Posts by iljitsch

1366x768 is not a great resolution... It's too high for 1 x, but too low for 2 x. I 1920x1080 is much better as you can have PAL x 2 and have 540 lines, which is 512 plus an amount of overscan that the Amiga can easily handle. I've had some success with 960x540 that fills up the entire screen, but I now mostly use 720x540 with black bars on the side.

I guess with 1366x768 I'd try setting that up for 2 x for the Workbench so that would be 683x384, a bit low but workable. Or tweak 1024x768 to show the correct black bars with no stretching. I've got that working for 720x540x2 = 1440x1080 so it should also be possible for 1024x768. Then perhaps set the overscan to a lower resolution to allow for more chip RAM access for the CPU. But for any PAL or NTSC games I don't see any way around a non-integer resolution.

Quote from Jens

Please try different output sampling frequencies. We've had the topic before, and depending on the capture device you need to change the sampling frequency. So far, most devices were compatible with 96kHz, but some required 44.1kHz.

I tried everything I could think of, and nothing worked. (Rebooting, different computers, different cables, different settings, I even downgraded the MK3 firmware.)

It seems my CamLink 4K is very picky about timings, and maybe it doesn't properly recognize the audio where my monitor does. You basically get a small beep every second or so. But after changing resolutions, the sound is more recognizable for half a second or so. It's all very strange.

Actually I just used a dB meter app on my iPhone which tells you the decibels coming in to the iPhone microphone.

But I took the above as a challenge. So I created a 440 Hz test tone WAV file, and played it back on the Amiga through its line out and HDMI as well as from a Mac using HDMI using another Mac's line in to record. I didn't bother setting the gain to anything specific, so don't pay attention to the absolute volume. Results:

Amiga HDMI: -20.041 dB

Amiga line out: -12.866 dB

Mac: -7.425 dB

So the HDMI out is still 8 dB lower than the Amiga line out and 12 dB lower than the Mac. So it's strange that at this level you are getting close to clipping. I used Play16 and didn't pay attention to the settings so maybe it wasn't playing back at max volume, though. But of course that equally applies to the Amiga line and HDMI outs.

(I can upload the recordings if that's helpful.)

I should have thought of checking whether the Mac uses 16, 20 or 24 bits, but I just plugged back all the cables... Still, if the Mac uses more bits then those should be at the low end, not at the high end so the volume can get louder without clipping...

I also tried to record the audio digitally through my HDMI capture dongle, but for some reason the audio didn't come through.

Audio seems to be about 6 dB louder, still about 6 dB less than Amiga line out and other HDMI sources.

By the way, this is definitely the proper way to use an Amiga 1200 in 2021: with a 4K monitor over HDMI, a wireless mouse and a USB keyboard with RGB lighting.

Hm, we'll have to disagree here then. I tried out the VICE C64 emulator recently, and I found the CRT emulation too accurate! It had all the fuzziness and color bleeding I remember from back in the 1980s. The THEC64, on the other hand, does have an option to add scanlines, but doesn't otherwise make the picture worse. That's my preferred option between simple scaling (with all those big pixels way too visible) and accurate CRT emulation.

Don't forget that the Amiga's native line out is always still there for people who want the real thing!

But as I said before, the current HDMI audio is really good, and the difference between that and the Amiga's native audio, which is slight and I can't really put my finger on it, is probably down to differences in the analog domain. It's just that the HDMI audio level is too low compared to other sources.

That testing method looks very thorough, but is all of that really necessary?

From my obviously imprecise test it looks like the 64-step volume setting is sufficiently linear as it matches the output over HDMI to a degree that there is no audible difference.

It's likely that there are imperfections in the Amiga's DACs, but in my opinion there are two reasons not to worry about that:

1. It's almost certain that such imperfections are different for different individual Amigas, as otherwise there wouldn't be any need to calibrate individual machines for AHI playback.

2. I'd rather have audio output that's slightly better than the original than audio output that is equally imperfect. As far as I know such imperfections have never been exploited to create desired effects. (Probably because they're small and again, different for individual machines.)

After listening to some Amiga audio with headphones I'm not too worried about improving the audio pipeline; most of it is very clearly 8-bit and rather low sampling rate, if not clipping. The big exception is AHI audio, I was surprised how good MP3s sound, even over the Amiga's line outs. But listening to MP3s is not a big usecase for Amigas, even the relatively few that are fast enough.

