Minimig (Amiga) core discussion

[drj3rk]

Original code haven't finished cache update from "other" side. So i've finished it. Now any update of RAM from chipset side will update the cache as well.
Because 64MB chip has 16MB per bank (unlike 32MB having 8MB per bank) there is a 8MB chunk in additional 32MB FastRAM laying in the same bank as ChipRAM so a bit slower. I think with cache enabled for ChipRAM the difference won't be noticeable for this 8MB chunk.

Just saw your main changelog. Just wanted to say nice work on the Amiga stuff! Not that I need 300+MB of Fast RAM, but it's still nice to know it's there. Maybe if there is RTG support some day that will come in handy.

[R4MS]

@sorgelig: Thanks for this great update. Was the switch to base 1000 in RAM size intentional? In the more traditional 1024 base the fast ram sizes should be 24MB, 56MB, 280MB and 312MB.

[Sorgelig]

@sorgelig: Thanks for this great update. Was the switch to base 1000 in RAM size intentional? In the more traditional 1024 base the fast ram sizes should be 24MB, 56MB, 280MB and 312MB.

Instead of 312MB you see 327MB in WB. 15MB difference I've thought it worth to mention an actual size.

[apolkosnik]

@Sorgelig, Thanks for the extra memory! It works like a charm!

[R4MS]

I'm used to think in base 1024, so I get slightly confused by odd numbers greater than 1.

[kolla]

This was a huge step, and so sudden... was just a couple of days ago that I realized 64MB module was an option, and now this... wow. Thank you so much!

[Gouky]

Nice progress.

I was wondering, would it be possible to get a variation of the core stripped of TG68k and that use FX68k instead with "just" a 68000 7mhz/14mhz option + fast memory?

That would be very handy to have that kind of variation.

Thanks

[TMA]

What i noticed this weekend:

Slamtilt with WHDLoad works only until core Version 20190502. On higher core Versions, when you want to load a pinball-table, the screens goes white and hangs.

Maybe it's the same with other games/demos too. Please try out.

Standard AGA 020 config:
https://github.com/MiSTer-devel/Minimig ... mig-config

[R4MS]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

[ericgus]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Of course now you said it, someone will .. and then ask about the issue.

[JimDrew]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Seriously? You do realize that this is THE most common mode that people run their AGA machines in? MUI and a slew of other Workbench enhancements are all geared around 8 bit mode.

[sardaukarsiet]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Wouldn't someone just starting out in Amiga emulation think 256 colors to be pretty normal?

[Grosbill]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Seriously? You do realize that this is THE most common mode that people run their AGA machines in? MUI and a slew of other Workbench enhancements are all geared around 8 bit mode.

Not with just 2 mb of chipram.

It's slow and takes up most of the system's chip memory. MUI and most Amiga enhancements are more geared towards RTG users anyway. Best use case for most people is either 16 or 32 colors mode. None of my AGA amigas are using a 256 colors mode because it's inneficient.

[apolkosnik]

...
Not with just 2 mb of chipram.

It's slow and takes up most of the system's chip memory. MUI and most Amiga enhancements are more geared towards RTG users anyway...

Now, it sounds like we need RTG on MiSTer.

[drj3rk]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Seriously? You do realize that this is THE most common mode that people run their AGA machines in? MUI and a slew of other Workbench enhancements are all geared around 8 bit mode.

Not with just 2 mb of chipram.

It's slow and takes up most of the system's chip memory. MUI and most Amiga enhancements are more geared towards RTG users anyway. Best use case for most people is either 16 or 32 colors mode. None of my AGA amigas are using a 256 colors mode because it's inneficient.

Valid point, but I personally don't know anyone that had a 1200 that didn't run in 256 color mode. It was kind of the point of having AGA back then.

For my MiSTer purposes it doesn't really matter one way or the other, but I think that mode is more widely used on AGA than one might think.

[Grosbill]

Seriously? You do realize that this is THE most common mode that people run their AGA machines in? MUI and a slew of other Workbench enhancements are all geared around 8 bit mode.

Not with just 2 mb of chipram.

It's slow and takes up most of the system's chip memory. MUI and most Amiga enhancements are more geared towards RTG users anyway. Best use case for most people is either 16 or 32 colors mode. None of my AGA amigas are using a 256 colors mode because it's inneficient.

Valid point, but I personally don't know anyone that had a 1200 that didn't run in 256 color mode. It was kind of the point of having AGA back then.

