exxos's Atari, Amiga & retro forum

Today I'm left alone for the day, so I could setup my workbench and and work a little during lunchbreak.


Today's progress : Socketing the 3 remaining IO ports (#1, #2 and #4), bridging JP14 (under the 3.3V IO Port #2), and installing IC22 (the reset IC). For the latter, the most difficult part was to identify pin 1, because I expected a marking on the package, until I noticed the one pin that was very different from the other.

Last weekend, I installed some of the pin headers


...and I will have to remove the normal pin headers I put on CN8 :evil: to put a header like I will install on other power connectors... but later, when I will have ordered and received said connectors.

A little bit of time tonight, and I had unfolded my big table, and family all asleep, so I finished all the jumpers I need, as well as solder joints 1 (keyboard click) and 2 (DE).


you can see my checklist of what I needed on the pink note :

• JP1 (dual TOS select), bridged
• JP2 (buffer blank), 1-2 bridged
• JP5 (Glue sound), bridged
• JP9 (Glue Hsync), bridged
• JP13 (Rom decoding TOS 1.04), bridged
• JP15 and JP16 (No Blitter), bridged
• JP20 (drive activity LED of the keyboard), bridged
• JP21 (DAC blank), 2-3 bridged

(JP14 is bridged with a bodge wire underneath)

Next time I will install some of the CMS component : the 16Mhz oscillatoir, the falcon DAC, the battery holder. Then I will have to start extracting component from the donor machine.

Today I could arrange a longer session than usual, so I could work on those parts


The CMS parts, it was doable for me. The oscillator was the most uneasy, as the pads are almost completely under the component. It seems ok, but time will tell. The MAX IC and the Falcon DAC were easier, for most of the time I used the solder pump after applying a lump of solder, until I found a way to remove most of the lump from the tip to apply solder pin by pin.

I had to rework the DAC though as I had two solder bridges, the first easily removed using the "lump & pump" technique ; I struggled with the second one (pin 3 & 4) until I checked on the schematics that they both were grounded, then I covered my mess with a nice bridge :D . I also had a bend pin (pin 2) after soldering, I succeeded to straighten it.

All in all, I have to harvest the ROM port, all the IC from the donor machine, and using the donor PSU, it seems that I could try a "first light" by the end of the year.


Note : I didn't work on the PLCC Socket of the CPU, as I have a DIP64 version that I plan to use with the 16MHz ST BOOSTER at some point. For the time being, I will plug it directly on one of the 5V bus port.

Epilogue : after cleaning, it turns out that I forgotten to solder the 32.768 kHz crystal required for the RTC... see you next time, crystal...

Progress :cheers:

Before going back to work, a last session. It's time to harvest some parts from the donor machine.

Obviously, the socketed IC are not a problem.


And once again, I got some more XP with the solder pump and the solder wick...


But one pins of one ACIA got K.I.A... the one soldered to ground... Well, anyway I need only one acia for the IKBD to navigate through the diagnostic software...


Also, it's fortunate that I do not intend to use again this motherboard.

Anyway, time to cleanup my mess in the living room...

3 years later...

Well, I had been stuck with the optocoupler socket that I had tombstoned, and could not remove to rework. I even had a big blob of solder shorting the ground pin with the next pin. Anyway it was stuck, and me too.

Since recently I got myself a big soldering iron tip (a 900M-T-5C) that did wonder at melting solder even on copper pours, I decided to give it a try, and I could effectively remove the socket and clean the pads.

However a small track has been damaged, so I did a little bit of repair.


Then I reinstalled the socket.


After that I reworked the joints of the reset button (before/after)


Then I reworked the big outer pins of the VGA port (before/after)


Finally, I installed the socket for the blitter (all the PLCC sockets are themselves socketed using strips of turned pins, that was a fancy of mine at the time), thus finally a little bit of progress...


I don't know when I will continue, but I do not give up.

Don't give up! You haven't deployed the Omega 13 yet...! :lol:

Looking awesome!!