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Question about ntsc video output

12 messages · 2005-02-27 → 2005-03-06 · Yahoo Group era · View archive on archive.org

Participants: Peter Z Lakatos, bflorindo, Jarek Adamski, Senen Racki, Don Dindang, Jack Boatwright, Louis Florit

Preserved from the Timex/Sinclair 2068 Yahoo Group (2001–2019), which is no longer online. Text reproduced from the archive.org archive; email addresses masked.

Messages

1. ts2068 power adapter

Peter Z Lakatos · Sun, 27 Feb 2005 15:46

Hi,

A quick introduction. I'm Peter Lakatos from Hungary. My first
computer was the Sinclair ZX81 in 1985 and I got my first Sinclair ZX
Spectrum+ in 1986. I loved this computers and I started a Zilog Z80
club in our town, but it was mainly Sinclair ZX Spectrum and
Enterprise 128K club.

Now I live in Toronto, Canada. I realized that the North american
Spectrum was the Timex Sinclair 2068. I really wanted one. I tried to
bid for them on the eBay, but I was always outbidded. After a few try
finally I won one. I was really happy. 


Yesterday I got the computer, but without the power adapter and
without any cable. I found the TS2068 Technical Manual on the web, but
it didn't show the right polarity of the adapter. It only says the "14
to 25V DC".

Does somebody know what is the right polarity and what is the right
voltage? Can I use regular commercial adapters for it?

I found two matching adapter for the computer and tried them, but
nothing came up on the TV. I am so sad... Maybe the adapter wasn't
100% compatible, but I suspect the unit is wrong, because it was sold
as "AS-IS".

Is it possible to repair it? Are there any more spare parts available?
Is it possible to repair them? Jarek can you do it?

Peter Lakatos

2. RE: [ts2068] ts2068 power adapter

Senen Racki · Wed, 2 Mar 2005 04:56:

Peter,



I live in Hamilton and work in Toronto.  I have a working 2068 that isn't for sale, but
also a "spare parts" unit that works only when you take it out of a fridge (probably a
circuit board break or marginal component).  I can lend you an authentic power adapter so
you can do a proper test.  If your unit can be repaired and just needs parts, maybe you
can scavenge something from my partially working one.  Sorry, I only dabble in electronics
as a hobby and wouldn't be qualified to do more than just troubleshoot the basics of your
unit.  Best I can do is an offer to lend a power supply and some parts.



Senen.



  _____  

From: Peter Z Lakatos [mailto:[email]] 
Sent: Sunday, February 27, 2005 10:47 AM
To: [email]
Subject: [ts2068] ts2068 power adapter





Hi,

A quick introduction. I'm Peter Lakatos from Hungary. My first
computer was the Sinclair ZX81 in 1985 and I got my first Sinclair ZX
Spectrum+ in 1986. I loved this computers and I started a Zilog Z80
club in our town, but it was mainly Sinclair ZX Spectrum and
Enterprise 128K club.

Now I live in Toronto, Canada. I realized that the North american
Spectrum was the Timex Sinclair 2068. I really wanted one. I tried to
bid for them on the eBay, but I was always outbidded. After a few try
finally I won one. I was really happy. 


Yesterday I got the computer, but without the power adapter and
without any cable. I found the TS2068 Technical Manual on the web, but
it didn't show the right polarity of the adapter. It only says the "14
to 25V DC".

Does somebody know what is the right polarity and what is the right
voltage? Can I use regular commercial adapters for it?

I found two matching adapter for the computer and tried them, but
nothing came up on the TV. I am so sad... Maybe the adapter wasn't
100% compatible, but I suspect the unit is wrong, because it was sold
as "AS-IS".

Is it possible to repair it? Are there any more spare parts available?
Is it possible to repair them? Jarek can you do it?

Peter Lakatos













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3. Re: [ts2068] ts2068 power adapter

Louis Florit · Wed, 2 Mar 2005 09:43:

Hello Peter, welcome to the list.  I found the following on my own
website (I can't remember everything off the top of my head...)

Power Requirements:
DVE power supply, 15 V at 1 Amp DC, and with the outside sleeve of the
plug positive and the inside negative.

Hope this helps!

