Question about minimig,VGA, and NTSC

[pontiac89]

Hello all Amiga enthusiasts,
 Sorry if this not appropriate forum for this question, but did not see forum one that looked more appropriate. Anyway, by way of introduction, I will just say that I owned an Amiga 500 back in the late 80s and early 90s. I enjoyed it very much, especially the Falcon F16 Flight Simulation by Spectrum Holobyte. I had to sell the system about 92 to pay the rent.
Have since then been working with Intel/Windows systems.  Just happened to stumble on info about minimig systems that reproduce Amiga chipset in FPGA. Very interested in getting one but have a basic question.   From my reading , I see that minimig has VGA .  I don't really understand how that works in regard wanting to be able to run software designed for NTSC. I read something about NTSC and PAL cores but again, not sure what that has to do with VGA. Could someone please elaborate on this question. Thanks in advance.
                                                  Paul L
P.S. I still have my Falcon disks and a couple other Amiga games and would like to run them if possible. Thanks again.

[Ancalimon]

You either need to create adf's out of those disks using a real Amiga or a Catweasel to read the disks on a PC.

Or you could simply google for the game.

As far as I know, there are two modes of Minimig the VGA mode and the standard 15khz mode. Correct me if I'm mistaken.

[Matt_H]

Minimig uses a VGA port to be able to connect standard modern monitors. As FaLLeNOnE says, you can set it to either use a 15KHz mode (in which it functions just like the Amiga's 23-pin video port, except in a 15-pin form factor; you'll need a rare 15KHz-capable VGA monitor to use this setting) or 31KHz mode (which functions like a scandoubler plugged into the Amiga's 23-pin port; most modern monitors will work with this setting).

To use Amiga PAL modes, your monitor needs to be capable of displaying 50Hz signals. Many LCD screens these days don't go below 56Hz, so check the specifications before you buy.

[Darrin]

Minimig uses a VGA port to be able to connect standard modern monitors. As FaLLeNOnE says, you can set it to either use a 15KHz mode (in which it functions just like the Amiga's 23-pin video port, except in a 15-pin form factor; you'll need a rare 15KHz-capable VGA monitor to use this setting) or 31KHz mode (which functions like a scandoubler plugged into the Amiga's 23-pin port; most modern monitors will work with this setting).

To use Amiga PAL modes, your monitor needs to be capable of displaying 50Hz signals. Many LCD screens these days don't go below 56Hz, so check the specifications before you buy.

As Matt says.  I just leave my Minimig in 31KHz mode and all CRTs I've tried have worked fine.  As I prefer PAL modes, I always make sure I buy LCD monitors that support 50Hz.  Any LCD will display NTSC 60Hz screens.

If you buy a Minimig then try and get the 4MB RAM version as that will give you 2MB Chip and 1.5MB FAST (or 1MB Chip 2.5MB Fast depending on how you configure it in the menu).  Alternatievly you could also look at the FPGA Arcade if you want AGA or also the Chameleon64 if ECS is fine.

[bloodline]

@Darrin

PAL is 50Hz, NTSC is 60hz

[Darrin]

@Darrin

PAL is 50Hz, NTSC is 60hz

Doh. sorry, flip-flopped the numbers... fixed.

[pontiac89]

Thanks to all who replied to my question. I feel better about the chances of the minimig board being able to provide a NTSC signal via the VGA output. I would like to ask a follow up question and hope at least one of you will go the extra step to answer it.
I am now just trying to picture how the selection between NTSC and PAL is done. I am wondering if I would need to desolder a crytal set for PAL timing and solder one set for NTSC. Also I am trying to figure out about cores. Are cores just another name for a kernal like in Linux ?
I have tried to find these answers by just surfing various forums and such but am still a bit hazy on what needs to be done to get a board ordered from someone like AmigaKit up and running. Thanks again and I appreciate your time and consideration

[Matt_H]

Note that if you're getting output from the VGA port in 31KHz mode it won't be a "true" NTSC signal in that it won't work with professional NTSC video equipment. But Amiga NTSC software will work fine. As will PAL. Amigas can switch between PAL and NTSC in software, and I think the Minimig has its own setting to change the default. Not sure though.

An FPGA core is essentially the firmware, except it's loaded in at each power-on, rather than stored in Flash or ROM. An Amiga core will make the device an Amiga. A C64 core will make the device a C64. It's more low-level than a kernal, since a core is a full hardware emulation rather than OS software code.

