Atom GODIL VGA Adapter

emulators, hardware and classic software for atom + system machines
Post Reply
User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 13, 2013 9:00 pm

Continuing from the Atom Colour Board Thread.

http://www.stardot.org.uk/forums/viewto ... 120#p73695

Link to the latest VHDL source code on github:
https://github.com/hoglet67/AtomGodilVideo

Dave
Last edited by hoglet on Wed Nov 13, 2013 10:39 pm, edited 3 times in total.

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 13, 2013 9:01 pm

roland wrote:In the Atom Colour Board threat you mentioned to make a mod to use pin 9 of PL4 so you put all those VGA signals on PL4. Did you ever work this out?
I've not really explored this option any further. You would still need a custom cable, and you might need to sacrifice Orange.
roland wrote:Or ... what hardware is needed to program such a board? I think it's worth a thread to explain what is needed to program a FPGA, which programmer for what device etc. I know the information is on the internet, but if someone on the forum wants to share this information, I can focus on fixing an Atom that might become for sale.
This is what I bought:

The GODIL:

GODIL40_XC3S250E DIL FPGA module (40 pin DIL):
http://shop.trenz-electronic.de/catalog ... cts_id=634
Price 58.31EUR inc VAT

The Programming Cable (needs a Windows XP PC with a Parallel Port):

GOPLCP GOP JTAG adaptor
http://shop.trenz-electronic.de/catalog ... cts_id=135
Price 23.68EUR inc VAT

Postage to the UK was 14.68EUR inc VAT

Grand Total was 96.67EUR

All of the programming software is free (but the downloads are massive).

The cable design is quite old - there is a newer USB Xilinx Platform Cable which might be a better purchase if you can find one.

I'd recommend having the ability to program it yourself, because it's so much fun!

Dave
Last edited by hoglet on Wed Nov 13, 2013 10:39 pm, edited 1 time in total.

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL Video Adapter

Post by roland » Wed Nov 13, 2013 9:33 pm

Hi Dave,

Do I also need this accessoire:
40 pin DIL connector, 2.54 mm = 100 mil standard-pitch, 15.24 mm = 600 mil standard-gap (Trenz Electronic part number: 23498)

The picture on the webpage is not very clear if the module has the pins for the ic socket of the 6847.


What software do I need? I prefer Linux versions if that's available.

Grant total including shipping to the Netherlands is €76.38. So I have to sell my next Atom for €76.38 (I'll include a power supply and a disc pack :) )

Greetings,
Roland
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL Video Adapter

Post by hoglet » Wed Nov 13, 2013 10:01 pm

roland wrote:Do I also need this accessoire:
40 pin DIL connector, 2.54 mm = 100 mil standard-pitch, 15.24 mm = 600 mil standard-gap (Trenz Electronic part number: 23498)

The picture on the webpage is not very clear if the module has the pins for the ic socket of the 6847.
No, you don't need this, as the module comes with the 40 pin DIL connector already soldered on. I think this would be used with the bare modules.
roland wrote:What software do I need? I prefer Linux versions if that's available.
You need Xilinx ISE versions 10.1 and 14.7. Both are available for Windows and Linux but the downloads are massive (3GBish each).

http://www.xilinx.com/support/download/ ... tools.html

The reason you need two versions is that 10.1 is the last one that supported the Parallel Cable III (which is what the GODIL Programmer is).

The latest programming cable is USB, but is really expensive in the UK.
roland wrote:Grant total including shipping to the Netherlands is €76.38. So I have to sell my next Atom for €76.38 (I'll include a power supply and a disc pack :) )
Hmm, this seems a bit too cheap. What are the part numbers in your cart?

Dave

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL Video Adapter

Post by hoglet » Wed Nov 13, 2013 10:31 pm

This is a clone of the latest USB Xilinx Download Cable:
http://www.ebay.co.uk/itm/Xilinx-USB-Ca ... 0939599294

I might order one as a Christmas present to myself.

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Wed Nov 13, 2013 10:44 pm

Here's how to build the parallel cable. But imho it's not worth the trouble of makng it at home if you can buy one for about €25,00: http://startingelectronics.com/projects ... rogrammer/

I'll post my shoping cart tomorrow.
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 13, 2013 10:50 pm

roland wrote:I'll post my shoping cart tomorrow.
This was mine....

