---
title: "PCjrNet"
url: "https://maker.wiznet.io/WIZnet/projects/pcjrnet/"
markdown_url: "https://maker.wiznet.io/WIZnet/projects/pcjrnet/md"
type: "UCC: User Created Content"
author: "SHAOS"
author_url: "https://hackaday.io/project/163856-pcjrnet"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "SHAOS"
original_url: "https://hackaday.io/project/163856-pcjrnet"
published: "2023-02-14"
language: "en"
likes: 2
views: 288
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# PCjrNet

> DIY Ethernet board for IBM PCjr

Original author: SHAOS (source: https://hackaday.io/project/163856-pcjrnet)

## Article

WizNet module that I plan to use is [WIZ812MJ](https://www.digikey.com/product-detail/en/wiznet/WIZ812MJ/1278-1010-ND/3829654) and it has chip W5100 on board that is able to work in so called “indirect mode” when internal 32KB memory are accessible not through full-scale 15-bit address bus, but through 4 registers (addressed by only 2 address lines) and I plan to use exactly this because of lack of address lines in modem slot of IBM PCjr.

---

Source: https://maker.wiznet.io/WIZnet/projects/pcjrnet/