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Posted By

tlr
on 2020-04-13
08:43:50
 Reliably detecting PAL vs NTSC?

Hi,

How do you reliably detect PAL vs NTSC on C16 and plus/4?
The $ff07 PAL bit doesn't seem to help here, at least not in vice.

Is there any best practice for this?

Posted By

Luca
on 2020-04-13
08:58:02
 Re: Reliably detecting PAL vs NTSC?

I see one single problem here: VICE.

Posted By

SVS
on 2020-04-13
09:06:53
 Re: Reliably detecting PAL vs NTSC?

Read the ROM at $FF80:

bit#7 = 1 is PAL
bit#7 = 0 is NTSC

Posted By

Csabo
on 2020-04-13
09:14:46
 Re: Reliably detecting PAL vs NTSC?

What SVS said is very reasonable. In practice, I'd say the vast majority of software just checks the $40 bit of $FF07.

Also, using VICE 3.4, the $FF07 bit behaves fine when I switch between PAL Plus/4 and NTSC Plus/4.

Posted By

tlr
on 2020-04-13
09:20:32
 Re: Reliably detecting PAL vs NTSC?

@SVS and Csabo: Good suggestions, thanks!

Interesting that it works in vice 3.4 with switching on-the-fly. Which platform are you running on?
I got problems with on-the-fly switching in vice (GTK3) built from the current trunk for Ubuntu 18.04 LTS. Maybe it's a regression?
I'll test with restarting the emu in between and see if that works.

Posted By

Luca
on 2020-04-13
10:09:23
 Re: Reliably detecting PAL vs NTSC?

Told you: VICE. Good luck.

OT: tlr, can we add a note to Rodmän with your name as Additional Code? I remember you coded its loader...

Posted By

tlr
on 2020-04-13
10:53:51
 Re: Reliably detecting PAL vs NTSC?

OT: sure. I did the tape loader + loading screen the rest is by Mika.

Posted By

tlr
on 2020-04-14
06:18:23
 Re: Reliably detecting PAL vs NTSC?

I ended up using the $FF07 bit + I've posted a bug report for vice here: http://sf.net/p/vice-emu/bugs/1210/ .



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