There’s exciting news for Commodore 128 enthusiasts—hkzlab has just dropped a brand-new SRAM adapter designed specifically for C128 systems with the 310381R7 motherboard. This adapter replaces the aging DRAMs with a modern static RAM setup, giving your classic machine a new lease on life.
But before you go rushing in with your soldering iron—hold up! To install this upgrade, you’ll need to carefully remove and socket the original DRAM ICs. And no, this isn’t the time to channel your inner mad scientist. Cutting off DRAM legs is not the move. Let’s save the violence for the arcade games, okay?
What Makes This SRAM Adapter Special?
Flexibility in Component Choice
Whether you’re a fan of surface-mount or through-hole, you’re covered. The board supports both SMD and DIP components.
Easy Installation
Once you’ve got your DRAM chips socketed, the adapter plugs in and pops out without a fuss. It’s a clean and reversible upgrade—perfect for hardware tinkerers who like to keep things tidy.
Thoughtful Design
The adapter was crafted using KiCad EDA, an open-source favorite among hardware developers.
Bill of Materials
Here’s what you’ll need to build it yourself:
| Component | Qty | Type / Value | Notes |
|---|---|---|---|
| C1, C2, C3 | 3 | 100nF ceramic cap, SMD 1206 or 2.54mm through-hole | Standard decoupling caps, rated 10V or higher |
| C5, C6 | 2 | ~82–820pF ceramic cap, SMD or THT | Optional for CAS timing tweaks—normally unnecessary |
| U1 or U4 | 1 | 128Kx8 SRAM, DIP32 or SOP32 | Tested with 85ns 628128 chips; install one or the other, not both |
| U2 | 1 | 74HCT00, DIP14 or SO14 | Can substitute with ACT/ALS/LS/F types; HC is not recommended |
| U3 | 1 | 74HCT573, DIP20 or TSSOP20 | Again, ACT/ALS/LS/F are fine; only HCT has been tested so far |
| J2 | 1 | Angled header or wire | Connects to second CAS line (U38 pin 15) |
| Headers | 1 | 40-pin 2.54mm machined header strip | Cut into 4x 8-pin and 6x 1-pin pieces, solder on underside |
Want One?
You’ve got a couple of options:
- Order the pre-made board directly from PCBWay to support hkzlab.
- Or, if you like to get your hands dirty, download the Gerber files and have the boards printed at your preferred fab house.
Either way, it’s a brilliant little project that brings fresh performance to your vintage C128—no need to rely on those flaky old DRAM chips anymore!
. Say goodbye to flaky DRAMs! Easy install, KiCad-designed, and available now.){kind=link}