For my MiSTer purposes it doesn't really matter one way or the other, but I think that mode is more widely used on AGA than one might think.

There's a reason most icon distributions are optimized for 16 and 32 colors modes.

But if some people are using 256 colors depths on their AGA amigas, then by all means the issue should probably get fixed.

[BBond007]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are displayed.But since no one sane would use that many colors on the workbench, I guess we do not need to investigate the problem.

Seriously? You do realize that this is THE most common mode that people run their AGA machines in? MUI and a slew of other Workbench enhancements are all geared around 8 bit mode.

Typically AGA users without graphics boards would still run Wonkbench in 16 or 32 colors max. There are are optimized palettes that make Workench look great in 16 colors. Almost nobody in their right mind would run Workbench in 256 colors on AGA because it was just powerfully slow and used too much Chip RAM.

You can define different named public screens for applications that need more colors. For example, I would have IBrowse/Aweb in its own an 8bit screen independent of Workbench. Obviously screens on the Amiga can be dragged or switched via Amiga key + m/n.

Anyway, does this problem occur in NTSC/PAL interlaced modes or is is just the (more demanding) DBlPal, DBLNtsc & Multisync modes?

[kolla]

Someone brought to my attention that the internet connection at 115200 bits/second does not work reliably when 256 colors are.

Not really a Minimig/MiSTer issue, as this is also true for real Amiga. 115200 baud is simply not really reliable with the built in serial port at all, though you might be lucky when using a third party serial.device replacement, such as baudbandit. It is ok for terminal use, where a glitch here and there doesn't make it totally unusable, but for PPP or SLIP and TCP/IP, or zmodem transfers, it often means so much re-transmitting that it simply isn't worth it. Simply put, the built in Amiga serial port sucks. I typically use 57600 baud on "faster" 020+ systems, and 38400 baud on slower systems. I hope one day the Minimig core will feature an alternative means of networking, either "special" alternative serial port, or some sort of ethernet card emulation.

And to Jim - no, 8bit was/is _not_ the most commonly used screen depth for Workbench on AGA systems. The "MagicWB standard" which MUI and other SASG products adhered to, used only 8 pens, and with AGA there is a step in performance and features when you go from 4 to 5 bit display. The "AGA software flicker-fixer" MagicTV only works up to 4 bit (16 colours) screendepths, for example.

[JimDrew]

You must not be in the U.S. 8 bit (256 color) mode was the most common used Workbench screen. I had tens of thousands of customers in the U.S. that used this mode for their Amigas. It's the reason why I created the Workbench Window video driver for FUSION.

[Piacenti]

How to output 480p VGA signal on Minimig? The scandoubler 1 option gives me a black screen but works fine on other cores. Should I use the VGA scaler in this core? Please, I want Amiga on my CRT so much!

[Sorgelig]

How to output 480p VGA signal on Minimig? The scandoubler 1 option gives me a black screen but works fine on other cores. Should I use the VGA scaler in this core? Please, I want Amiga on my CRT so much!

You need a special Commodore monitor to handle all non-standard Amiga resolutions. Scandoubler is not supported in Minimig core.

[Piacenti]

How to output 480p VGA signal on Minimig? The scandoubler 1 option gives me a black screen but works fine on other cores. Should I use the VGA scaler in this core? Please, I want Amiga on my CRT so much!

You need a special Commodore monitor to handle all non-standard Amiga resolutions. Scandoubler is not supported in Minimig core.

Thanks, will try to find one.

[R4MS]

How to output 480p VGA signal on Minimig?

Setting

forced_scandoubler=1
composite_sync=1
vga_scaler=1

works for all my monitors. Also for those which can not deal with 15kHz.

[Piacenti]

How to output 480p VGA signal on Minimig?

Setting

forced_scandoubler=1
composite_sync=1
vga_scaler=1

works for all my monitors. Also for those which can not deal with 15kHz.

Really? Will try this now! I almost bought a 15khz monitor early today but I love my convencional Sony Trinitron 19!

Edit: Worked perfectly, thank you! Does the VGA scaler adds lag?

[Sorgelig]

Setting

forced_scandoubler=1
composite_sync=1
vga_scaler=1

works for all my monitors. Also for those which can not deal with 15kHz.

forced_scandoubler=1 is not used in Minimig.
composite_sync=1 is not really correct if you intend to output 31KHz. Most monitors need separate HSync/VSync, so it must be composite_sync=0