Re: Guru Meditation Exact Visual Specs

From: silverdr_at_wfmh.org.pl
Date: Fri, 12 Aug 2016 12:35:44 +0200
Message-Id: <ECF5D6C1-F193-4351-80A0-1713FA32EF29@wfmh.org.pl>
> On 2016-08-12, at 00:10, Christian Euler <chris@deepvoid.de> wrote:
> 
>> That's what I mean - what is the "default" (not set by Workbench). If there is no code for setting the mode to either PAL or NTSC and both ROM and hardware were shared between PAL and NTSC countries then how did it decide which mode to use for the Guru?
> PAL and NTSC machines use different Agnus chips:

Meaning the hardware was *NOT* shared. That explains, and the reason for my confusion was (example):

> 390544-01	IC 8375 [...]	AMIGA-500+ [PAL - presumably]
> 390544-02	IC 8375 [...]	NTSC A500+


I thought that if the chip has the same number then it's the same chip. And PAL vs NTSC would differ with something more noticeable than minor "revision" digit. More like 6567/6569. Which seem to be the case with 8361/8367 but I never encountered any 8361.

> 252125-01	IC 8361 AGNUS NTSC	AMIGA-1000
> 252362-01	IC 8367 AGNUS PAL	AMIGA-1000
> 318069-02	IC 8372 FATAGNUS	AMIGA-2000			
> 318069-03	IC 8375 HIRES AGNUS	2M A-3000
> 318069-10	IC 8375 R2 AGNUS HR	PAL SMT A-500+/A-600
> 318069-11	IC 8375 R2 AGNUS HR	NTSC SMT
> 318069-16	IC 8375 R01M HR AGNUS	PAL 65NS AMIGA-2000
> 318069-17	IC 8375 R01M HR AGNUS	NTSC 65NS AMIGA-2000
> 318069-18	IC SM CSG 8375R0 SUP	AGNUS
> 318070-01	IC 8370 R3 FAT AGNUS	NTSC AMIGA-500
> 318071-01	IC 8371 R1 FAT AGNUS	PAL AMIGA-500
> 390544-01	IC 8375 FAT AGNUS	AMIGA-500+
> 390544-02	IC 8375 AGNUS 2 MEG	NTSC A500+

BTW - the list is not [entirely] correct. For example I've seen tons of 8372s in A500s as well as tons of 8371s in A2000s. I recall I even upgraded a number of those, because 8372 was the first to allow 2MiB "chip" RAM and people wanted those. Huh, rusty memory…

> Older Agnus chips are either fixed to PAL or NTSC, never chips can be preconfigured by grounding a pin and/or switched via software.

And in such case, the pin sets the "default" mode, while changing a bit in the register can override it, right?

-- 
SD!


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Received on 2016-08-12 11:00:03

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