[pontiac89]

Again thanks to Matt_H, Darrin, bloodine, and FaLLeNOnE for your responses. Your responses have been very helpful. I am determined to get a minimig system ( with 4 MB). I know that it is not for sure that it will be able to run all the software I still have from 80s/90s although I did see that there is at least one config that will run Falcon F16. It may be a month or 2 before I can get one, but when I do I will check back in with news. Thanks again and any additional advice regarding configuration info ( just a link or anything) will be appreciated.
Paul L

[mikej]

It should be noted that the FPGAArcade board has a clock synthesis chip which can produce the exact base PAL / NTSC frequencies needed - if I remember correctly they are slightly different ...

/MikeJ

[Darrin]

Again thanks to Matt_H, Darrin, bloodine, and FaLLeNOnE for your responses. Your responses have been very helpful. I am determined to get a minimig system ( with 4 MB). I know that it is not for sure that it will be able to run all the software I still have from 80s/90s although I did see that there is at least one config that will run Falcon F16. It may be a month or 2 before I can get one, but when I do I will check back in with news. Thanks again and any additional advice regarding configuration info ( just a link or anything) will be appreciated.
Paul L

I just had a look to see if I had F16 as an ADF to test for you, but I don't (I have the original disks somewhere).  I'll see if I can track it down and try it (there shouldn't be any problems with it).  I'll run it on both the Minimig and FPGA Arcade and let you know the difference.  10A Tank Killer runs on both and runs like a whippet on the FPGA Arcade with all of the graphic settings on maximum.

Edit:  Just tried the WHDLoad versions of F16 Combat Pilot on both machines and they both fail with the error "Illegal Instruction ($E010) at $7D5E occured".  I'll let you know what happens with the ADF images when I find them and I'll fiddle with WHDLoad too.

(F19 Stealth Fighter runs fine from WHDLoad)

[Dwyloc]

Edit:  Just tried the WHDLoad versions of F16 Combat Pilot on both machines and they both fail with the error "Illegal Instruction ($E010) at $7D5E occured".  I'll let you know what happens with the ADF images when I find them and I'll fiddle with WHDLoad too.

(F19 Stealth Fighter runs fine from WHDLoad)

Just to let you know the adf version is available for legal download at http://www.back2roots.org/Games/ADF-Games/F/ and would seem to work with out problems on my 2MB Minimig from my quick few minutes of testing.

[Darrin]

Just to let you know the adf version is available for legal download at http://www.back2roots.org/Games/ADF-Games/F/ and would seem to work with out problems on my 2MB Minimig from my quick few minutes of testing.

Cheers.  I've tried it on my Minimig v1.1 and it works fine, however I couldn't get it to work on the FPGA Arcade with either the 68000 or 68020 and with AGA or ECS.  I might need to fiddle with the various settings or wait until Mike releases that updated core.

[pontiac89]

Many thanks to mikej, Darrin, and Dwyloc for your interest and efforts concerning the feasability of being able to run the software I mentioned. The system I have in mind is the minimig v1.1 so that is promising that you ( Darrin ) were able to get the ADF image file to run ( which I suspect would mean that it is also feasible that the original disks would run)
 In any event, my determination to get back into Amiga systems is not wholly motivated by being to run any one particular progam. I am also just interested by the FPGA aspect of this scene. In fact, i recently purchased an Altera Cyclone2 DE1 Development board and registered to use the web version of that CAD software used to program the board. I have tinkered with it just a bit so far , but am very interested by the possibilities. Of course,  I know you guys and/or gals all realize that the minimig and NatAmi are realizations of these possibilities.
 So anyway thanks again and I will be posting again ( maybe in the forum having to do with hardware/software as well as this one) Thanks again.
                                                                              Paul L

[Darrin]

Many thanks to mikej, Darrin, and Dwyloc for your interest and efforts concerning the feasability of being able to run the software I mentioned. The system I have in mind is the minimig v1.1 so that is promising that you ( Darrin ) were able to get the ADF image file to run ( which I suspect would mean that it is also feasible that the original disks would run)
 In any event, my determination to get back into Amiga systems is not wholly motivated by being to run any one particular progam. I am also just interested by the FPGA aspect of this scene. In fact, i recently purchased an Altera Cyclone2 DE1 Development board and registered to use the web version of that CAD software used to program the board. I have tinkered with it just a bit so far , but am very interested by the possibilities. Of course,  I know you guys and/or gals all realize that the minimig and NatAmi are realizations of these possibilities.
 So anyway thanks again and I will be posting again ( maybe in the forum having to do with hardware/software as well as this one) Thanks again.
                                                                              Paul L

You're welcome Paul.  Glad to be of help.

Also, check out http://www.minimig.net for other FPGA users.