:41 , Anders Carlsson wrote:

> Steve Gray wrote:
>
>> You could feed the PET's video signal into the green input and simulate the PET display quite nicely I'd guess.
>
> Nice idea! I used to own one of those RGB to VGA converters, but as it didn't fit my application (*) I sold it to a friend. Usually when it comes to composite video one has a full colour signal so your approach would not be very useful, but in the PET application it probably would work.
>
> (*) I wanted to use it with my Amstrad MegaPC, that outputs a 31 kHz sigal in DOS/PC mode and a 15 kHz signal in Sega Megadrive mode, both from the same 15-pin connector. The boards listed on eBay claim they accept VGA input, but apparently this is false information. When converting from 15 to 31 kHz, the board worked well but when "bypassing" 31 kHz it produced an image that my VGA monitor couldn't sync to - perhaps 62 kHz or something equally stupid?
>
> Best regards
>
> Anders Carlsson
>
>
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Re: Anyone ever attach a mono LCD to a PET?

raycomp
i had (maybe still do) a simple 9 pin "d" to single RCA cable that  
allowed me to use a composite monochrome screen back in the '80's on  
my 128.

--Ray
On May 8, 2012, at 5:42 PM, Justin wrote:

> The Magnavox 15MF605T/17 is a small LCD, cheap to get now that it  
> is discontinued, and accepts composite, split composite, component,  
> and VGA inputs.  I use one with my 128DCR.  I just wish it could  
> accept the screwy almost-EGA output from the 128D.  I've never been  
> able to use the 128D in 80 column mode, the adapters for that are  
> pricey for what they do, which would be ok, but no one seems to  
> like the output from them either, so I've never tried.
>
> Justin
>
> On May 8, 2012, at 15:41 , Anders Carlsson wrote:
>
>> Steve Gray wrote:
>>
>>> You could feed the PET's video signal into the green input and  
>>> simulate the PET display quite nicely I'd guess.
>>
>> Nice idea! I used to own one of those RGB to VGA converters, but  
>> as it didn't fit my application (*) I sold it to a friend. Usually  
>> when it comes to composite video one has a full colour signal so  
>> your approach would not be very useful, but in the PET application  
>> it probably would work.
>>
>> (*) I wanted to use it with my Amstrad MegaPC, that outputs a 31  
>> kHz sigal in DOS/PC mode and a 15 kHz signal in Sega Megadrive  
>> mode, both from the same 15-pin connector. The boards listed on  
>> eBay claim they accept VGA input, but apparently this is false  
>> information. When converting from 15 to 31 kHz, the board worked  
>> well but when "bypassing" 31 kHz it produced an image that my VGA  
>> monitor couldn't sync to - perhaps 62 kHz or something equally  
>> stupid?
>>
>> Best regards
>>
>> Anders Carlsson
>>
>>
>>      Message was sent through the cbm-hackers mailing list
>
>
>        Message was sent through the cbm-hackers mailing list
>

---------------------------------------------------------------
|Raymond C. Bryan  651-642-9890 vox      | The battle is sometimes |
|Raymond Computer  651-642-9891 fax      | to the small for        |
|2402 University Ave   -email:  raycomp      | the bigger they are     |
|St Paul MN  55114    @visi.com          | the harder they fall.   |
|USA              Amiga - Commodore      |     -- James Thurber -- |
http://www.raymondcomputer.com
---------------------------------------------------------------





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Re: Anyone ever attach a mono LCD to a PET?

Justin-2
I tried making a cable to move the pins around and it did not work on the two remaining displays in my house that have a VGA input. AFAIK, the levels and signaling will not give you a color 80 column display on a VGA input without a signal adapter, so unless you have a 1902, you're kinda screwed, and I just don't have room for that on my desk.

Justin

On May 8, 2012, at 19:59, RayBryan <[hidden email]> wrote:

> i had (maybe still do) a simple 9 pin "d" to single RCA cable that allowed me to use a composite monochrome screen back in the '80's on my 128.
>
> --Ray
> On May 8, 2012, at 5:42 PM, Justin wrote:
>
>> The Magnavox 15MF605T/17 is a small LCD, cheap to get now that it is discontinued, and accepts composite, split composite, component, and VGA inputs.  I use one with my 128DCR.  I just wish it could accept the screwy almost-EGA output from the 128D.  I've never been able to use the 128D in 80 column mode, the adapters for that are pricey for what they do, which would be ok, but no one seems to like the output from them either, so I've never tried.
>>
>> Justin
>>
>> On May 8, 2012, at 15:41 , Anders Carlsson wrote:
>>
>>> Steve Gray wrote:
>>>
>>>> You could feed the PET's video signal into the green input and simulate the PET display quite nicely I'd guess.
>>>
>>> Nice idea! I used to own one of those RGB to VGA converters, but as it didn't fit my application (*) I sold it to a friend. Usually when it comes to composite video one has a full colour signal so your approach would not be very useful, but in the PET application it probably would work.
>>>
>>> (*) I wanted to use it with my Amstrad MegaPC, that outputs a 31 kHz sigal in DOS/PC mode and a 15 kHz signal in Sega Megadrive mode, both from the same 15-pin connector. The boards listed on eBay claim they accept VGA input, but apparently this is false information. When converting from 15 to 31 kHz, the board worked well but when "bypassing" 31 kHz it produced an image that my VGA monitor couldn't sync to - perhaps 62 kHz or something equally stupid?
>>>
>>> Best regards
>>>
>>> Anders Carlsson
>>>
>>>
>>>     Message was sent through the cbm-hackers mailing list
>>
>>
>>       Message was sent through the cbm-hackers mailing list
>>
>
> ---------------------------------------------------------------
> |Raymond C. Bryan  651-642-9890 vox      | The battle is sometimes |
> |Raymond Computer  651-642-9891 fax      | to the small for        |
> |2402 University Ave   -email:  raycomp      | the bigger they are     |
> |St Paul MN  55114    @visi.com          | the harder they fall.   |
> |USA              Amiga - Commodore      |     -- James Thurber -- |
> http://www.raymondcomputer.com
> ---------------------------------------------------------------
>
>
>
>
>
>      Message was sent through the cbm-hackers mailing list

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