Category Archives: Software

Connecting my PC XT clone to the network: Part 1 – Ethernet adapter

I currently work on connecting my PC XT clone to my home network. But why? What are the benefits of connecting a 30 years old machine to the network?

It gives me one more reason to fire up my Pravetz 16 🙂 It would be cool chatting on IRC on that monochrome (green and black) monitor, running an FTP server for file transfers between the PC XT and other PC’s on the network or an HTTP server, etc…

The PC XT will be connected to the network using the so called ‘Thin Ethernet‘ (10Base2) using a coaxial cable and BNC connectors. Why? Because finding 8-bit ISA compatible Ethernet card is extremely rare nowadays, and chances to find one with RJ45 connector are close to zero.

My long search for 8-bit ISA network adapter finally gave results and for 10$ I’m an owner of PLUS & PLUS PCN-001.

Plus & Plus PNC-001 Ethernet adpater

It’s 10Mbps Ethernet card with support for coaxial and DIX transceiver wiring. It has an option for a boot ROM but mine don’t have a chip. This card is a clone of AMERICAN RESEARCH CORPORATION PNC-001, it’s NE1000 compatible and supported by the NE1000 driver for DOS available in the many-other-drivers.zip along with many other packet drives, thanks to Crynwr Software!

After a bit of googling I found the required information on how to configure the adapter here. That exact same information is copy / pasted at the end of this post for future references.

Setting the IRQ to 2, the I/O base address to 200h, and disabling the boot ROM and DMA settings, changing the cable type jumpers from ‘DIX transceiver via DB-15 port’ to ‘RG-58A/U 50ohm coaxial’ I booted the PC, loaded the NE1000 driver

C:\>ne1000 0x7E 2 0x200

UPDATE 16/02/2016: I was having problems receiving network packets, changing the IRQ to 5 and I/O base address to 0x280h resolved the problem.

NE1000 packet driver loaded

and success! The card is working! 10$ well spend 🙂

NOTE: Installation instructions for packet drivers are in INSTALL.DOC (many-other-drivers.zip)

The Ethernet adapter is now configured and working properly. This concludes Part 1 of the series of articles about connecting my PC XT to the network. Later I will review other vital network component. The Surecom Ether Perfect 517T hub with BNC connector.

PLUS & PLUS (AMERICAN RESEARCH CORPORATION) PNC-001 Jumper settings (Information taken from Total Hardware 1999 page on the topic available here.)

I/O BASE ADDRESS

Address	SW1/1	SW1/2	SW1/3	SW1/4	SW1/5
200h	Off	On	On	On	On
220h	Off	On	On	On	Off
240h	Off	On	On	Off	On
260h	Off	On	On	Off	Off
280h	Off	On	Off	On	On
2A0h	Off	On	Off	On	Off
2C0h	Off	On	Off	Off	On
2E0h	Off	On	Off	Off	Off
300h (default)	Off	Off	On	On	On
320h	Off	Off	On	On	Off
340h	Off	Off	On	Off	On
360h	Off	Off	On	Off	Off
380h	Off	Off	Off	On	On
3A0h	Off	Off	Off	On	Off
3C0h	Off	Off	Off	Off	On
3E0h	Off	Off	Off	Off	Off

BOOT ROM

Setting	SW1/6
Disabled (default)	Off
Enabled	On

BOOT ROM ADDRESS

Address	SW1/7	SW1/8	SW1/9	SW1/10
C0000h	On	On	On	On
C4000h	On	On	On	Off
C8000h	On	On	Off	On
CC000h	On	On	Off	Off
D0000h	On	Off	On	On
D4000h	On	Off	On	Off
D8000h	On	Off	Off	On
DC000h (default)	On	Off	Off	Off
E0000h	Off	On	On	On
E4000h	Off	On	On	Off
E8000h	Off	On	Off	On
EC000h	Off	On	Off	Off
F0000h	Off	Off	On	On
F4000h	Off	Off	On	Off
F8000h	Off	Off	Off	On
FC000h	Off	Off	Off	Off