L

> From: Peter Z Lakatos [mailto:[email]] 
>  Sent: Sunday, February 27, 2005 10:47 AM
>  To: [email]
>  Subject: [ts2068] ts2068 power adapter 
>  
>  Hi,
>  
>  A quick introduction. I'm Peter Lakatos from Hungary. My first
>  computer was the Sinclair ZX81 in 1985 and I got my first Sinclair ZX
>  Spectrum+ in 1986. I loved this computers and I started a Zilog Z80
>  club in our town, but it was mainly Sinclair ZX Spectrum and
>  Enterprise 128K club.
>  
>  Now I live in Toronto, Canada. I realized that the North american
>  Spectrum was the Timex Sinclair 2068. I really wanted one. I tried to
>  bid for them on the eBay, but I was always outbidded. After a few try
>  finally I won one. I was really happy. 
>  
>  
>  Yesterday I got the computer, but without the power adapter and
>  without any cable. I found the TS2068 Technical Manual on the web, but
>  it didn't show the right polarity of the adapter. It only says the "14
>  to 25V DC".
>  
>  Does somebody know what is the right polarity and what is the right
>  voltage? Can I use regular commercial adapters for it?
>  
>  I found two matching adapter for the computer and tried them, but
>  nothing came up on the TV. I am so sad... Maybe the adapter wasn't
>  100% compatible, but I suspect the unit is wrong, because it was sold
>  as "AS-IS".
>  
>  Is it possible to repair it? Are there any more spare parts available?
>  Is it possible to repair them? Jarek can you do it?
>  
>  Peter Lakatos

4. Re: [ts2068] ts2068 power adapter

Don Dindang · Wed, 2 Mar 2005 19:21:

Hi,

You can use regular apapter 9V-15V 1A-1.5A
About polarity, in is negative and out is posiive.
Or you can use zx spectrum adapter.
 Set TV to ch 2 or 3 (depend on switch position) or
use  video out.

Watchara 

--- Peter Z Lakatos <[email]> wrote:

> 
> 
> Hi,
> 
> A quick introduction. I'm Peter Lakatos from
> Hungary. My first
> computer was the Sinclair ZX81 in 1985 and I got my
> first Sinclair ZX
> Spectrum+ in 1986. I loved this computers and I
> started a Zilog Z80
> club in our town, but it was mainly Sinclair ZX
> Spectrum and
> Enterprise 128K club.
> 
> Now I live in Toronto, Canada. I realized that the
> North american
> Spectrum was the Timex Sinclair 2068. I really
> wanted one. I tried to
> bid for them on the eBay, but I was always
> outbidded. After a few try
> finally I won one. I was really happy. 
> 
> 
> Yesterday I got the computer, but without the power
> adapter and
> without any cable. I found the TS2068 Technical
> Manual on the web, but
> it didn't show the right polarity of the adapter. It
> only says the "14
> to 25V DC".
> 
> Does somebody know what is the right polarity and
> what is the right
> voltage? Can I use regular commercial adapters for
> it?
> 
> I found two matching adapter for the computer and
> tried them, but
> nothing came up on the TV. I am so sad... Maybe the
> adapter wasn't
> 100% compatible, but I suspect the unit is wrong,
> because it was sold
> as "AS-IS".
> 
> Is it possible to repair it? Are there any more
> spare parts available?
> Is it possible to repair them? Jarek can you do it?
> 
> Peter Lakatos
> 
> 
> 
> 
> 
> 
> 
> 
> 





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5. Question about ntsc video output

bflorindo · Wed, 2 Mar 2005 21:14:

Hi.

I moved from Portugal to the U.S. in 1995 and I really, really want to use a Sinclair Spectrum instead of a Timex TS machine.

I was wondering if someone from this group knows what has to be changed in order for Spectrum to output an NTSC video signal instead of a PAL one. Any ideas? TS2068 have an NTSC video modulator and Spectrums have a PAL video modulator. Is it possible to make the change?

I asked a friend to see if hardware modifications could be done. He's also part of this group and I'm waiting for his reply, but I've heard that something could be done by extracting the RGB signal from the edge connector. I know nothing about electronics but any information or advice would be much appreciated. Thank you!

Bruno (aka zx)

6. Re: [ts2068] Question about ntsc video output

Jack Boatwright · Wed, 2 Mar 2005 21:37:

Simply get a PAL => NTSC (or is it vice versa?) video converter. 
It will enable you to use the Spectrum with NTSC television, 
providing, of course, that you also have an appropriate power 
supply for the Speccy.

Jack

----- Original Message ----- 
From: <[email]>
To: <[email]>
Sent: Wednesday, March 02, 2005 9:14 PM
Subject: [ts2068] Question about ntsc video output


Hi.

I moved from Portugal to the U.S. in 1995 and I really, really 
want to use a Sinclair Spectrum instead of a Timex TS machine.

