Category Archives: DOS

It Was a Problem Back in the Day

Posted on May 19, 2021 by Michal Necasek

Several years ago, I found out the hard way that old versions of DOS have trouble with hard disks with more than 17 sectors per track. To recap, DOS versions older than 3.3 may hang when booting from a hard … Continue reading →

Posted in Bugs, DOS, ESDI, Storage | 26 Comments

MS LAN Manager NDDK Anyone?

Posted on April 2, 2021 by Michal Necasek

For R&D purposes, I would very much like to get my hands on the circa 1991 Microsoft LAN Manager Network Device Driver Kit which was meant to support the development of NDIS 2.0 drivers. While it is obvious that some … Continue reading →

Posted in Development, DOS, Microsoft, Networking, OS/2 | 10 Comments

The Answer To 0x49: Fujitsu FMR

Posted on December 11, 2020 by Michal Necasek

This is a guest post by A. N. Other. The following was originally intended as a comment to “Not MSX Either“, the 4th installment in the hunt for the mysterious 0x69 FAT VBR-start byte which was allowed in DOS. Due … Continue reading →

Posted in DOS, NT, PC hardware, PC history, Undocumented | 7 Comments

Really Atari ST?

Posted on September 21, 2020 by Michal Necasek

This blog has previously examined a very very strange code fragment in the BIOS module of DOS. To recap, when deciding whether a boot sector might have a valid BPB, DOS checks whether the first byte is a relative jump … Continue reading →

Posted in DOS, Microsoft, PC history | 18 Comments

DOS Wireless Networking, Continued

Posted on December 11, 2019 by Michal Necasek

As I recently mentioned, wireless networking is extra difficult when the access point reboots itself at the slightest hint of heavier traffic. The faulty TP-Link router was temporarily replaced with a Netgear WG602 of similar vintage. The Netgear has been … Continue reading →

Posted in DOS, Networking, NFS, TCP/IP, Wireless | 3 Comments

Wireless Networking in DOS

Posted on December 2, 2019 by Michal Necasek

Wireless networking has a long history, longer than most people realize. NCR’s WaveLAN was available in 1990 and of course supported DOS. But WaveLAN was only the precursor to IEEE 802.11 and it is completely incompatible with IEEE-standard networking equipment. … Continue reading →

Posted in DOS, Networking, Wireless | 20 Comments

Why Does Windows Really Use Backslash as Path Separator?

Posted on May 24, 2019 by Michal Necasek

More or less anyone using modern PCs has to wonder: Why does Windows use backslash as a path separator when the rest of the world uses forward slash? The clear intermediate answer is “because DOS and OS/2 used backslash”. Both … Continue reading →

Posted in DEC, DOS, IBM, Microsoft, PC history | 42 Comments

A Word on the CALL 5 Spell

Posted on May 26, 2018 by Michal Necasek

After years of searching for some reasonably widespread DOS application which used the CP/M-style CALL 5 interface and coming up with absolutely nothing, Jeff Parsons of pcjs.org found one: None other than Microsoft Word, specifically the spell checker in the … Continue reading →

Posted in DOS, Microsoft, PC history | 10 Comments

Microsoft Editor

Posted on March 11, 2018 by tenox

(This is a guest post by Antoni Sawicki aka Tenox) In a recent blog post I lamented the lack of a good console/cmd/PowerShell text editor for Windows. During the process I made a rather interesting discovery, that in a fact … Continue reading →

Posted in Development, DOS, Editors, Microsoft, NT, OS/2, Source code, Uncategorized | 23 Comments

WordStar Again

Posted on January 26, 2018 by Michal Necasek

While trying to work on my DOS 5.0 article, I looked at DOS 5.0 build 224 from June 1990, which is the oldest surviving beta of DOS 5.0. And the README contains the following intriguing text, which reminded me of … Continue reading →

Posted in DOS, PC history, WordStar | 74 Comments