Products
------------------------------------------------------
1 x GODIL40_XC3S250E DIL FPGA module (40 pin DIL) (TE0261-00) = 58.31EUR
1 x GOPLCP GOP JTAG adaptor (TE0259-00) = 23.68EUR
------------------------------------------------------
Sub-Total: 81.99EUR
United Parcel Service (XML) (UPS Standard): 14.68EUR
EU TAX 19.0%: 15.43EUR
Total: 96.67EUR

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Thu Nov 14, 2013 7:40 am

And this is mine:

Products (Edit)
1 x GOPLCP GOP JTAG adaptor 19.90EUR
1 x GODIL40_XC3S250E DIL FPGA module (40 pin DIL) 49.00EUR

Sub-Total: 68.90EUR
United Parcel Service (XML) (UPS Standard): 7.48EUR
Total: 76.38EUR
GODIL-shopping-cart.png
Looks like I don't have to pay VAT. I have a company with a VAT-nr, so I think that's why they leave out the VAT. No problem for me as I pay enough taxes already :(

Regards,
Roland
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

Prime
Posts: 2869
Joined: Mon Jun 01, 2009 12:52 am
Contact:

Re: Atom GODIL VGA Adapter

Post by Prime » Thu Nov 14, 2013 9:33 am

Just a quick note to say the Xilinx programming cables also work for the XC95xxXL series CPLDs that I use on the Atom RAMROM & Colourboards.

Cheers.

Phill.

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Fri Nov 15, 2013 10:20 am

Today I ordered my GODIL and cable. Possible shipment date is 19.11.2013 so I expect to receive it next Friday :)
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
oss003
Posts: 3329
Joined: Tue Jul 14, 2009 12:57 pm
Location: Netherlands
Contact:

Re: Atom GODIL VGA Adapter

Post by oss003 » Fri Nov 15, 2013 10:36 am

roland wrote:Today I ordered my GODIL and cable. Possible shipment date is 19.11.2013 so I expect to receive it next Friday :)
Yes, Christmas comes early this year ..... :lol:

Greetings
Kees

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Fri Nov 15, 2013 1:52 pm

Luckily the Dutch Santa Claus, a.k.a. Sinterklaas, arrives tomorrow in Groningen, so he can drop it in my shoe by the end of the week :)

[ For non-Dutch readers: it's a tradition that while this Sinterklaas is in the country, children set one of their shoes in front of the stove. Often with a carrot in it. During the night, Sinterklaas and his servant (or helper) come down the chimney and put small presents in the shoes. Something like the world-wide Santa Claus does with socks ]
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
oss003
Posts: 3329
Joined: Tue Jul 14, 2009 12:57 pm
Location: Netherlands
Contact:

Re: Atom GODIL VGA Adapter

Post by oss003 » Fri Nov 15, 2013 2:54 pm

To be clear ....... the carrot is for the horse of Sinterklaas :wink:

Greetings
Kees

Prime
Posts: 2869
Joined: Mon Jun 01, 2009 12:52 am
Contact:

Re: Atom GODIL VGA Adapter

Post by Prime » Fri Nov 15, 2013 3:26 pm

I remember being at the house of a female friend of mine on Christmas eve, and being asked to take a bite out of the mince pie (for Santa) and the carrot (for Rudolph)..... so that her children would see that Santa had visited.

So sounds pretty similar really.

Cheers.

Phill.

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Fri Nov 15, 2013 7:34 pm

I remember being at the house of a female friend of mine on Christmas eve, and being asked to take a bite out of the mince pie (for Santa) and the carrot (for Rudolph)..... so that her children would see that Santa had visited.
Suppose if they laid out some hay for Rudolph :lol:

And why says the forum software "Your message contains too few characters." above this post. How many characters do I have to type so that message goes away? One sentence more? Still too few characters .... ? Will it ever go away? Help!
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Fri Nov 15, 2013 7:35 pm

Oh ... now the message is gone :?
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
oss003
Posts: 3329
Joined: Tue Jul 14, 2009 12:57 pm
Location: Netherlands
Contact:

Re: Atom GODIL VGA Adapter

Post by oss003 » Fri Nov 15, 2013 7:40 pm

Prime wrote:I remember being at the house of a female friend of mine on Christmas eve, and being asked to take a bite out of the mince pie (for Santa) and the carrot (for Rudolph)..... so that her children would see that Santa had visited.
Hmmmm ... Phill ... I wonder, white beard, red cap, just say 'HoHohohoooo' once for a test .... :lol: :lol:

Greetings
Kees

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Tue Nov 19, 2013 10:59 pm

There is a carrot in my shoe next to the stove ...

Status: exited :D
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 20, 2013 7:18 am

Hi Roland,

Have you started downloading the Xilinx software yet?