I was wondering if someone from this group knows what has to be 
changed in order for Spectrum to output an NTSC video signal 
instead of a PAL one. Any ideas? TS2068 have an NTSC video 
modulator and Spectrums have a PAL video modulator. Is it possible 
to make the change?

I asked a friend to see if hardware modifications could be done. 
He's also part of this group and I'm waiting for his reply, but 
I've heard that something could be done by extracting the RGB 
signal from the edge connector. I know nothing about electronics 
but any information or advice would be much appreciated. Thank 
you!

Bruno (aka zx)

7. Re: [ts2068] Question about ntsc video output

bflorindo · Wed, 2 Mar 2005 21:51:

Thank you so much for the quick reply :-D

I'm thinking about buying a PAL2NTSC converter on eBay, but it would be great to see a speccy directly connected to my tv without having to spend $40 in a converter :/

And I forgot to mention that I don't know what kind of ac adapter should be used. I'm not sure if those Radio Shack Ac adapters would do the trick. Maybe I'll be buying a 48k or +2 (they use the same kind of ac adapter), or maybe a +3.

Again, thank you for the quick reply!
  ----- Original Message ----- 
  From: Jack Boatwright 
  To: [email] 
  Sent: Wednesday, March 02, 2005 9:37 PM
  Subject: Re: [ts2068] Question about ntsc video output


  Simply get a PAL => NTSC (or is it vice versa?) video converter. 
  It will enable you to use the Spectrum with NTSC television, 
  providing, of course, that you also have an appropriate power 
  supply for the Speccy.

  Jack

  ----- Original Message ----- 
  From: <[email]>
  To: <[email]>
  Sent: Wednesday, March 02, 2005 9:14 PM
  Subject: [ts2068] Question about ntsc video output


  Hi.

  I moved from Portugal to the U.S. in 1995 and I really, really 
  want to use a Sinclair Spectrum instead of a Timex TS machine.

  I was wondering if someone from this group knows what has to be 
  changed in order for Spectrum to output an NTSC video signal 
  instead of a PAL one. Any ideas? TS2068 have an NTSC video 
  modulator and Spectrums have a PAL video modulator. Is it possible 
  to make the change?

  I asked a friend to see if hardware modifications could be done. 
  He's also part of this group and I'm waiting for his reply, but 
  I've heard that something could be done by extracting the RGB 
  signal from the edge connector. I know nothing about electronics 
  but any information or advice would be much appreciated. Thank 
  you!

  Bruno (aka zx) 



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8. Re: [ts2068] Question about ntsc video output

Peter Z Lakatos · Thu, 03 Mar 2005 07:11

Hi Bruno,

The Spectrum ULA produces PAL video signal instead of NTSC.
The modulator only makes RF output signal for the TV set from the video 
signal and it doesn't make any conversion and specially the PAL <-> NTSC 
conversion is not that simple like conversion between the PAL and SECAM 
signal, because the PAL standard put 50 half picture on the TV screen in 
every second, but the NTSC does 60 half pictures per second. A PAL full 
picture contains 625 line, but a NTSC full picture contains only 525 lines.

It is really not that simple to convert the video signal. The solution 
would be an new ULA circuit for the Spectrum, but it doesn't exist. Also 
need an different clock timing to this, because the different scan line 
frequency. That is why the American TS2068 contains a different chip 
called SCLD instead of the ULA. This SCLD chip creates both the RGB and 
the u,v,y signals for the LM1889N chip which makes the NTSC standard 
composite and RF output signal.

You cannot extract the RGB signal from the ZX Spectrum edge connector, 
because it doesn't have it. It contains only the composite video and the 
u,v,y signals. The TS2068 edge connector contains the RGB signals, but 
again the problem is that the ZX Spectrum send 50 half pictures per 
second and the NTSC TV set is waiting for 60 half pictures per second, 
that is the main difference. This is why the Portugues Timex machines 
(Timex Computer - TC2048 and TC2068) contained a modified ULA called "TS 
2068 PAL" as you can see on the picture on the 3rd page of the following 
.pdf file: http://www.retroreview.com/tc2048.pdf

The easiest way to have a newer TV which can show both the NTSC and PAL 
standards. Most of the new ones can do it.
And you always can return your converter if you don't like it if you 
will buy it in the RadioShack or the BestBuy. ;-)

Here are the details about the power adaptor what you are looking for: 
http://www.nvg.ntnu.no/sinclair/faq/pinouts.html#POWER

Good luck!
Peter Z Lakatos


[email] wrote:

