Question about Z3 RAM and RTC

[PoulpSquad]

Good morning,

Not an issue for once, but a question about some quirk in WinUAE.

I was messing with some configuration, when I noticed something that seems strange to me.

When I set chipset=AGA Chipset extra=A1200, battery backed up RTC in Advanced Chipset is set to none.

Enabling Z3 RAM sets battery backed up RTC to MSM6242B (compatible settings still has a checkmark, Chipset extra is still A1200).

Config file has the following line in it:

RTC=none

Running Scout in the emulated Amiga shows there is a battery backed up RTC. Setclock reset and setclock save both work fine.

How can a device be both enabled and disabled? Why is a RTC mandatory when using Z3 (at least in WinUAE)?

Again, that's not an issue, but I'm genuinely curious about this.

Thanks a lot for your time and patience !

[Waccoon]

Did you mean Z2 RAM? The quickstart option enables the RTC when the configuration for fast RAM is used, since it was common for fast RAM cards for the A1200 to have a RTC. If I quickstart with a basic A1200 and manually set the CPU to 32-bit addressing and add Z3 RAM, the RTC option doesn't get enabled.

[PoulpSquad]

Hey Waccoon, thanks for your insight!

No, I mean Z3... my regular config is based around a 69020 (not EC).

I understand it was usual back in the day. What I don't get is why:

A) The option is automatically set when enabling fast RAM?

B) Why does is show as enabled (option is selected in GUI), but RTC is set as none in config file, AND configuration is still set as compatible A1200? If I select the same RTC option manually it becomes custom...

As I said it's not important, and I think you might be right. It might have been so usual to have RTC on memory expansion cards that UAE enables it by default when Z2/3 is enabled.

[thomas]

I would expect the specific options to be ignored when compatible is set. Just like in the GUI everything is greyed out unless you disable compatible.

And compatible probably is not fixed, it is made around what else you set (like RTC is enabled when extra RAM is added).

[PoulpSquad]

The RTC option isn't really ignored, it is very much enabled, as I can set time/date and save it with SetClock save and clear RTC with SetClock reset. Also Scout reports RTC present.

But I just noticed that although SetClock sets time ok, no NVRAM file is saved!

So I guess no error message =/= completed successfully.

That makes some sense, thank you for Waccoon and Thomas for your input.