Minimig PCB run - interest thread

[jonssonj]

I'm also interested in a minimig in any shape. Fully assembled though if the price is right.

BR
Jörgen

[billt]

Would it be possible to add more than one CPU on future revisions?
What about an DSP, like on the Delphina cards?

The neat thing with FPGAs is that you can do just about anything you want, so long as there is enough room in them for your logic design and enough pins to interact with the outside world. You'd need to add some control logic to the FPGA allowing it the capability to arbitrate and talk to the DSP properly, and assign some FPGA pins to wire up to the DSP on the PCB. Perhaps some of that could be shared with the 68000 bus, perhaps not. It sounds like there's cocnern that the largest pincount QFP style package which is easier to work with does not have enough pins for an IDE port and other things in addition to Dennis's design features. Larger pincount versions of the FPGA exist, as do larger logic capacity FPGAs. Unfortunately the larger pincounts come in BGA, which is much harder to work with, and it's expensive to send out for assembly by a proffessional company. And larger logic capacity FPGAs are just freakin expensive chips. You of course could look for some balance in there, but you'd at least need more pins and thus BGA version to add much more control signals or address/data bussing, even if the additional logic design fits into the same FPGA.

[yadaysw]

I would like 2 PCB with parts in kit, unsoldered.

[ferrellsl]

I would like 2 pre-assembled and tested.

[odin]

freqmax wrote:
Any tip on a better site than rapdishare.com is appriciated. I  find them a bit messy. But just took what I knew at the spot when I was tired.

imagebay.com works for me.

[HyAmi]

I'd like to have at least one assembled and maybe a kit.

[denli]

Put me down for two Minimig v1.0 please.
One fully assembled and one only with SMB.

I'd like it in a mini-ITX or nano-ITX *compatible* form. So if the current 12x12 cm design could just be fitted with wholes in the correct places I would be happy.

[ravnen]

Count me in for a kit. Ports on ribboncable sounds good

[piramania]

I'd like to have at least one assembled one. No soldering for me, please...

[Troels_E]

I would like one Minimig, assembled please.

And as small as possible, doesn't matter if it fits a standard tower as I would do a custom one anyway.

What sreenmodes are supported?

[amigadave]

Troels_E wrote:
I would like one Minimig, assembled please.

And as small as possible, doesn't matter if it fits a standard tower as I would do a custom one anyway.

What sreenmodes are supported?

Dennis' design has a jumper to switch from 15kHz to 31kHz RGB output so it will work on both old Amiga monitors like the 1080 and 1084, or will work on newer VGA monitors.  I think the timing is PAL only at this point, but hope that will change to allow NTSC output from some boards, or switchable back and forth between PAL and NTSC.  The software mimics an OCS A500, so display resolutions should be in the same range as an original PAL A500 (since I am in an NTSC display country I can't remember the exact numbers for PAL displays at the moment).

It is great that Dennis built in a scan doubler so modern monitors can be used.  Some members are asking for composite output so TVs can also be used.

[Ilwrath]

After thinking about it for a bit, I'd take a Minimig kit.  Sign me as interested.

The NTSC timings would be a huge benefit to me, though having it be switchable would be even better.

[mrmkl]

Is it possible to generate both pal and ntsc timings using the same crystal? By using the clock management circuits on the spartan fpga.

I'm interested in at least one PCB.

[FrenchShark]

It could be possible with a 27 MHz XTAL.

See the page:

http://www.opencircuits.com/Minimig_NTSC

Here is the computation:

27,000,000 / 429 x 455 = 28,636,363 (NTSC clock, 0 ppm)
27,000,000 / 432 x 454 = 28,375,000 (PAL clock, 6 ppm)

The DCM from the Spartan 3 accepts only coefficients from 1 to 32 :-(.

The Cyclone III accepts coefficients from 1 to 512.

The NTSC clock generation can be simplified to:
27,000,000 / 33 * 35 -> would fit into 2 cascaded DCMs.

We are less lucky with the PAL clock generation:
27,000,000 / 216 * 227 -> 227 is a prime number !

[Fixer]

amigadave wrote:
It is great that Dennis built in a scan doubler so modern monitors can be used.  Some members are asking for composite output so TVs can also be used.

Talking about that (and I don't mean to sound ungrateful) I would have thought Composite/S-Video would have been a necessity on this thing, considering how console-esque it is.

Anyone know how easy this would be to integrate.. or even standard Amiga-RGB for us Scart users?

[freqmax]

FrenchShark wrote:
It could be possible with a 27 MHz XTAL.
See the page:
http://www.opencircuits.com/Minimig_NTSC
Here is the computation:

27,000,000 / 429 x 455 = 28,636,363 (NTSC clock, 0 ppm)
27,000,000 / 432 x 454 = 28,375,000 (PAL clock, 6 ppm)

The DCM from the Spartan 3 accepts only coefficients from 1 to 32 :-(.
The Cyclone III accepts coefficients from 1 to 512.

The NTSC clock generation can be simplified to:
27,000,000 / 33 * 35 -> would fit into 2 cascaded DCMs.
We are less lucky with the PAL clock generation:
27,000,000 / 216 * 227 -> 227 is a prime number !

Could you explain your equations a little bit more?
27/4.433619 = 6.0898331 ie divide by 6 ..?