> Hi.
>  
> I moved from Portugal to the U.S. in 1995 and I really, really want to 
> use a Sinclair Spectrum instead of a Timex TS machine.
>  
> I was wondering if someone from this group knows what has to be 
> changed in order for Spectrum to output an NTSC video signal instead 
> of a PAL one. Any ideas? TS2068 have an NTSC video modulator and 
> Spectrums have a PAL video modulator. Is it possible to make the change?
>  
> I asked a friend to see if hardware modifications could be done. He's 
> also part of this group and I'm waiting for his reply, but I've heard 
> that something could be done by extracting the RGB signal from the 
> edge connector. I know nothing about electronics but any information 
> or advice would be much appreciated. Thank you!
>  
> Bruno (aka zx)
>
> *Yahoo! Groups Sponsor*
> ADVERTISEMENT
> click here 
> <http://us.ard.yahoo.com/SIG98jhfjc/M)8184.6018725.7038619.3001176/D=groups/S05566162:HM/EXP09913395/A%93423/R=0/SIGel9gslf/*http://www.netflix.com/Default?mqso`190075> 
>
>
>
> ------------------------------------------------------------------------
> *Yahoo! Groups Links*
>
>     * To visit your group on the web, go to:
>       http://groups.yahoo.com/group/ts2068/
>        
>     * To unsubscribe from this group, send an email to:
>       [email]
>       <mailto:[email]?subject=Unsubscribe>
>        
>     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>       Service <http://docs.yahoo.com/info/terms/>.
>
>

9. Re: [ts2068] Question about ntsc video output

Jarek Adamski · Thu, 3 Mar 2005 11:33

Cytowanie [email]:

> I was wondering if someone from this group knows what has to
> be changed in order for Spectrum to output an NTSC video
> signal instead of a PAL one. Any ideas?
Sorry, but nothing can be done. The internal circuit of
ULA generates frames of 312 lines and each one takes
1/50s. To get NTSC signal, you need to cut out 50 lines
from every frame (to get 262 lines) and insert one dummy
frame (probably with duplicated content) after every 5th
one.

It is not possible to force the ULA to do this job. An
external, advanced graphics device with buffers and line
cutter is needed.


> TS2068 have an NTSC video modulator and Spectrums have
> a PAL video modulator.
Yes, the PAL encoder could be replaced by SECAM encoder,
as both use the same frame structure at B&W signal level.
But NTSC has differen frame structure at B&W level than
PAL. The encoder makes Composite Video signal from RGB
signal. The modulator makes high frequency RF signal
from Composite Video one (and has no influence to frame
structure or the way the color is encoded).


> Is it possible to make the change? (..) but I've heard
> that something could be done by extracting the RGB
> signal from the edge connector.
Well, it is possible to use the NTSC encoder with the RGB
signal generated by ZX Spectrum. But you will get 50 fps
of 312 lines only with the colour encoded like NTSC. And
the TV set still must be able to display such frequency
(50Hz). Does this help?


The ULA in Timex Computer 2048/2068 has two modes - it
can be switched to generate PAL or NTSC frames. I don't
have much experience in this matter. I only shorted one
jumper on TC2048 board and it seemd to generate NTSC
frames (color encoding is separate thing).


The ZX48, ZX128, ZX+2, TC2048, TC2068 need +9V/1.5A DC,
while for ZX+2A, ZX+2B, ZX+3 and Sam Coupe an ordinary
PC AT power supply can be used (+5V, +12V, -12V).

--
Jarek Adamski

10. Re: [ts2068] Question about ntsc video output

Peter Z Lakatos · Thu, 03 Mar 2005 15:40

Hi Bruno,

The Spectrum ULA produces PAL video signal instead of NTSC.
The modulator only makes RF output signal for the TV set from the video
signal and it doesn't make any conversion and specially the PAL <-> NTSC
conversion is not that simple like conversion between the PAL and SECAM
signal, because the PAL standard put 50 half picture on the TV screen in
every second, but the NTSC does 60 half pictures per second. A PAL full
picture contains 625 line, but a NTSC full picture contains only 525 lines.

It is really not that simple to convert the video signal. The solution
would be an new ULA circuit for the Spectrum, but it doesn't exist. Also
need an different clock timing to this, because the different scan line
frequency. That is why the American TS2068 contains a different chip
called SCLD instead of the ULA. This SCLD chip creates both the RGB and
the u,v,y signals for the LM1889N chip which makes the NTSC standard
composite and RF output signal.

