In this video, I give an overview a pair of PCBs that facilitate upgrading a Commodore 16 (and Commodore 116) to utilize 64KB of RAM. The PCBs are designed to fit directly into the system board without requiring a socket to act as a riser, and do not require cutting traces or lifting pins (as is commonly suggested in variants of this modification). In the last part of the video, we review why this modification is possible by studying the Commodore Plus/4 and Commodore 16 schematics.

Please use the following time-code index to jump to relevant sections in the video.

0:00 Intro
0:42 Preparing for the modification
2:46 Assembly and overview of PCB
6:08 Locating CPU address lines vias
8:50 Address line header installation
10:38 DRAM module installation
11:35 Addressing PCB installation
13:35 Addressing wire installation
14:43 16KB and 64KB memory tests
16:35 How to acquire PCB/kit
17:07 Schematic overview
17:40 How the computer queries DRAM
18:17 Plus/4 schematic - Memory addressing
19:13 C16 schematic - Memory addressing
20:34 Memory module selection
22:03 Closing comments


Purchase Options:

ebay.us/TI6mKU

PCB Dimensions: 28mm x 21mm (each half)
U7 PCB Overhead (relative to TOP): 7.0mm above pins 9-16 (*); 6.4mm below pins 1-8; 3.8mm above pins 1,16 (IC notch); 6.4mm below pins 8,9.
U8 PCB Overhead (relative to TOP): 6.4mm above pins 9-16; 7.0mm below pins 1-8 (*); 3.8mm above pins 1,16 (IC notch); 6.4mm below pins 8,9.
(*) Approximated due to filing of edge.


Music:

"Indiana" by Morten Kristensen (MSK) of Crest (1992)
deepsid.chordian.net/?file=/MUSICIANS/M/MSK/Indian…


References:

"Desoldering DIP/Through-Hole ICs With Inexpensive Tools"
   • Desoldering DIP/Through-Hole ICs With Inex...  

"Technique for safely desoldering through-hole ICs" from Adrian Black
   • How to remove chips without damaging the c...  

"Installing a MOS 6510 adapter with a Commodore 16, 116, or Plus/4"
   • Installing a MOS 6510 adapter with a Commo...  

"Commodore 16 64K Upgrades" from Tynemouth Software
blog.tynemouthsoftware.co.uk/2019/02/commodore-16-…
web.archive.org/web/20201001133418/http://blog.tyn…

264-series Schematics and Troubleshooting Guides from Bo Zimmerman:
www.zimmers.net/anonftp/pub/cbm/schematics/compute…