However, I think it would be good to adjust the HDMI volume to better match other sources. For this you probably don't even need integer math, just shifting everything a few bits to the left should probably do it. 1 bit = 3 dB, right? So that would be shifting by 4 or 5 bits.

Yes, fun is the reason we keep our Amigas around, right?

I connected two different sets of speakers to the Amiga and the monitor line outs, with one set of speakers on the left and the other on the right. I then changed the AmigaAMP volume. The relative volume of the two sets of speakers didn't change, the audio still seemed to come from the middle.

Oh wait, that is of course not a good test, as AHI volume adjustments happen in software.

Same test using Protracker: same result. And with the beep in Prefs also the same result. So it looks like the Paula's volume settings are sufficiently linear.

Then the overall level. I did a few tests playing the same MP3 file to see how some line outs and output through the monitor compare, all measured through my iPhone microphone.

iPod in dock: 75 dB

Amiga line out: 70 dB

Amiga Indivision MK3 HDMI to Dell monitor: 57 dB

Mac Mini DisplayPort to Dell monitor: 74 dB

So looks like the MK3 HDMI audio output can use a boost.

Yes, when A/B testing the most obvious thing is that the audio coming from the Amiga's line out is a good deal louder than the audio coming from the monitor's line out. Perhaps there is enough headroom in the HDMI audio channels to allow for increasing the volume a bit without risking clipping the audio?

It also sounds a little (really just a little) different in a way that's hard to describe, but it's only reasonable that an 28-year-old 8-bit sound system is going to sound a bit different from a modern one.

Everything I tested sounded really good, especially Paul van der Valk's excellent Hybris soundtrack.

I also tested playing back MP3s using AmigaAMP using AHI.

The one thing I had an issue with earlier was playing MOD files in Protracker 3.15 running in a PAL screen and then switching back to a higher resolution screen. I think that was mostly/only an issue at 48 kHz, not or not nearly as much at 96 kHz. This now also works fine. (Tip: when you map different Amiga resolutions, such as PAL and DblPAL, to the same monitor resolution, the screen cycling doesn't trigger an HDMI reconfig so the display and audio don't blank out for a second. And if, like me, you're trying to use Protracker with a USB mouse and the RapidRoad, mouse clicks don't register, you need to click with the regular mouse.)

However, I did encounter something weird when I tried the above. My Workbench was in DblPAL, so I tried switching it to DblNTSC while Protracker was running in the background. Testing the screen resolution was fine, but then activating it brought up a blue screen with some gray horizontal lines at the bottom, with the Indivision reporting a completely different resolution. The audio was garbled. However, I was able to get out of this with Amiga-M, Further cycling through screens didn't return me to the blue screen.

Then it occurred to me that I run Copper-Demon, a utility that uses a custom copper list to create a background color gradient. After quitting Copper-Demon the issue didn't come back, but now I had a garbled mouse pointer after changing the Workbench screen resolution. But the mouse pointer returned to normal after switching screens. (The garbled mouse pointer also appeared on the Amiga's analog output, though.)

However, I couldn't reproduce this after a reboot.

Is audio capability in monitors now detected automatically? I can now use a DVI monitor with audio enabled, I'm pretty sure that didn't work before.

I did have some weirdness after the firmware upgrade, the monitor wouldn't recognize the signal until I tested a different resolution and after that everything was fine but it seems the overscan is different.

I'll try some more audio stuff later, but so far no problems, but then again, I didn't have significant audio issues before, either.

Well, yes, this isn't my first rodeo so I knew I needed to look at the wiki, but I started looking after this page:

http://wiki.icomp.de/wiki/Indivision_AGA_MK3

What is the date for the new versions? On the wiki I only see a link to the 17 sep versions.

Perhaps it would be helpful to make a sticky topic with new firmware announcements?

Well, yes, most especially older games are not going to work with a USB joystick. But are there any games that work with a USB joystick? I tried a small number of workbench-friendly games, but no luck so far. (To be fair, I haven't had any success at all with USB joysticks in any situation except the THEC64 mini/maxi and the joysticks that come with those.)

I guess I need to take my two half-working arcade joysticks and transplant some micro switches to get one that works properly. And figure out how to get WHDLoad to work...

I have a couple of joysticks from way back in the C64 days, which don't work 100% anymore. So I thought I'd try a USB joystick with the RapidRoad. The software recognizes the joystick and I can for instance program a button to perform a display beep with the Poseidon/Trident software, but with some limited testing I couldn't find any games that recognized the joystick.

Anyone having more luck with this?