It's incredibly big (many GB), and the download speed can be slow.

It took me about 24 hours :shock:

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Wed Nov 20, 2013 8:02 am

Damn, Misty ate the carret :lol:

Hi Dave,

I have started the download of "ISE Foundation - 10.1 Full Product Installation" which will take about 4 hours.... Do I really need v14 as I don't do active development, just programming the GODIL with your code?

Greetings,
Roland
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 20, 2013 8:34 am

roland wrote:I have started the download of "ISE Foundation - 10.1 Full Product Installation" which will take about 4 hours.... Do I really need v14 as I don't do active development, just programming the GODIL with your code?
10.1 should be fine if all you want to do is program.

I'll need to update GitHub with the .bit file (that's what you actually program)

I'll post the set of programming steps, as it's not completely obvious.

I'll also post some pictures of the latest wiring harness that attaches to the test connection. It changed since the last pictures, as I added audio and reduced green to 1 bit.

When is Santa coming?

Dave

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 20, 2013 8:40 am

Oh, one more thing.

Do you have a breadboard and a 5V regulated power supply?

(Like one of these: http://en.wikipedia.org/wiki/Breadboard)

The reason I ask is that I'm not sure what state the GODIL is shipped in (and whether any of the pins start off as outputs). I didn't want to risk putting it into my Atom unprogrammed. So, the first time I programmed it, I put it into a bread board, connected 0v and 5v to the same pins that the 6847 uses, and then programmed it there.

I only did this the very first time, all other times I have programmed it within the Atom.

I suspect this is not really necessary, but I was just being cautious, as I only have one Atom.

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Wed Nov 20, 2013 2:30 pm

Santa has left Eindhoven this morning, so he will arrive somewhere this afternoon:

Eindhoven, Netherlands 20/11/2013 7:24 Import Scan

A colleague of him brought me already some dynamic ram ic's, some eproms and an unknown eprom programmer. It's home made and has no software.

The ISE is already downloaded, now downloading SP3....

I do have a breadboard and a power supply. Although I have three Atoms and a motherboard at the moment, also don't want to destroy one with the GODIL. So thanks for the tip.
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Wed Nov 20, 2013 3:41 pm

Sinterklaas came and dropped a small present for me :D

But don't believe the story about him, walking on roofs with his white horse. He came with a black van (and no black man with him)....

What did he bring to me .... ?
image.jpg
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Wed Nov 20, 2013 7:39 pm

Roland,

I've uploaded a bit file to GitHub that you can download and program.
https://github.com/hoglet67/AtomGodilVi ... er/Top.bit

Here are some notes for using iMPACT to program this into the GODIL:
Create a new directory called AtomGodil and copy the Top.bit file to this directory

Create the PROM File:
=====================

Start iMPACT 10.0

Choose "create a new project" and click OK

Choose "Prepare a PROM file" and click Next

Select 3rd Party SPI PROM
PROM File Name GodilPROM
In Location, browse to the AtomGodil folder
All other values leave as default and click Next

Select Auto Select PROM Density and click Next

Click Finish

In the Add Device popup that appears, click OK.

In the File Browser, browse to the Top.bit and select Open

In the Add Device popup that appers, click No, then Click OK

From the top menu, select Operations/Generate File...

Exit iMPACT, and don't bother saving the project

Program the PROM File into the GODIL:
=====================================

Start iMPACT 10.0

Choose "create a new project" and click OK

Select "Configure Device using Boundary-Scan (JTAG)"

Click Finish

Select Enable Programming of SPI Flash Device Attached to this FPGA

Choose Top.bit and click Open

Select the GODILProm.mcs file and click Open

Select the following SPI Flash Device: M25P16 and click OK

Hilight the Attached Flash device on the left and make sure the Verify and Erase Before Programming check boxes are ticked, then click OK

From the top menu, select Operations/Program...

Programming should take about 40 seconds. Look carefully for any errors.

Exit iMPACT, and don't bother saving the project
Finally, here are a couple more photos you might find useful:

This shows exactly where to put the links:
IMG_0401.JPG
Please make really sure the red and black power supply links are in the right place!

This shows the orientation of the programming cable:
IMG_0415.JPG
And this shows a close up of the wiring harness I made:
IMG_0414.JPG
The connections from left to right are.
Ground
HSync
VSync
Red via a 180 ohm resistor
Red via a 680 ohm resistor
Green
Blue
Audio (filtered using a 3K3 resistor and 4.7nF capacitor)
Not Connected

The orange flying lead on the left is picking up nRST from pin 40 of the 6502.

