Author Archives: Michal Necasek

OS/2 1.2 EE DAP

Posted on June 2, 2021 by Michal Necasek

That same shoebox I mentioned the other day also contained three plain cardboard 3.5″ floppy boxes with a set of disks that look like this: Once again, despite the plain-looking labels, these are mass-duplicated floppies, which is handy because Kryoflux … Continue reading →

Posted in Archiving, IBM, Kryoflux, OS/2, PC history | 2 Comments

Like New

Posted on May 31, 2021 by Michal Necasek

About twenty years ago, I bought a used IBM Model M keyboard with a PS/2 connector. I believe it cost me around $5-$10 plus shipping at the time. A good investment, given that this sort of keyboard is probably worth … Continue reading →

Posted in IBM, Keyboard, PC hardware | 5 Comments

Archival Puzzles

Posted on May 28, 2021 by Michal Necasek

Every now and then I attack the large amount of floppy disks in my basement and run a bunch of them through Kryoflux. This time it was a shoebox full of OS/2 related floppies. Among them was a very incomplete … Continue reading →

Posted in Archiving, IBM, Kryoflux, OS/2, Pre-release | 30 Comments

DOS SMB Client Performance

Posted on May 20, 2021 by Michal Necasek

Recently I had the need to use several different DOS VMs that all used a SMB network client. Although I did not use networking heavily, I noticed that there are massive differences in performance between the VMs. Copying a circa … Continue reading →

Posted in DOS, IBM, Microsoft, Networking | 15 Comments

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

Installing IBM OS/2 1.0 in a VirtualBox VM

Posted on April 30, 2021 by Michal Necasek

Some time ago I wrote that IBM OS/2 1.0 and 1.1 cannot be installed in a VM due to the way it switches between real and protected mode. At the time I did not realize that there was another obstacle, … Continue reading →

Posted in OS/2, VirtualBox, Virtualization | 18 Comments

Nobody Expects…

Posted on April 14, 2021 by Michal Necasek

…the Spanish Inquisition! Well, that too, but also nobody expects that a bland, run-of-the mill Novell NE2000 NDIS driver would crash/hang just because it runs on 486 or later CPUs. I wanted to try the “basic” DOS redirector shipped with … Continue reading →

Posted in 486, Bugs, Intel, Microsoft | 7 Comments

Was the NE2000 Really That Bad?

Posted on April 9, 2021 by Michal Necasek

Over the last few months I have been on and off digging into the history of early PC networking products, especially Ethernet-based ones. In that context, it is impossible to miss the classic NE2000 adapter with all its offshoots and … Continue reading →

Posted in 3Com, Ethernet, Networking, Novell, PC history | 15 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

8237A DMA Page Fun

Posted on March 28, 2021 by Michal Necasek

The other day I was trying to fill a couple of gaps in my understanding of the Intel 8237A DMA controller documentation. I wrote a small testcase that performed a dummy transfer and modified the base address and count registers … Continue reading →

Posted in Intel, PC architecture, PC history | 5 Comments