Author Archives: Michal Necasek

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 | 27 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 | 24 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

Fake vs. Real

Posted on March 2, 2021 by Michal Necasek

After discussing an Adaptec SCSI HBA that was clearly made from recycled parts and likely fake, I wanted to see what a real one looks like. It looks like this: For reference and for comparison, here’s the sketchy one: The … Continue reading →

Posted in Adaptec, Fakes, PC hardware | 6 Comments

Diskette Puzzle

Posted on February 25, 2021 by Michal Necasek

Last week the OS/2 Museum received a classic red NetWare box with all sorts of junk inside: PCI and ISA network cards (most Ethernet, one ArcNET), BNC cabling, one or two manuals, and over a 100 floppies, mostly NetWare but … Continue reading →

Posted in Archiving, Floppies, NetWare | 20 Comments

Complications, Complications

Posted on February 19, 2021 by Michal Necasek

The other day someone asked how hard it would be to modify the Open Watcom linker, wlink, to properly support exports from IOPL segments in OS/2 LX modules. Not terribly hard it turned out, all it needed was to emit … Continue reading →

Posted in Development, OS/2, Watcom | 2 Comments

SCSI HBA Recycling?

Posted on February 10, 2021 by Michal Necasek

Several weeks ago I bought this Adaptec 39160 64-bit PCI SCSI HBA in order to experiment with different HBAs: The motivation was that although I’ve been a happy user of LSI HBAs (SCSI and SAS, PCI and PCIe) based on … Continue reading →

Posted in Adaptec, Fakes, PC hardware, SCSI | 10 Comments