I use a Synology NAS with smbfs. I get about 200 kB/sec transferring data between my Amigas and the NAS, while with wget to an FTP server 50 km away I get 500 kB/sec with my 68060 A1200 with a PCMCIA Ethernet card and 375 kB/sec with my A3000 and the X-Surf.

However... the sync operation where FolderSync2 checks which files are different takes forever. And I haven't been able to fully automate everything, so that's pretty annoying. I guess I should see if rsync works better.

I guess I'm spoiled by Apple's Time Machine which makes incremental backups every hour. (Although measured as MB/sec, that's also pretty slow compared to the raw throughput the system is capable of.)

Back to HDD vs SSD: one issue I have is that SCSI and IDE HDDs that work with Amigas are no longer mainstream products. So if an old one dies, what then? Replace it with another old one, or find a different solution at that point? That's why I got the Buddha for my A3000, so I no longer depend on SCSI drives or SCSI-based converters.

On the other hand, I found a really cheap IDE-to-SATA adapter so I could use a 160 GB laptop drive in my A1200... The A1200 is a pretty sweet machine in this regard because it can boot from IDE (=CF) and PCMCIA got big in the 2000s so there's still a lot of that stuff around.

The A3000 and earlier Amigas have a hard enough time working with anything even somewhat modern and an even harder time booting off of it. Good thing there's the Gotek floppy emulator.

I'm also surprised to hear you say a mechanical HDD would be better than solid state storage.

In my experience, as long as they're not subjected to too much power and/or heat or mechanical stress, low power integrated circuits (chips) very rarely fail, and certainly not just because of age. While magnetic storage has a ton of things that can and will fail over time: motors, bearings, heads and platters moving past each other very close by at high speeds, the magnetism of the media itself...

Now flash memory is a little different because it can wear out and maybe also deteriorate over time, but in practice with a modern large CF card and the Amiga 1200's IDE speeds there is no way that's going to be a significant problem in practice.

But in any event, it's still important to make backups. One good way to do this is get an IDE-to-CF adapter that holds two CF cards. That way, you can have a bootable backup of your main drive available at all times. Another option is to use an internal CF card connected to the IDE port and boot from that one, and backup to an external CF card in a CF-to-PCMCIA adapter. But then you'll have some work to do if/when the internal card fails because the backup won't be bootable.

If you already have a fileserver such as a NAS, then network backups are a no-brainer. (Although those are slow, even by Amiga standards, in my experience.)

If I were to do more than a tiny bit of programming on an Amiga, I'd look into CVS to keep my source safe.

Here you go.

(By the way: wow, ZIP makes an MP4 file 50% smaller!)

What do you want to see? Just the mouse pointer moving to the right and getting taller?

I can make a video tomorrow.

Hm, maybe that's part of it but it also looks like the horizontal and vertical timing is fairly different with and without VGAOnly.

Would you be interested in discussing setting up custom screenmodes in a separate thread?

One I've been working on is a modification of Euro36 for 540 visible lines (i.e., 1080p / 2) at 25 Hz with no interlace, and then see how much additional horizontal overscan is possible. That would be a good mode for web browsing, where you need a lot of space but really can't afford a 70 ns pixel mode with 256 colors, that's way too slow. However, I just can't figure out the settings to change to get the extra overscan.

Oh wait, there is one thing that makes a difference: I use VGAOnly in DEVS:Monitors, as the VGA monitor I used to use needs it.

Without VGAOnly the overscan is very different and my mouse pointer doubles in height when I get to the right side 16 pixels of the screen. Mystery solved, I guess: use VGAOnly.

SYS:Tools/ShowConfig tells me I have an AA Lisa (id=$00F8).

I got BorderBlank so long ago that I actually forgot it's not part of the system... But recently I started using Copper-Demon which canalso turn on the borderblank feature with the right tooltype.

Copper-Demon's main purpose is showing a nice background color gradient using a custom copper list, but it has an important extra feature: you can set the size of the mouse pointer. This is useful in some screen modes that make the mouse pointer look weird. Doesn't overrule the height issue, though.

As I'm going on and on anyway: FreeWheel lets you set the mouse speed in the X and Y directions independently, which I find useful on SHires-based screenmodes, as well as improve the functionality of the scroll wheel (useful with a USB mouse with RapidRoad).

(Good thing I upgraded to 64 MB fast RAM so my A1200 can hold all these tools in memory.)

One thing that make audio a lot better for me is using 96 kHz rather than 44.1/48/88.2.