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Vic20-32k ram cart

The8BitEnthusiast·vic20-32k-ram-cart·schematics/vic20-ram-expander.kicad_pcb

Vic20-32k ram cart PCB layout, top view — open source board by The8BitEnthusiast

About the Vic20-32k ram cart PCB

Vic20-32k ram cart is an open source PCB design by The8BitEnthusiast, published on GitHub under the MIT license. It is a 2-layer board measuring 90 × 45 mm, with 5 components from 4 distinct parts.

Other key parts include the V20-Cart-Port, 62256 32K SRAM and 74LS148. By type, the board carries 3 ICs and 2 capacitors.

It belongs with the retro computing designs in this gallery.

From the project

32K RAM Expansion PCB Design and 3D Printed Cartridge Project

After building Ben Eater's 6502 breadboard computer, I undertook this project to see how hard it would be to upgrade the RAM of my VIC-20. After all, the VIC-20 is basically a BE6502 in a case with a video chip and a keyboard. This was also an opportunity to learn how expansion cartridges are designed.

I didn't want to start this project from scratch, so I looked around for prior designs. I eventually landed on this elegant 2-chip memory expansion design from Adam Bergstrom. Absolutely brilliant. As the diagram below shows, there are 4 8K blocks of memory that are empty and available for…

Vic20-32k ram cart, from the project README
From the project README

Main components on the Vic20-32k ram cart

V20-Cart-Port62256 32K SRAM74LS148

Vic20-32k ram cart bill of materials (BOM)

5 components, 4 distinct parts.

QtyPartRefs
1
V20-Cart-Port
U1
1
62256 32K SRAM
U2
1
74LS148
U3
2
.1uF
C1, C2

Vic20-32k ram cart design files

The KiCad project lives in the The8BitEnthusiast/vic20-32k-ram-cart repository on GitHub; these links point at the commit this page was built from.

Vic20-32k ram cart: common questions

How big is the Vic20-32k ram cart PCB?

The Vic20-32k ram cart measures 90 × 45 mm, has 2 copper layers and is 1.6 mm thick.

How many components are on the Vic20-32k ram cart?

5 components, from 4 distinct parts. The full bill of materials is listed on this page.

Where can I download the Vic20-32k ram cart design files?

From the The8BitEnthusiast/vic20-32k-ram-cart repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.

Can I use the Vic20-32k ram cart design in my own project?

Yes, under the terms of its MIT license, which The8BitEnthusiast chose for the repository.

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