TG68 - The Open Source Minimig CPU into the FPGA

[HenryCase]

I frequently use URLs that are too long in my posts, but I do know how to easily resize them. If downix or any other forum member is looking for an easy way to resize pictures they find online, check out this method:

1. Copy URL of image (right click->copy image location in Firefox).
2. Go to http://www.shrinkpictures.com/
3. On Resize Images form, click browse. In file open dialog, paste image URL, click on Open button.
4. Select resizing options, then click on Resize button.
5. Once image resized, you will have an option to host image at www.4freeimagehost.com. Click on the link. Use hosted image in forum post.

Here's the link to the resized Altair 8800 image I made:
http://www.4freeimagehost.com/show.php?i=PUSHdfc6b739ddc9.jpg
It has lost some of the cool detailing visible in the full size picture due to its smaller size (25% of original), which is a shame.

Hope that this post is useful.

[Colin_Camper]

Maybe the Altair pic should be left in all it's glory.

Boy! Back in the day I would have loved one of those.  :-)

[MiniMorph]

I would like to order a Altera DE1, but I hate those fees.

The fee would be the same if I order 5 DE1's as if I order 1 so that would save some cash.

Is there 4 more people in the UK or EC that would like a Altera DE1 I will order 5 and sell the other 4 on.

So are there 4 others who want a DE1 ?

[downix]

Ok, pt the resized one up, btw that free image host of yours stinks, useless for posting pictures into sites.  So I put it on one of my own sites.

[ChaosLord]

I am waiting for the DE-A version with a proper Analog VGA port on it.

[HenryCase]

downix wrote:
Ok, pt the resized one up, btw that free image host of yours stinks, useless for posting pictures into sites.  So I put it on one of my own sites.

I've never used that image hosting site before today, I created the guide in a couple of minutes. I'm just glad you resized the picture. :-) :roll:

amigadave wrote:

512 colours (or as we would write over here, colors)?  I don't understand that limit, but most Amiga software only requires 16 or 32 colors and productivity usually will work fine with only 4 colors.

The Amiga OCS displays 16 or 32 colors out of a palette of 4096 colors. HAM mode can use all 4096 colors on a single picture.

That's because the OCS has 4 bits of final digital output on all 3 Red, Green and Blue channels. 3 x 4 =12 total bits to control the color of every individual pixels 2^12=4096.

The aforementioned board has bits numebered 0 to 2 on these 3 channels. 0 to 2 means 3 bits per channel 3x3=9 bits per pixel on the final output. and 2^9=512.

freqmax wrote:
Other factors are ofcourse FPU, and MMU. I know MMU is used by unix operating systems. But for anything else are these things really used in the Amiga enviroment?

Mac emulation...

[TobiFlex]

eslapion wrote:
The aforementioned board has bits numebered 0 to 2 on these 3 channels. 0 to 2 means 3 bits per channel 3x3=9 bits per pixel on the final output. and 2^9=512

Thats not true! That was the color count for the XESS Board.
The DE1-Board use 4 Bits per Color = 3x4=12 bits per pixel and 2^12=4096. The DE1 Board has the same color count as the minimig!
The DE2-Board use 10 Bits per Color = 3x10=30 bits per pixel!
Viele Grüße
TobiFlex

[amigadave]

eslapion wrote:

amigadave wrote:

512 colours (or as we would write over here, colors)?  I don't understand that limit, but most Amiga software only requires 16 or 32 colors and productivity usually will work fine with only 4 colors.

The Amiga OCS displays 16 or 32 colors out of a palette of 4096 colors. HAM mode can use all 4096 colors on a single picture.

That's because the OCS has 4 bits of final digital output on all 3 Red, Green and Blue channels. 3 x 4 =12 total bits to control the color of every individual pixels 2^12=4096.

The aforementioned board has bits numbered 0 to 2 on these 3 channels. 0 to 2 means 3 bits per channel 3x3=9 bits per pixel on the final output. and 2^9=512.

Yes, I know all about how the Amiga OCS uses a palette of 4096 colors and can display them all in Hold And Modify.  What I had not done was the math using only 3 bitplanes to come up with the 512 color limit (I somehow thought it was a different number).  Anyway, I wonder if the XSA-351000 Spartan 3 Proto-Typing board's 512 color palette would work for all other Amiga programs that don't use HAM mode.  I don't know of any games that do (but there are probably a couple).

DCTV only uses 3 bitplanes per color and can output millions of colors to composite output and even has an RGB converter to display all those colors back in RGB mode.  I would love to go down that route and have the capabilities of the DCTV reverse engineered into the Minimig, or to add a DCTV to the XSA-351000 board's expansion port somehow and have an Amiga display of millions of colors natively using only 3 bitplanes and such a low amount of display power it would be very fast.

TobiFlex wrote:
Thats not true! That was the color count for the XESS Board.

My apologies, the "aforementioned" board in question was the Xess XSA-3S1000 and not the DE1.

The DE1 does support more color and the DE2, well, the DE2 is probably what commodore should have come up with after AGA if it hadn't died...

amigadave wrote:
Yes, I know all about how the Amiga OCS uses a palette of 4096 colors and can display them all in Hold And Modify.  What I had not done was the math using only 3 bitplanes to come up with the 512 color limit (I somehow thought it was a different number).  Anyway, I wonder if the XSA-351000 Spartan 3 Proto-Typing board's 512 color palette would work for all other Amiga programs that don't use HAM mode.  I don't know of any games that do (but there are probably a couple).

What could easily be done is to emulate the complete OCS or ECS internally and simply not output the LSB of each color channel. Simply connect bits 3-1 from each color channel of the virtual denise to color channels 2-0 of the VGA port.

What really gets my attention with the Xess board is that it is said to be able to carry up to 1Million gates. The DE2's cyclon II is said to be limited to around 68000 (hey nice number...) logic elements.

How does a "logic element" compare to a "gate". Is that the same thing? Can the Xess product really carry about 12 times more stuff than the Altera?

[Belial6]

@TobiFlex

I would love to help, and think the idea of the DE-1 is great.  Unfortunately, I have no experience with coding for FPGAs.  If I were to get one, is there any kind of testing I could do that would be helpful to you in your debugging.

The system still having bugs does not scare me.  I have been happy with my C-One, and I paid more for that than the price of a DE-1 board.

If there is any testing I could do, and I could get the bitstream (?) files from you, let me know, and I will get a DE-1.

Thanks

[freqmax]

@amigadave:
What do you mean by DCTV ..?

freqmax wrote:
@amigadave:
What do you mean by DCTV ..?

He means this : http://www.amiga-hardware.com/showhardware.cgi?HARDID=282

[MiniMorph]

Is this an Altera DE1 :-
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=544-1736-ND

Looks like it to me !!