Recently my brother decided to complete my Commodore Breadbin collection by donating me a Commodore 16 that he found on ebay. The C16 was in non working condition, however I discovered (thanks to the Plus/4 that TC recently sent me), that the TED and CPU were working, but the TED socket was knackered. I replaced the socket, removed a very strange Datasette bodge that had been done and gave it a working power LED. Then I decided that it deserved to have 64K of RAM like its Plus/4 brother.
I followed the destructions here:
http://mcbx.netne.net/hacks/c16_64k/index.htm
and here:
http://www.commodore16.com/index.ph...9-how-to/148-upgrading-your-c16-to-64-kb.html
But I thought it would be good to get some more photos of the mod online. So here goes!
This is the patient...
To do the mod you will need two 4464 ram chips. I put them in sockets to protect them from dodgy soldering.
As you can see, in the beginning the machine was a standard C16
The two chips highlighted in red are the ones that need to be changed.
As you can see, I used the destructive method to remove the old RAM. Basically I cut the legs off.
I then used tweezers and the soldering iron to heat each remaining leg stump and pull it gently from the board. This leaves all the solder holes covered in solder. My technique to clear the holes is to place a new blob of solder on each via and then heat and suck out the whole lot with a desolder pump. It works quite well. The 80s solder makes a mess of your soldering iron so you need to keep it clean!
With all the solder holes clear, the chip sockets drop straight in without needing to be pushed. I put a bit of solder on the tip of my iron and tack two opposite corner pins in place to stop it falling out. Then I solder each pin in turn properly.
The new RAM just pushes into the sockets. The right way round of course! Notches in the chip line up with notches printed on the board.
At this point you can boot the C16 again. It will still display the standard ram, but it means you probably haven't broken anything yet.
So now you have to attack the board and cut some tracks. First is pin 14 at U8. It is connected to the +5v rail and has to be disconnected. You can see the bridge at the tip of the blade.
The next track is more difficult as it is hidden under the IC U7. It goes from Pin 2 to Pin 16 and is marked with an arrow. Cut it by sliding the tip of your knife between pin 2 and 16. Check with a multimeter that there is no longer a connection between pins 2 and 16.
Now you need to solder new connections so that the CPU can see the extra RAM. U7 pin 2 to CPU pin 21 and U8 pin 14 to CPU pin 22 as pictured.
This is the bit that I messed up as I managed a small short between pins 21 and 22 on the CPU. Don't do that; it took over an hour to find the mistake!
Then you should have more tasty RAM to play with!
I followed the destructions here:
http://mcbx.netne.net/hacks/c16_64k/index.htm
and here:
http://www.commodore16.com/index.ph...9-how-to/148-upgrading-your-c16-to-64-kb.html
But I thought it would be good to get some more photos of the mod online. So here goes!
This is the patient...
To do the mod you will need two 4464 ram chips. I put them in sockets to protect them from dodgy soldering.
As you can see, in the beginning the machine was a standard C16
The two chips highlighted in red are the ones that need to be changed.
As you can see, I used the destructive method to remove the old RAM. Basically I cut the legs off.
I then used tweezers and the soldering iron to heat each remaining leg stump and pull it gently from the board. This leaves all the solder holes covered in solder. My technique to clear the holes is to place a new blob of solder on each via and then heat and suck out the whole lot with a desolder pump. It works quite well. The 80s solder makes a mess of your soldering iron so you need to keep it clean!
With all the solder holes clear, the chip sockets drop straight in without needing to be pushed. I put a bit of solder on the tip of my iron and tack two opposite corner pins in place to stop it falling out. Then I solder each pin in turn properly.
The new RAM just pushes into the sockets. The right way round of course! Notches in the chip line up with notches printed on the board.
At this point you can boot the C16 again. It will still display the standard ram, but it means you probably haven't broken anything yet.
So now you have to attack the board and cut some tracks. First is pin 14 at U8. It is connected to the +5v rail and has to be disconnected. You can see the bridge at the tip of the blade.
The next track is more difficult as it is hidden under the IC U7. It goes from Pin 2 to Pin 16 and is marked with an arrow. Cut it by sliding the tip of your knife between pin 2 and 16. Check with a multimeter that there is no longer a connection between pins 2 and 16.
Now you need to solder new connections so that the CPU can see the extra RAM. U7 pin 2 to CPU pin 21 and U8 pin 14 to CPU pin 22 as pictured.
This is the bit that I messed up as I managed a small short between pins 21 and 22 on the CPU. Don't do that; it took over an hour to find the mistake!
Then you should have more tasty RAM to play with!