openMSX "Accuracy"

By mars2000you

Enlighted (6430)

06-11-2018, 22:52

Concerning blueMSX: some ports that don't depend from libreto/RetroArch exist, especially

* CocoaMSX for MacOS : https://github.com/CocoaMSX/CocoaMSX
* blueMSX-Wii for the Wii console : http://www.wiimsx.com/
* MSX.emu for Android and iOS
* blueMSXBOX for XBox

I will not edit myself this wiki, but I think these precisions should be included. Besides, the fact that MSX.emu is actually a blueMSX port requires to change a little the table.

By TomH

Champion (338)

07-11-2018, 03:53

I'll have a look at it if I can muster the enthusiasm. I find that whole school of listing and ranking things by arbitrary jargon very exasperating.

The whole 'cycle accuracy' thing in particular has probably exhausted my patience for the week. Even just an MSX 1 has at least two separate clocks in it — the 3.58Mhz for the CPU and the 5.37Mhz for the VDP. So whose clock are we talking about? If you've a cycle accurate VDP and a cycle accurate Z80, with properly timed communications between them, are you accurate to whatever is the least common multiple of the two clocks? What about if you're modelling a composite signal like me, which is continuous and analogue? Am I allowed to one-up my competitor by just constantly sampling that at a higher and higher precision?

I am grateful for this opportunity to rant.

By mars2000you

Enlighted (6430)

07-11-2018, 13:36

@TomH: you could be interested by this article written by Daniel Vik, the main coder of blueMSX, about cycle accuracy: http://www.danielvik.com/2010/04/cycle-accurate-computer-emu...

Of course, in fine, it's always a problem of definition, eventually limited by the computer resources. You can indeed have a definition that is closer to the real thing, but will add (almost) nothing visible for the end-user, except that he will need a more powerful machine to run the emulator without problem of resources.

By the way, I had already this kind of discussion in 2009 on the SMS forum: http://www.smspower.org/forums/11817-NewSMSEmulatorRetroCopy... and one of the possible conclusions was already that 'cycle accuracy' was more a marketing expression. So, nothing new under the sun 9 years after!

By Manuel

Ascended (19299)

07-11-2018, 15:20

A similar story from Maarten ter Huurne, one of the openMSX developers: https://www.msx.org/news/en/openmsx-t-dose-conference-talk
The slides: http://www.t-dose.org/2014/talks/inside-emulator
The video: https://www.youtube.com/watch?v=v7VTWEtmfRk

By TomH

Champion (338)

07-11-2018, 15:58

Agreed entirely on "cycle accuracy" as a marketing expression, which is why it's a frustration that what attempts to be an authoritative wiki — and seemingly gets a decent amount of traffic — has decided to endorse it as an informal synonym of "perfect accuracy".

Oh well, c'est la vie.

By Grauw

Ascended (10706)

07-11-2018, 17:12

I think the term cycle accuracy isn’t super precise on what exact level of accuracy there is, but in contrast to line or frame accuracy it gives me useful information...

By TomH

Champion (338)

07-11-2018, 16:55

It definitely gives you exclusive information: it excludes some of the false simplifications the author might have made. But I'm not sure it tells you any more than that, and it's all based on the honour system and subjective analysis anyway as per the linked SMS thread getting into the weeds on whether blueMSX deserves the label.

I'd definitely argue that it's nonsense to consider, as that Wiki does, that "Very high" accuracy is worse than "cycle" accuracy. It's like saying that bananas are better than Tuesdays.

By Bengalack

Paladin (721)

13-03-2020, 09:07

Old thread, I know.

I just want to apologize for, starting this thread - then follow it for a little while - and then going AWOL! At the time I had to suddenly and totally focus on other things, and I had no notifications from this board to notify me about updates msx.org is a bit tricky this way

I also want to thank you all for following up on the main topic! But also on the digress, which I will just touch upon now. Better late than never

Manuel wrote:

ANyway, I also remember Fear of an FM Planet. It was one of the first MSX2 demos I saw and I was very impressed with it. Great to see you again! I think I even met you in Tilburg in 1993 or so, is that possible?

Thanks! Nice hear. But no, it wasn't me in Tilburg.

NYYRIKKI wrote:

I remember very well that I downloaded "Fear of an FM-planet" from Funet some time in 1997 or so and I was quite impressed to learn it was made in Norway. The whole Norway "MSX scene" has been quite a mystery to me ever since. I don't believe MSX2 computers have been sold there and yet there was this kind of stuff coming out in "early days" (pretty much meaning time before Internet was an affordable hobby)... I hope you could light up this mystery to me a bit. How big was the user base? You also probably have some insight information about the copy parties etc. ? Was the MSX2 scene built around home upgraded SVI-738's or did you import some Phillips machines from Netherlands?

Algorythms explained this really well. I can add that I was part of all this, attended meetings and such, but I was just a (young) participant. I had/have no idea of how big the user base or community was. Communication at that time was usually by snailmail from contacts. -Contacts that you had met via meetings, the Swedish computer magazine "Svenska Hemdator Nytt" and the Danish "MSX-Brugerklubben".

I got my first MSX around 1986 or so, a Sony Hit-Bit HP75P. Using this, I started BASIC and assembly, and exchanged code and software with different people in Norway (most which I have lost contact. Frode Hansen - is he around? He wrote his own assembler, I recall), people in Sweden (Mr. QQQQQQ and Mr. Haward of WC-Hakkers and some others), and one in Finland (in a group called SPC).

I initially got a Sony, as there was a small "Sony-fanbase" in my hometown Sandefjord. But after I learnt that one could buy an "old" SVI-738 at very cheap prices and get it built as MSX2 by some quick soldering, I did that. -Or more correctly, Henrik Gilvad, HG, or "Hacker Grog" did that :-) Around 89 or 90 or so.

The cool thing now, is, that I just reconnected with Arne, my partner in crime. Aka Crazy Jack. Going down the memory lane for sure

By FiXato

Scribe (1742)

13-03-2020, 22:23

Bengalack wrote:

I got my first MSX around 1986 or so, a Sony Hit-Bit HP75P. [...] I initially got a Sony, as there was a small "Sony-fanbase" in my hometown Sandefjord.

So, is this perhaps your FINN ad? ;)
(I've been seeing it pop up every few months or so for the past 1 or 2 years. ;) So far it's been the only MSX I've seen pop up since moving from the Netherlands to Bodø in northern Norway.)

Edit: lol, I just noticed I already mentioned that ad here back in October 2018.

By Bengalack

Paladin (721)

14-03-2020, 16:13

He he, no, it's not my ad :-) Not living in Sandefjord anymore, but closer to Oslo.

I could have liked to buy it, but then again, I like MSX2 far more than MSX1. I have my SVI-MSX2 and I'm happy with that.

Slightly related: We have an annual retrogaming-fair here in Norway (in Sandefjord, in fact!), where I usually see msx-rigs on display and where one can meet old msx'ers. That's of course one of the highlights of the year