Hi guys, just wanted to share this here since it was grshaws original post about his A2000 build that got me thinking about it in the first place.
My whole "retro journey" started a few years back when I found out that people still made games for the Commodore 64. I decided I wanted one, and got an old machine from ebay. It turned out to have a few issues, of course. Then I bought another mobo for parts to repair it, then I decided I could make them both work, and you get the picture. It kind of took off from there.
Since I was an Amiga owner back in the day as well, I got quite excited when I found out that this british gentleman named Rob had done a remake of the Rock Lobster rev. 8, the A500+ motherboard. With the 2mbs of chipram and the updated original chipset that was my dream machine in the age when I first got hooked. I decided to try my hand building one. Long story short, it wasn't hitch free, but I got there in the end - with a lot of help from the knowledgeable and friendly people on the A500++ discord group.
It's a great project and one that I really recommend, get the board from Rob's Tindie store: https://www.tindie.com/stores/bobsbits/
With that one working I needed a new project, and that's when I remembered reading grshaws post about the A2000 and the Floppie209 remake. So I got this:
...and yet again, big thanks to Rob and the discord guys. He got a batch of the Floppie209 boards made, and a group of the guys on the discord got started making their own A2000s, including myself. And of course thanks to Floppie209 himself, if he's on here! Reeeally nice board, with some great thouches.
This one got done a lot faster than the A500++, I guess a bit of training helps:
But the soldering isn't all, of course. This weekend I eventually got around to trying the newly built board out. Yet again, not hitch free
At first I just got a black screen. One of the things Floppie209 added to the original design, was a power LED and LEDs for the 5V and the 12V lines right on the board. They lit up nicely, so I knew at least something was going on in there.
My first thought was to change out the CPU. No change. Then I remembered: I had a dead oscillator lying around from my A500++ build. I had somehow forgotten about that and tried to plug that one in on my new board. I desoldered an old one from an old A500 board I had lying around, and plugged that one in the A2000 (it's a socket in there). Flipped the swith, hey presto, it worked!
Ok. I got the kickstart screen - for a while. Then it would flicker and go out. Diagrom would run - for a while, before the screen would fill with artifacts and the thing would freak out on me. Dang. What to do? What not to do! I swapped out and tested every single chip I had spares for. Agnus, Gary, Paula, the CIAs, Denise, the vidiot, the RAM, some of the logic chips, even Buster. No change. Then I decided that the PLCC socket for Agnus was not thrustworthy. Late saturday night I broke out my desoldering gun, doused the board in flux gel, crancked the heat up to 420C and desoldered all the 84 pins.
Woke up on sunday with the slight feeling I might have overdone things again. So I placed the kids in front of the Playstation and had a cup of coffee while i quitely soldered in a new PLCC socket.
Flipped the switch. EGGSACTLY the same behaviour.
Then I sat thinking for a while. I had switched out everything, right? Something wrong with the caps? A partly cold solder joint? Then it dawned on me. The CPU had sat in there since BEFORE I swapped out the dead oscillator. I pulled out my old, beatiful ceramic 68000 and placed a 68010 I got as a spare for the project in there. Oh well
It runs like an eager little puppy now. And it was great fun! Now I'll do some work to make the old case I bought look a little better, I've gotten a lot of inspiration from your posts on that, intric8! Here's a few more pictures of my newly built machine:
Too bad this guy wasn't healthy, I really wanted this one to work: