Author Archives: Michal Necasek

EMM386 and VDS: Not Quite Working

Posted on February 26, 2020 by Michal Necasek

The other day I set out to solve a seemingly simple problem: With a DOS extended application, lock down memory buffers using DPMI and use them for bus-mastering (BusLogic SCSI HBA, though the exact device model isn’t really relevant to … Continue reading →

Posted in Bugs, Development, DOS Extenders | 2 Comments

A Brief Visit to Disk Geometry Hell

Posted on February 20, 2020 by Michal Necasek

Several weeks ago I thought I’d install NetWare 3.12 in a virtual machine using the BusLogic SCSI controller emulation. While configuring a 1.5 GB virtual drive, I thought I should be safe and not run into any trouble with a … Continue reading →

Posted in BusLogic, IBM, NetWare, PC architecture, Storage | 32 Comments

Emulating EtherLink

Posted on January 31, 2020 by Michal Necasek

Spurred by the discovery of a pre-release OS/2 NetWare Requester from early 1988 with a very thin selection of drivers, several months ago I decided to write emulation of the classic 3Com 10Mbps Ethernet 3C501 card, also known as EtherLink. … Continue reading →

Posted in 3Com, Networking, PC hardware, PC history, Virtualization | 33 Comments

1987 Networking: ELS NetWare 286 Level I 2.0a

Posted on January 24, 2020 by Michal Necasek

A rare find recently turned up: NetWare from 1987, specifically the low-end ELS variant of NetWare 286 version 2.0a (ELS may be claimed to mean Entry Level System or maybe Entry Level Server, but at least originally it stood for … Continue reading →

Posted in 286, 3Com, Kryoflux, NetWare, Networking | 29 Comments

Another Strange 286 Board

Posted on January 20, 2020 by Michal Necasek

The OS/2 Museum sometimes seems to have a knack for acquiring hardware so obscure that it cannot be even identified. One of the more recent arrivals was a seemingly typical Baby AT 286 board with an 8 MHz CPU. The … Continue reading →

Posted in 286, PC hardware, PC history | 28 Comments

More Fun with ISA DMA

Posted on January 13, 2020 by Michal Necasek

A reader comment on a previous post on ISA DMA pointed out that UMBPCI (or rather the DMACHK utility distributed with it) does something unusual with regard to ISA DMA. There was a suspicion of somehow accomplishing the mythical memory-to-memory … Continue reading →

Posted in PC architecture, PC hardware, Software Hacks | 8 Comments

MS OS/2 SDK Document Dump

Posted on January 3, 2020 by Michal Necasek

The Microsoft OS/2 1.0 SDK library section got a big fat update. Over the holidays I managed to finalize and upload about 25 PDFs, some of which have been lying on my NAS in 98% completed state for almost 10 … Continue reading →

Posted in Documentation, Microsoft, OS/2 | Leave a comment

The Cape Cod Disaster

Posted on December 16, 2019 by Michal Necasek

Here’s a motherboard Intel very quickly wanted to forget about: It’s the Intel CC820—or Cape Cod—desktop board, a product that was late to market (not unusual) and within a few months, the subject of a recall (quite unusual). As the … Continue reading →

Posted in Bugs, Intel, PC hardware, PC history, Pentium III, RDRAM | 47 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

The Danger of Datasheets

Posted on December 11, 2019 by Michal Necasek

A few days age I came across an article about the 8237 DMA controller in an old German computing magazine (DOS Extra, issue 1 ’87/88, page 123, Schnelle Speicherverwaltung mit dem DMA-Controller, or Fast memory management with the DMA controller). … Continue reading →

Posted in Corrections, PC hardware, PC press | 29 Comments