This is a 1MB chip RAM expansion designed for the Amiga 500+ in KiCad.
It is in the experimental phase, but I've assembled it and it appears to be working great. However, you've been warned!
Small (42mmx52mm), simple design using only a 40 pin (2x20) female 2.54mm connector. The remaining pins are for the RTC which is on-board the A500+, so they are unecessary for RAM expansion. This makes it possible to use a 40 pin connector, which is cheaper and easier to find.
WARNING: make sure you plug it in correctly see the install section below.
A PDF file of the schematic can be found in this repo.
I shared the design at Oshpark
|J1||40P (20x2) female header 2.54mm|
|J2||1x DPDT Sub-Miniature Slide switch (9x4x3.5mm, easily found on Ebay)|
|U1-U2||IS41C16257-35T 4mbit DRAM (256 x 16)|
|C1-C6||100nF 603 SMD capacitor|
|C7||10uF 805 SMD capacitor|
|R1||10K 805 SMD resistor|
Be careful during install to match pin 1 on the expansion with pin 1 on the A500+ memory expansion port! Here's an image of how it should be installed:
The parts library I've included (and expanded upon) in this repo is "borrowed" from Kai Robinson check out his great projects!