exxos's Atari, Amiga & retro forum

Sety, out of curiosity where in the world are you located? Do you have the expertise to solder on ic3? Is this something you need the liquid solder and an oven for?

I'm in Australia.

I was planning on using solder paste and flux (both available locally) and with a hot air torch. It shouldn't be too difficult. It's quite satisfying actually, when the grey solder paste hits transition point and goes all shiny and seems to "suck" the component in to place. :)

terriblefire wrote: 17 Nov 2018 16:19 The sockets I used were the 121 pin BERG sockets.

Hi TF. I have a TF520 close to completion. Still waiting on a few parts. I'll send a photo once I get some flux cleaner, I'm a little too embarrassed right now as my board looks very messy. :)

Could you please tell me the values of C3 and C4?

Any tips for soldering the PGA socket? Is paste and rework torch okay or should I stop being lazy solder each pin with an iron? The sockets were expensive so I don't want to mess that part up. :)

Cheers,
Stuart

I don’t know. I don’t support the 520 anymore and I lost all the files in a hard disk failure. There isn’t a magic number that will or won’t work. They’re all between 1 and 22uF

sety wrote: 10 Dec 2018 08:28
Any tips for soldering the PGA socket? Is paste and rework torch okay or should I stop being lazy solder each pin with an iron? The sockets were expensive so I don't want to mess that part up. :)

Although I haven't built a TF accelerator, I did build a PAK-68/20, which also used a 68020 and the same sort of socket you're describing I think.

You can see it here: https://www.exxosforum.co.uk/forum/viewt ... t=40#p4807.

I manually soldered each and every pin of that socket, and it was quite tough due to the tight pitch of the pins, so if you have got a way of making it easier, then that might be a good way to go.

Only problem I can see with a rework torch is maybe overheating things. I guess if you're experienced with the torch (I'm still learning!) though, you won't have any issues.

sety wrote: 10 Dec 2018 08:28
Could you please tell me the values of C3 and C4?
..
Cheers,
Stuart

TF520 boots even without these caps @32Mhz, however i placed 10uF/25v smd's and these are working perfectly

Yes!!
Okay it doesn't look like much, but I hear key clicks when I press keys, so 68020 is alive. :)

No disk access yet and it crashes (reboots) at the timeout where TOS starts GEM from ROM because of no disk...

Programming the CPLD was a nightmare. Won't program in Impact GUI but will program in CLI batch mode.

The other weirdness is that it only works if GND and VREF are plugged into the programmer. I measured the impedance and it was 10K, but placing a 10K resistor instead didn't work, so I have NFI right now. =/

sety wrote: 16 Dec 2018 11:43 The other weirdness is that it only works if GND and VREF are plugged into the programmer. I measured the impedance and it was 10K, but placing a 10K resistor instead didn't work, so I have NFI right now. =/

If i understand you correct you are expecting the programmer to power the CPLD while its being programmed? if so this is not correct. The board needs to be on and a 3.3v voltage present for anything to program. The programmer does not power the board.

What impedance are you measuring? VREF to ground?

EDIT: By far the easiest way to program these with a Xilinx programmer is to plug the board in.. wire up all 6 wires to the programmer, turn on the amiga and use Impact to program. then reset.

VREF is used by the programmer to check the board is (a) on and (b) so it uses the correct voltage to program a chip. (i.e. so it doesnt cook a chip with too high a voltage).

My bad. I was trying to run it with TOS 1.04

Here it is with EmuTos. It's looking a bit healthier. I rekon it's going to work :)

YES!!!!

:bravo: