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PAL console differences?


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#1 matthew180 OFFLINE  

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Posted Mon Jun 28, 2010 8:36 AM

I should know this, but I've never messed with a PAL unit so I don't want to assume anything. What are the primary differences between a PAL 99/4A and the NTSC unit? I know PAL has more vertical lines, but in reading the 9918A/9929A datasheet, it does not appear that the PAL units had any more lines available as far as the computer was concerned, i.e. the PAL unit was still 256x192 pixels / 32x24 characters. Do the PAL units simply have more vertical border or something?

I know the vsync interrupt is 50Hz vs. 60Hz, but is there anything else that is different? Was there any PAL specific software out there? Hmm, now I'm wondering how the console did the sound too, since the ISR is triggered by the VDP vsync interrupt, and the ISR plays the music. Is there a firmware difference to compensate for the sound, or is everything slightly slower?

Was the 99/4A even very big outside the U.S. market?

Thanks,
Matthew

#2 Opry99er OFFLINE  

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Posted Mon Jun 28, 2010 8:40 AM

I can't speak to the differences in systems, but the French market was HUGE for the TI-99/4a. :)

#3 retroclouds OFFLINE  

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Posted Mon Jun 28, 2010 11:43 AM

As far as I know, we don't have any means to detect if we are on a PAL or NTSC TI-99/4A.
The colecovision has a specific BIOS ROM address that contains "50" for PAL and "60" for NTSC.
That way software can easily figure out if it needs to adjust sound loops, timers, etc.

Guess one should be able to figure out the same by running a tight assembler loop in scratchpad memory counting VDP interrupts.
Dunno how well that would work on hacked TI-99/4A's, SNUG systems or Geneves.
I don't care as those ain't my target machines anyway.

For what it is worth: Pitfall just runs a tick slower on a PAL system.

#4 matthew180 OFFLINE  

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Posted Mon Jun 28, 2010 1:15 PM

I'm not necessarily trying to have a program figure out if it is running on a PAL vs. NTSC system. I was trying to determine if the PAL systems had any differences other than the 50Hz vsync, like a vertical resolution greater than 192 for example? I'm pretty sure the PAL 9929A did not have a better resolution, but I just want to make sure.

Matthew

#5 Willsy OFFLINE  

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Posted Mon Jun 28, 2010 1:20 PM

I should know this, but I've never messed with a PAL unit so I don't want to assume anything. What are the primary differences between a PAL 99/4A and the NTSC unit? I know PAL has more vertical lines, but in reading the 9918A/9929A datasheet, it does not appear that the PAL units had any more lines available as far as the computer was concerned, i.e. the PAL unit was still 256x192 pixels / 32x24 characters. Do the PAL units simply have more vertical border or something?

I know the vsync interrupt is 50Hz vs. 60Hz, but is there anything else that is different? Was there any PAL specific software out there? Hmm, now I'm wondering how the console did the sound too, since the ISR is triggered by the VDP vsync interrupt, and the ISR plays the music. Is there a firmware difference to compensate for the sound, or is everything slightly slower?

Was the 99/4A even very big outside the U.S. market?

Thanks,
Matthew


The PAL unit has a different clock crystal to generate the clocks for the VDP.

Auto sprites and auto music run a little slower on the PAL 4A's (the upside is the main thread (i.e. the BASIC interpreter/GPL runs a little faster as it has a larger window of opportunity).

You are correct, horizontal and vertical resolution are exactly the same. PAL has 625 scan-lines IIRC. Is it 525 for NTSC? Can't remember now...

You'll probably find that viewable part of a PAL screen is taller than an NSTC (ie the PAL has a smaller border).

Mark

#6 matthew180 OFFLINE  

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Posted Mon Jun 28, 2010 1:42 PM

That's what I wanted to know, thanks! :-)

Matthew

#7 humeur OFFLINE  

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Posted Tue Jun 29, 2010 2:11 PM

In France this no pal, in germany is pal.

in France the standard of tv is secam with the scart ( peritel )

http://www.commentca...itel-scart.php3 the text in French

http://utopia.knowar...ring/SCART.html in english
http://en.wikipedia.org/wiki/SCART in english

ti sell with the ti99 a interface peritel (scart) in rgb.

the ti99 german is a same to France just the video interface is diferent this is a pal modulator to connect on antenna tv.

the ti is sell for 256*192.

jean louis alias humeur

#8 retroclouds OFFLINE  

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Posted Tue Jun 29, 2010 11:26 PM

In France this no pal, in germany is pal.

in France the standard of tv is secam with the scart ( peritel )

http://www.commentca...itel-scart.php3 the text in French

http://utopia.knowar...ring/SCART.html in english
http://en.wikipedia.org/wiki/SCART in english

ti sell with the ti99 a interface peritel (scart) in rgb.

the ti99 german is a same to France just the video interface is diferent this is a pal modulator to connect on antenna tv.

the ti is sell for 256*192.

jean louis alias humeur



We bought our TI-99/4A systems (2) in Belgium and we had the PAL modulator (even though the TI-99/4A came in a box with french packaging).
Can you attach a picture how the TI-99/4A with scart connector looks like ?
I think the picture quality should be better as with the PAL anntenna thing ?

#9 Willsy OFFLINE  

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Posted Wed Jun 30, 2010 2:40 AM

We bought our TI-99/4A systems (2) in Belgium and we had the PAL modulator (even though the TI-99/4A came in a box with french packaging).
Can you attach a picture how the TI-99/4A with scart connector looks like ?
I think the picture quality should be better as with the PAL anntenna thing ?


My memories of the UK PAL Modulator are not good! There was massive loss on the left hand edge of the screen - 4 characters on the left, completely invisible!

Rubbish! :x

#10 humeur OFFLINE  

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Posted Wed Jun 30, 2010 11:17 AM

In France this no pal, in germany is pal.

in France the standard of tv is secam with the scart ( peritel )

http://www.commentca...itel-scart.php3 the text in French

http://utopia.knowar...ring/SCART.html in english
http://en.wikipedia.org/wiki/SCART in english

ti sell with the ti99 a interface peritel (scart) in rgb.

the ti99 german is a same to France just the video interface is diferent this is a pal modulator to connect on antenna tv.

the ti is sell for 256*192.

jean louis alias humeur



We bought our TI-99/4A systems (2) in Belgium and we had the PAL modulator (even though the TI-99/4A came in a box with french packaging).
Can you attach a picture how the TI-99/4A with scart connector looks like ?
I think the picture quality should be better as with the PAL anntenna thing ?


just a picture on ebay

http://webcache.goog...fr&client=opera

this interface is best that pal the signal is rgb

#11 sometimes99er OFFLINE  

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Posted Sat Jul 3, 2010 9:03 AM

You are correct, horizontal and vertical resolution are exactly the same. PAL has 625 scan-lines IIRC. Is it 525 for NTSC? Can't remember now...

You'll probably find that viewable part of a PAL screen is taller than an NSTC (ie the PAL has a smaller border).

My experience is that TI shows borders on PAL. Same thing with c64. Also the later Amiga typically had 200 scanlines for NTSC and 256 for PAL in the low resolution.

:)




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