You cannot extract the RGB signal from the ZX Spectrum edge connector,
because it doesn't have it. It contains only the composite video and the
u,v,y signals. The TS2068 edge connector contains the RGB signals, but
again the problem is that the ZX Spectrum send 50 half pictures per
second and the NTSC TV set is waiting for 60 half pictures per second,
that is the main difference. This is why the Portuguese Timex machines
(Timex Computer - TC2048 and TC2068) contained a modified ULA called "TS
2068 PAL" as you can see on the picture on the 3rd page of the following
.pdf file: http://www.retroreview.com/tc2048.pdf

The easiest way to have a newer TV which can show both the NTSC and PAL
standards. Most of the new ones can do it.
And you always can return your converter if you don't like it if you
will buy it in the RadioShack or the BestBuy. ;-)

Here are the details about the power adapter what you are looking for:
http://www.nvg.ntnu.no/sinclair/faq/pinouts.html#POWER

Good luck!
Peter Z Lakatos


[email] wrote:

> Hi.
>  
> I moved from Portugal to the U.S. in 1995 and I really, really want to 
> use a Sinclair Spectrum instead of a Timex TS machine.
>  
> I was wondering if someone from this group knows what has to be 
> changed in order for Spectrum to output an NTSC video signal instead 
> of a PAL one. Any ideas? TS2068 have an NTSC video modulator and 
> Spectrums have a PAL video modulator. Is it possible to make the change?
>  
> I asked a friend to see if hardware modifications could be done. He's 
> also part of this group and I'm waiting for his reply, but I've heard 
> that something could be done by extracting the RGB signal from the 
> edge connector. I know nothing about electronics but any information 
> or advice would be much appreciated. Thank you!
>  
> Bruno (aka zx)
>
> *Yahoo! Groups Sponsor*
> ADVERTISEMENT
> click here 
> <http://us.ard.yahoo.com/SIG98jhfjc/M)8184.6018725.7038619.3001176/D=groups/S05566162:HM/EXP09913395/A%93423/R=0/SIGel9gslf/*http://www.netflix.com/Default?mqso`190075> 
>
>
>
> ------------------------------------------------------------------------
> *Yahoo! Groups Links*
>
>     * To visit your group on the web, go to:
>       http://groups.yahoo.com/group/ts2068/
>        
>     * To unsubscribe from this group, send an email to:
>       [email]
>       <mailto:[email]?subject=Unsubscribe>
>        
>     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>       Service <http://docs.yahoo.com/info/terms/>.
>
>

11. Re: [ts2068] Question about ntsc video output

Jarek Adamski · Sun, 6 Mar 2005 00:00

Cytowanie Peter Z Lakatos <[email]>:

> You cannot extract the RGB signal from the ZX Spectrum
> edge connector, because it doesn't have it. It contains
> only the composite video and the u,v,y signals.
But Spectrums like 128K, +2 and +3 have the RGB output
from ULA, as TEA2000 encoder is used in place of LM1889
that uses UVY.

> The easiest way to have a newer TV which can show both the
> NTSC and PAL standards.
But there are PAL >>> NTSC recorders that decode PAL
into RGB and then encode color into NTSC without any
influence to frame structure. One of them can be
found here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5755355037

Product Features:
Converts any PAL into a NTSC signal
Input: PAL A/V system
Output: NTSC A/V system
For video game systems (PS2, XBOX, GameCube),
  DVD player, VCR and other AV equipment
Composite video in and out
Comes with a 100v-240v power supply
Only works on the NTSC 50Hz compatible TV, auto sync
  TV or NTSC TV with a V-hold button


All the encoders used in ZX Spectrum and Timex Computers
(LM1889, MC1377, TEA2000) can be reconfigured to produce
NTSC encoded color, what should give color picture on
every TV set capable to display 50Hz / 312 lines frames.

However, the TV set can be tested with PAL signal - the
picture should be black&white, but stable (not moving
up/down or jumping). Also, RGB output should give nice
color picture.

--
Jarek Adamski

12. Re: [ts2068] ts2068 power adapter

Peter Z Lakatos · Sun, 06 Mar 2005 09:04

>Hello Peter, welcome to the list.  I found the following on my own
>website (I can't remember everything off the top of my head...)
>
Thanks Louis. I check your excellent website almost every day. I found 
it very helpful. It gave me the first kick into the TS2068 direction.

Peter Z Lakatos

Indexed under

TS2068 / TC2068 · Video upgrades (composite, RGB, HDMI) · Repair & restoration