DFB1X bare bones build

[dml]

Preparing to build one of these (DFB1X) with an untested board minus the CPU & socket.

Before I do, is there a list of known gotchas/mods that might need attention before I start? Have swept the board with a microscope and it looks great but if there are any flaws known after production it would be good to know now and not after I power it up :p

Otherwise I'll get started on it.

[exxos]

All information is here.
https://exxosforum.co.uk/atari/last/DFB1X/index.htm

[dml]

All information is here.
https://exxosforum.co.uk/atari/last/DFB1X/index.htm

Got it, thanks.

[dml]

So this morning I soldered the PGA socket and fitted the 030 IC.

Tested the Falcon with the DFB1X fitted in 'disable' mode. No flames etc. Getting a desktop. So far so good.

Have looked through the link above (The LasST upgrade DFB1X) and while there is plenty of reference on the jumpers/pins/tips and some Q&A etc, I don't see exactly what I'm looking for.

[edit] (not entirely true - there is a bit on setting up a bare board, at least the jumpers part and a few other bits. so that's helpful but it seems the FW flashing part is out of scope)

What I need now is instructions/guide on flashing and setting up a bare-bones board.


To be clear - I have one of the Exxos bare-bones boards - populated but without the CPU socket. I believe the board is completely unflashed but it is not very clear if that just means the TOS image is unflashed or the CPLD is unflashed. If the CPLD is already flashed I'll be happy to skip that step!

Presumably the CPLD is unflashed and I'll need to do that myself. I do have access to a Xilinx DLC9G platform programmer.

I see Dave has some videos on building different revs of the board and I noticed a mention that the Xilinx programming pinout may have changed over time.... things like that make me want to be doubly sure I'm doing the correct steps with the correctly configured cable/pinout, and in the correct order.


I have the DFB1X flash tool, the 404 tos image.

...any pointers on where to look next?

[dml]

Another, more specific question...

Can anyone recommend freely available software compatible the Xilinx programmer and which can be used to flash the DFB1X?

I know there's the Impact suite from AMD and the latest version apparently works from Windows 10... but I can still use XP if necessary. There's apparently a web version of Xilinx ISE (?) but not clear if that's any use for this task.

Something that works with the clone devices would be fine I think.

[edit]

Looks like it might be possible from an RPI so I might look into that - unless someone knows that route isn't going to be feasible for this CPLD?

[dml]

Having read through the Exxos Q&A it seems like the board *might* be CPLD-flashed already. Difficult to tell for sure but it has the 1.04 sticker on the bottom and it shows the following behaviour:

- machine boots normally in 'disabled' mode (as noted earlier)
- allows me to flash a TOS4.04 image to bank 1, apparently without errors
- when 'enabled'...
--- powering the machine on blinks the white LED followed by the red LED which remains on (seems correct?)
--- no video output - VGA shows frequency out of range
--- no other signs of activity (disk access etc.)

Have tried running it with the mainboard FPU & ROM removed, no difference.

Will poke at it a bit more and maybe try another machine meantime. If any of the above is a sign of being pre-flashed, please let me know.

[DoG]

Well if you bought this it says right there in the info text that it has no os or firmware flashed.

[dml]

Well if you bought this it says right there in the info text that it has no os or firmware flashed.

Yep - that is why I assumed it would need a FW flash to begin with. However I later saw this:

Q) Do the barebones have firmware flashed?
A) Yes and no. While I have flashed firmware on some barebones boards, I cannot guarantee it is flashed and class them as not flashed. Flashed boards will have a exxos sticker on the bottom with the version flashed which is 104 at the time of typing.

This board does have the 1.04 sticker. ...which leaves me unsure of what's on there.

I'm still prepared to go the flashing route but this could potentially save a step.

[dml]

An immense amount of trial-and-error later, managed to deduce that:

- the DFB1X board is OK
- my soldering is OK
- the CPLD appears to be pre-flashed (thanks exxos!)
- flashing TOS was successful
- the CPU seems to be faulty, or at least refuses to boot at either 40 or 50MHz. It is now booting to the desktop with a second CPU at 50MHz.

Removing PGAs is not something I like doing more than necessary but this time it was necessary.

It doesn't *always* boot successfully - sometimes just a white screen, sometimes white screen with garbage in the first scanline... looks like an Atari logo blitter conflict to me.

When it fails to boot (white screen) the green LED (D3) is on continuously. When it boots successfully, the green LED just blinks briefly.

While this is not a perfect result, it is a lot better than 10 potentially different unknown things causing a black screen so I'm calling that a win for today.

[Steve]

Hey dml,

Just some of the most important things to check:

Your Falcon PSU MUST output 5.00V minimum (5.10v - 5.20v is better) otherwise a lot of 030 CPUs will typically become unstable and crash after about 10minutes. The measurement should be done on the power output headers (J4) on the DFB1X.

Your motherboard ROM and FPU need to be removed.