mikesk8 Posted August 4, 2020 Share Posted August 4, 2020 Hi All, I have a new Atari 800, which I suspect was converted to PAL from NTSC. The SALT shows TIA:PAL and NTSC B rom. Everything seem to be working ok though. Is there any way to run a software test to detect it? I do not want to fully disassemble it yet :P Quote Link to comment Share on other sites More sharing options...
Rybags Posted August 4, 2020 Share Posted August 4, 2020 The key repeat rate is hard-coded so if the Antic from another system is present the key repeat will seem wrong. Properly converting any machine NTSC to PAL is usually a non-trivial thing since a proper PAL signal needs the 4.43 MHz crystal and extra circuitry that's usually not present on NTSC machines. ? PEEK(53268) should return 1 for a PAL GTIA, 15 for an NTSC one. Telling which Antic is present isn't quite as easy. In Basic the easiest way might be to just use the frame counter updated in VBlank. 10 POKE 20,0:POKE19,0 20 S=PEEK(20)+PEEK(19)*256 30 POS. 0,0 : ? S/50 ; " " ; 40 GOTO 20 Run that and compare against a watch after about 30 seconds. If it's running apparently too fast then it's got an NTSC Antic. Quote Link to comment Share on other sites More sharing options...
TGB1718 Posted August 4, 2020 Share Posted August 4, 2020 If it's working ok, why take it appart ? Just enjoy it Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 4, 2020 Author Share Posted August 4, 2020 5 minutes ago, TGB1718 said: If it's working ok, why take it appart ? Just enjoy it I fully agree and I am not planning to take it apart. Cool machine I just wanted to investigate more to know the history of my model better:) Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 5, 2020 Author Share Posted August 5, 2020 On 8/4/2020 at 11:29 AM, Rybags said: The key repeat rate is hard-coded so if the Antic from another system is present the key repeat will seem wrong. Properly converting any machine NTSC to PAL is usually a non-trivial thing since a proper PAL signal needs the 4.43 MHz crystal and extra circuitry that's usually not present on NTSC machines. ? PEEK(53268) should return 1 for a PAL GTIA, 15 for an NTSC one. Telling which Antic is present isn't quite as easy. In Basic the easiest way might be to just use the frame counter updated in VBlank. 10 POKE 20,0:POKE19,0 20 S=PEEK(20)+PEEK(19)*256 30 POS. 0,0 : ? S/50 ; " " ; 40 GOTO 20 Run that and compare against a watch after about 30 seconds. If it's running apparently too fast then it's got an NTSC Antic. I have run both tests and: 1) first test got 1 = PAL GTIA 2) the timing was exactly the same even after 60 sec = seems to be PAL Antic Then, SALT is showing TIA:PAL, but OS is NTSC. Is it possible it runs ok with all PAL components and NTSC OS? 1 Quote Link to comment Share on other sites More sharing options...
Rybags Posted August 5, 2020 Share Posted August 5, 2020 The main things that will be different are key repeat and the tables that control tape loading. Supposedly the tapes shouldn't have a problem though as there's meant to be 5% tolerance built into Pokey. If it actually is an NTSC OS though, the key repeat on a PAL system would be annoyingly slow. You should be able to pick it straight away. Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 5, 2020 Author Share Posted August 5, 2020 14 minutes ago, Rybags said: The main things that will be different are key repeat and the tables that control tape loading. Supposedly the tapes shouldn't have a problem though as there's meant to be 5% tolerance built into Pokey. If it actually is an NTSC OS though, the key repeat on a PAL system would be annoyingly slow. You should be able to pick it straight away. I will open ROM and check what do you mean by the key repeat? Quote Link to comment Share on other sites More sharing options...
Rybags Posted August 5, 2020 Share Posted August 5, 2020 You don't have to open anything. Just start with Basic or Memopad and hold a key down. Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 5, 2020 Author Share Posted August 5, 2020 (edited) 7 hours ago, Rybags said: You don't have to open anything. Just start with Basic or Memopad and hold a key down. I did a test - video attached. It looks ok to me. Does it mean my NTSC OS is not NTSC OS? The last video works in Firefox but not in Safari dont know how to fix it. IMG_2087.MOV IMG_2087.mp4 IMG_2087.mp4 Edited August 5, 2020 by mikesk8 Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 7, 2020 Author Share Posted August 7, 2020 It seems that my machine is PAL in the end with the NTSC B OS. The key repeat (video attached above - only last works in Firefox) was ok too. As I don't use tapes, but on SIO2SD and cartridges I don't see any challenges with NTSC OS on PAL machine. If I manage to get PAL OS I will compare again and let you know:) I'm curious if there are other people running NTSC OS on PAL machines and what are their conclusions? Quote Link to comment Share on other sites More sharing options...
+Larry Posted August 8, 2020 Share Posted August 8, 2020 Appears to have a really nice display on that TV/monitor. Does it use an adapter such as S-video to HDMI? Quote Link to comment Share on other sites More sharing options...
mikesk8 Posted August 8, 2020 Author Share Posted August 8, 2020 1 hour ago, Larry said: Appears to have a really nice display on that TV/monitor. Does it use an adapter such as S-video to HDMI? yes, I use s-video cable form Lotharek + retroTINK pro with HDMI output. The video quality is pretty nice Quote Link to comment Share on other sites More sharing options...
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