Posts by mega65

Hello,

This is quite weird. Please email an example of a SID file and player you are trying to use that play fine on a real C64, but are not running on your N4DDR board. I'll try them on my MEGA65 here, and let you know the result.

In the very latest bitstreams on the feature branch I am working on, there are 4 sids at $D400, $D420, $D440 and $D460. They are repeated after that to $D4FF, and then repeated in swapped left-right order at $D500, to try to help some old dual-SID programmes to work -- although they tend to be a dogs breakfast.

For this reason, we actually added support for simple playing of SID files to the m65 utility, which fixes the addresses of SID files it loads. But also expect that we will add more SIDs if we have space in the FPGA at the end, possibly 8 or 16 in the end, so software written for the MEGA65 should behave and use only the primary images of the SIDs at $D400-$D47F.

LG

Paul.

Etwa 4MB der 32MBs des Flash wird per Core benutzt. Aber beim DevKit mindestens, benutzen wir einen größeren FPGA der etwa 9MB pro Bitstream benutzen kann.

LG

Paul

Nein, DMA geht bei jedem CPU Takt. Der einzige Ausnahme ist, dass man muss bei 40MHz sein, den Audio DMA zu benutzen. Aber beim Laufwerk und SD Karte, DMA geht immer, obwohl wie langsam der CPU läuft.

LG

Paul.

The FPGA on the Nexys Video board has a big enough FPGA that it could run a MEGA65 bitstream if it was implemented.

LG

Paul.

Ok. I'll just make it possible to trigger the freezer.

Paul.

Hello,

1. This can only be read from within the hypervisor in $D67D bit 4. There is currently no hypervisor trap to allow reading of this.

2. Yes, by triggering the freezer to start. Or rather, I should say that this SHOULD be done. At the moment there is no way to trigger it, but I'll implement it.

https://github.com/MEGA65/mega65-core/issues/245

2b. Would you like to also be able to trigger the matrix mode display instead of just freezing? Also easy enough to implement.

2c. We need an appendix in the MEGA65 book that documents all the hypervisor traps and function calls.

Paul

äh gotcha. Nein, ich glaube, dass momentan niemandem daran arbeitet. Wäre natürlich hilfreich. Braucht nur den Emulator zu schaffen. Möchtest du daran arbeiten? Auch bewusst sein, dass es wird höchstwahrscheinlich für jede Fassung des C65 ROMs unterschiedlich sein.

LG

Paul.

Meinst du, die Register Adressen des VIC-IV Funktions oder was anders? Viel Infos bei https://github.com/mega65/mega65-user-guide

LG

Paul.

Just confirmed: It's a typo: It should read Oct 2020. Has no bearing on whether DevKits are sold out or not. At last check, it was 98 sold, 2 remaining.

LG

Paul.

I have no idea, unless that is an indication that the DevKits are sold out.

LG

Paul

High technoloy export contols, you think? The MEGA65 is too dangerous to impot into the USA?

LG

Paul.

I'm just fixing the documentation in the MEGA65 user guide material now.

There is also 45 pages of "introduction to BASIC" which is coming along nicely now.

LG

Paul.

Quote from wins4

Can you publish an statistics how many DevKits have been sold in which countries?

I don't know yet. All I know is that 6 are from Australia. I'd estimate at least 60 are from Europe, and the rest I simply don't know. USA looks to be a bit underrepresented. Reasons are a bit unclear for that. Some folks from the USA I think got a bit confused by Trenz payment system, but I'm not rerally sure of the truth.

LG
Paul.

Quote from syshack

Thank you Paul, for this extensive explanation on crazy Aussie timezones which doesn't really give me comfort that I moved to downunder for a good reason

With the EU killing daylight saving time, I wonder if OZ will follow. I am sure Queenlanders would agree

BTT: I wonder if you will have the final product shipping only from Germany or will you have an Aussie depot as well?

Well, I don't think that SA will ditch summer time, unless we simply moved to eastern time year round, perhaps. After all, the curtains have already faded and cows put off the milk, so there's nothing to recovere

Now, as for an Aussie depot, this might end up happen. It's certainly happening informally for the DevKits, with most of the units coming to me, so only one lot of customs charges and cheaper freight. But at the scale of sales of the final machines, that might be a bit more complex. Also acting as an importer for a final product is a bit trickier with potential consumer law liability as bringing in kits.

LG
Paul.

Quote from syshack

Quote from adtbm

Hmmm, is Paul already/still awake, what's the time in Adelaide now, or the US east/west coast, etc....

i.e. my prefered chatting times with Paul are around 3 - 4:00 o'clock in the morning

Adelaide has some weird time shift of half an hour to the full hours somewhere else.
While currently in Sydney we have CEST + 8h to AEST, Adelaide is CEST +7.5h (ACST)
https://lmgtfy.com/?q=6%3A57+CEST+to+ACST

We like to say in Adelaide that we are 23.5 hours ahead of Sydney

(They like to say that they are 30 minutes and 20 years ahead of Adelaide, but we know they are wrong
Also if you want real time-zone pain, we have Central-Western Border Time, which is about 200 people on the border of two states in the middle of the desert. They use the average of the two timezones to give +8.45 hour. But until recently, only one half of them followed summer time, so withing this little area you had +8.45 and +9.45. So parts of Australia would be on:

+8 (WA doesn't do summer time),
+8.45 (CWBT without summer time, for the part in WA),
+9.30 (NT doesn't do summer time)
+9.45 (CWBT with summer time),
+10.00 (QLD doesn't do summer time),
+10.30 (SA, where I live, which is west of QLD, but does do summer time), and
+11.00 (Sydney etc that do summer time)

You can also cross most of those by going only north-south, and avoid timezone changes when going east west by picking your route carefully:

If you start in, say, Melbourne and then drive to Brisbane in summer you go back 1 hour as you cross north into QLD. Then drive to the western side of QLD and drive south back into NSW to go forward 1 hour, then keep driving south to Broken Hill (still in NSW) which operates on SA time, so go back 30 minutes. Now drive west into SA to Coober Pedy. Follow the highway north into NT to go back 1 hour (no summer time), now drive back south into SA and head to the western border towns to go back 1 hour and 45 minutes, then drive west into WA staying on border time, now drive north into the desert to go back 45 minutes. Finally drive west to Perth, without changing any time zone. You have no gone through every mainland state and territory changing timezones ONLY when you go north/south, and never when you go east west.

Now, back to the more serious matters:

International freight and import duties suck. I know, because I live in Australia where just about everything travels 15,000km and gets stuck in customs for a month while they slap silly fees on top of the taxes. So we know the problem the folks in the USA are facing, multiplied by a big factor, as freight between EU and USA is fast and cheap compared with getting stuff down here. For Australia, we have formed a little syndicate of those ordering a MEGA65 DevKit, so that we can bulk ship them to save a bit. If folks from the USA want to do the same, we can talk to Trenz about this, but you need to find a trusted party to handle the shipment and deal with customs. For Australia that was easy, because I'm here, and the five or six Aussies who are ordering a DevKit trust me (I already knew half of them, anyway, because our scene is smaller due to smaller population). For the USA this would be trickier, but not impossible. But its not something I have the bandwidth to organise.

So in summary, we recognise that its not ideal, and are open to suggestions how we can help folks -- so lonog as it doesn't burden us or Trenz in the process.

Paul.

Quote from Snoopy

Just a question, because I read it in the description site at Trenz:

Quote

This DevKit is a limited developer’s production run (100 pieces. Orders > 100 will be placed on a waiting list).

Will there be a second batch for the devkits (> 100) or are the orders on the waiting list for the final Mega65 then?

I believe they will go on the waiting list for the production machines. We don't currently anticipate needing to have a larger devkit cohort than the 100 units already offered.

LG

Paul.

The HypeRAM is slow ram in the MEGA65 because of the MEGA65 architecture. The HyperRAM can easily serve 7Mwords per second, and in fact in most cases much faster. We already have demonstrated 10MB/sec with slow ram on the MEGA65 -- its slow compared with the 40.5MB/sec of the MEGA65's fast ram, not compared with Amiga fast RAM.

(And yes, I know the DOS PC emulation was tongue in cheek, but it should be totally possible)

LG

Paul

Also one of the things that has me really excited, is that a few of the very active and productive retro games and tools developers have bought one, each with the definite goal in mind of making releases on the MEGA65! We may yet get Christmas surprises that none of us had previously expected!

LG

Paul.

Quote from Freddy

Quote from adtbm

That was exactly the plan to have enough room for all possible cores and extensions....

If there's enough room, it would be funny to make a PC-XT Core and have a running MS-DOS in a Window inside MEGA-Geos

As absurd as it sounds, it would almost certainly be possible.

Quote from FeralChild

IMHO with such a distribution there is a high chance we will soon see the dev kits on eBay for 2500 EUR each, while many developers won't be able to get one. I was really lucky, just a few days ago I was on vacation without even internet access... not being able to purchase one would be really discouraging.

Yes, I know, Nexys, XEMU, etc.- but they are just not enough. I'm glad the XEMU exists, it allowed me to test:

- most of my 65CE02-specific optimizations
- ROM banking support

but I've got more things to test:

- does my support for C65 keyboard actually work? I've written the code, but it is almost completely untested
- is my C65 keyboard scanner compatible with games trying to read joysticks? my initial C64 keyboard scanner wasn't
- does my IEC support code actually work on Mega65? I've used delay loops in several places, and Mega65 CPU has slightly different timing... I know the documentation about CPU timing is being written now (I will certainly look there), but it still needs testing, especially the JiffyDOS support - it's timing is rather narrow
- can I change the JiffyDOS transfer routine to just disable the badline emulation - and do not waste time for tricky VIC-II synchronization?
- tape reading... same as above, can I disable badlines instead of blanking the display (most 8-bit machines, including VIC 20, does not blank the display)?

AFAIK neither XEMU nor Nexys won't let me test anything from this list - dev kit will allow me to test everything but tape support.

Display More

And for these sorts of situations, if we have developers who are unable to get a DevKit machine for whatever reason, and they are making serious contibutions, then we will find some kind of solution, as we mentioned in the pre-order FAQ.

But aside from that, some answers to some of you questions:

For the badline stuff, yes, I'd just turn the badline emulation off while jiffyloading or accessing tape. No need to blank the display, as you don't have to worry about badlines.

Also for testing tape, if you made up an adapter for the level conversions and power supply to run the tape drive, we could cook up a bitsteam that would allow this on a PMOD on the Nexys board.

Paul.