The orange flying lead on the right is picking up nWRITE from pin 10 of IC40.

Hope I've not missed anything!

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Wed Nov 20, 2013 10:47 pm

Hi Dave,

Thanks for this info. I will definitively need it. About the harnass to the outside world ... I was thinking of using the printer port for it. If I remove the 74LS244 then I can lead the wires from godil to that socket and connect externally a cable with appropriate connectors for audio and video. My only concern is that the quality of the signals doesn't suffer too much with that construction.

I hope to build a cable next weekend...

Greetings,
Roland
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Thu Nov 21, 2013 9:12 am

Roland,

Re-purposing the printer port is an interesting idea and I think it would work well.

I think this weekend I'm going to finally have a go at routing the video signals to PL4 as well.

Pins 3, 6, 7, 8 are directly connected to the 6847 socket, and so can be used for the VGA R, G, B and HS signals.

There are two options I want to try for VS:

a) Use pin 5 (FS) and see how compatible the shorted VS pulse is with existing Atom software.

b) Remove C4 and R6 and add a wire from 6847 pin 28 to PL4 pin 9 and use this for VS.

I could probably make this choice selectable with a jumper on the GODIL.

I also think I can retain the ability to generate Orange by adding one resistor between the Red0 and Red1 outputs on the GODIL.

A small dongle would then be needed to connect PL4 to a 15 Pin HD Dsub socket, that would need to contain 3 resistors to reduce the levels of the R, G and B signals. This should look really neat.

The only concern I have about the above is that the VGA signals would now be passing through level shifters on the GODIL, and this may impact the video quality. There is provision for bypassing the level shifters, but it involve soldering 3 tiny zero-ohm resistors.

There is still then the problem of audio. I was thinking of building a small amplifier that would sit in the Atom case, and would mix together the existing audio and the SID audio, and drive the existing speaker. This would be a tiny PCB that would hang off the GODIL. I was looking to use the LM4861M which will run of 3.3V and will output 0.5W at this voltage.
http://www.ti.com/lit/ds/symlink/lm4861.pdf

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Thu Nov 21, 2013 9:56 am

Hi Dave,

If it's possible, I prefer VS on pin 5 as this involves no modification on the Atom. But the alternative is quite reversible. I'll wait for a moment with routing the video through the printer port as the dongle on PL4 sounds very attractive.

Mixing the audio through an amplifier is also a nice idea. Can these signals just be tight together with a resistor?

Bypassing the level shifters ... does that involve soldering on the GODIL? Scary idea for me :)

And I missed the problem of orange. Orange is a mix of green and red and in de FPGA software is it defined. Why is it missing on the output?

Lots of stuff to keep us busy next month... I think I will use next Sunday for my other Atom problems (fixing BRAN for my ram/rom board and 2 MHz AtoMMC).

Greetings,
Roland
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

User avatar
hoglet
Posts: 9386
Joined: Sat Oct 13, 2012 7:21 pm
Location: Bristol
Contact:

Re: Atom GODIL VGA Adapter

Post by hoglet » Thu Nov 21, 2013 7:51 pm

roland wrote:Mixing the audio through an amplifier is also a nice idea. Can these signals just be tight together with a resistor?
Yes, it's that easy.
roland wrote:Bypassing the level shifters ... does that involve soldering on the GODIL? Scary idea for me :)
Me too. I think we will get away without it.
roland wrote:And I missed the problem of orange. Orange is a mix of green and red and in de FPGA software is it defined. Why is it missing on the output?
Orange is 100% Green and 50% Red. The current design provides two bits worth of Red, which are combined with different resistor values. I think something similar is possible using PL4, but one of those resistors would be connected between jumpers on the GODIL.
roland wrote:Lots of stuff to keep us busy next month... I think I will use next Sunday for my other Atom problems (fixing BRAN for my ram/rom board and 2 MHz AtoMMC).
Fun, isn't it :lol:

Dave

User avatar
roland
Posts: 4004
Joined: Thu Aug 29, 2013 9:29 pm
Location: Born (NL)
Contact:

Re: Atom GODIL VGA Adapter

Post by roland » Thu Nov 21, 2013 8:43 pm

Fun, isn't it :lol:
Indeed, now I remember why and how the Atom kept me busy for more than 20 years. And what did I do in the past 10 years without it???
FPGAtom: 512 KB RAM, Real Time Clock and 64 colours
MAN WOMAN :shock:

Post Reply

Return to “acorn atom and acorn system series”