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A 1MB chip RAM expansion for the A500+
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A500 Parts Library
a500plus-chipram-expansion.pretty
gerbers
media
README.md
a500plus-chipram-expansion-cache.lib
a500plus-chipram-expansion.kicad_pcb
a500plus-chipram-expansion.net
a500plus-chipram-expansion.pro
a500plus-chipram-expansion.sch
fp-info-cache
fp-lib-table
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README.md

a500plus-chipram-expansion

This is a 1MB chip RAM expansion designed for the Amiga 500+ in KiCad.

a500plus-chipram board image

It is in the experimental phase, but I've assembled it and it appears to be working great. However, you've been warned!

Features

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.

Schematic

A PDF file of the schematic can be found in this repo.

Ordering

I shared the design at Oshpark

BOM

Designator Description
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

Install

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:

a500plus-chipram board install orientation

Thanks

The parts library I've included (and expanded upon) in this repo is "borrowed" from Kai Robinson check out his great projects!

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