IBM PS/2, DS1287 – nwX287

Welcome! Let's tackle a fundamental repair on the IBM PS/2 Model 30 286: the replacement of the Real Time Clock (RTC), specifically the Dallas DS1287, with a modern alternative, the nwX287 by Necroware.

IBM Computer Configuration Errors

The Dallas DS1287, also found in the IBM PS/1, is the system clock of these fascinating computers. With 64 bytes of RAM for system configuration and clock log management, it plays a crucial role in maintaining your computer's configuration as well as the date and time. However, after years of honorable service, the DS 1287's internal battery tends to run out, causing configuration and time problems, as I found on the IBM PS/2 Model 30 286, which showed errors 161 and 163 at startup. The same problem is found on an IBM PS/1 Model 2011.

Various Alternatives to Fix DS1287 Issue

1. Buying a new Dallas DS 1287: This option may be the most straightforward, but finding a reasonably priced DS 1287 with a working battery can prove to be a challenge. I tried to buy them on AliExpress, but they never arrived. I'll try again!

2. Milling the original DS1287: A more advanced option involves modifying the original DS1287 to reach the internal battery contacts and installing a new external battery.

3. Modern alternative with nwX287: In our case, I opted for Necroware's nwX287, a modern alternative designed for these dated chips. It has a battery holder that allows you to replace the CR 1220 battery as needed. In addition, it is available at a reasonable price.

The nwX287 chip is also compatible with the IBM PS/1 computer. In the model I have in my collection, the Dallas DS1287 is located under the hard disk.

Step-by-step procedure for replacing the DS1287

🔧 In the video, I show you step by step the process of replacing the Dallas DS1287 Real Time Clock. We remove the old chip from the motherboard of our IBM PS/2 Model 30 286 and install the new nwX287.

On this computer, the repair was very fast! In fact, the DS1287 is mounted on the motherboard via a socket, which makes the extraction and reassembly procedure really simple and immediate.

Let's also see how to boot your computer with the IBM Starter Disk (the configuration diskette specific to your computer model). This floppy disk is used to analyze error codes and reconfigure the system.

Bar talk!

But that's not all! In the fascinating world of vintage computers, challenges and experiments are the order of the day. Let's talk a bit about my ongoing projects with IBM PS/2 Model 30 computers, both the Intel 8086 processor version and the Intel 286 processor version.

Among the various experiments that are coming to life, I remember the upgrade of the Intel 8086 processor with the NEC V30, the installation of the mathematical coprocessor and the transfer of files to modern computers via FastLynx and serial connection.

If you're a fan of vintage computers, don't miss the details and adventures I share on the YouTube channel @ValorosoIT. I'm also on TikTok, Instagram, Facebook...

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