INTERRUPT REQUEST

IRQ	JP1A	JP1B	JP1C	JP1D
2	Closed	Open	Open	Open
3 (default)	Open	Closed	Open	Open
4	Open	Open	Closed	Open
5	Open	Open	Open	Closed

DMA CHANNEL

Channel	JP1F	JP1G	JP1H	JP1I
DMA1 (default)	Closed	Open	Closed	Open
DMA3	Open	Closed	Open	Closed

CABLE TYPE

Type	JP2A – JP2F
RG-58A/U 50ohm coaxial (default)	Pins 1 & 2 closed
DIX transceiver via DB-15 port	Pins 2 & 3 closed

FACTORY CONFIGURED SETTINGS

Jumper	Setting
JP1E	Open

Eclipse Hotkeys Fix

Eclipse on GNU/Linux has an annoying bug with hotkeys for users with multiply keyboard layouts.

For example when the user is working with the English keyboard layout, hotkeys such as “Ctrl-C”, “Ctrl-V” will work as expected, but when switched to different layout (ex: Bulgarian) the keys will no longer work.

After a bit of searching I found a fix for this inconvenience at GitHub.

Thank you “amozzhuhin“!

Console screen resolution (frame buffer) with NVIDIA drivers on Ubuntu, Debian or Linux Mint

After the installation of the proprietary NVidia graphics drivers on Ubuntu, Debian or Linux Mint your console screen resolution will be messed up. As a developer I use the frame buffer console from time to time and I need it at the resolution of my primary monitor (1680×1050). To address the problem (as it’s almost always with GNU/Linux) we need to edit some configuration files and issue some commands.

First start Konsole or other terminal emulator, login as root by typing:

su

and enter your password when prompted.

Using vim, nano or your favourite command line text editor, open /etc/grub.d/00_header. In the example below we are using Vim.

vim /etc/grub.d/00_header

Search for “set gfxmode=${GRUB_GFXMODE}” and below that line add

set gfxpayload=keep

Save and close the file.

Reboot your system and at the Grub2 screen press ‘C’ and type ‘vbeinfo‘. Take a note on the supported frame buffer resolution and choose the one you like. In my case the chosen resolution was 1680x1050x32. Type ‘exit‘ or reboot your system from the restart button.

Start GNU/Linux again, start a terminal emulator, login as root (by typing su) and open “/etc/default/grub“. Uncomment the line “GRUB_GFXMODE=640×480“, change the value after the = sign to the previously chosen screen resolution. In my case:

GRUB_GFXMODE=1680x1050x32

and add the following line below:

GRUB_GFXPAYLOAD_LINUX=keep

Save and close the file.

Still logged as ‘root’ execute the following commands:

update-grub2

update-initramfs -u

Reboot your system. You should now have a frame buffer console with a decent screen resolution.

Diskettes for the Pravetz

I finally got my hands on some 5^1/4” diskettes for the Pravetz. They are in good condition and full of old games and programs. There is also a pack of cleaning diskettes for the floppy drive. I’m still looking for more.

I’m inpatient to find a monitor, to see if this dinasour runs.

Restoration of Pravetz-16 Turbo (IBM PC XT compatible)

My software development career started 20 years ago. It’s sound crazy, but when I was 8, I was introduced to my first computer and Turbo Pascal.

Turbo Pascal IDE

My first computer was Pravetz-16. It was something new and interesting for me, and I was hooked immediately.

Years and technology changed, the old Pravetz died from natural causes and was thrown for recycling.

Now almost 20 years later I felt the urge to have my old computer back and stated searching. It was hard and long search until finally I saw an ad that a scrap depot is selling an old Pravetz computer. Not wasting time I called them and brought it for 100 leva ( around 70 USD ). It was the computer only, with ought the peripherals. Before the deal I asked them to try turning it on. They said it’s starting, so I have it delivered to me.

Front view of the PC

Except from being full of dust, dead spiders and dirt all around and with some minor hardware problems like the serial board apparently dead. This specimen was almost authentic. It’s still has all the marks from the factory and even a warranty card and instruction manual for the floppy disk.

Warranty card. Expired 24 years ago

From the warranty card I found out that this PC was one of the last produced before the collapse of the communist regime in Bulgaria. The production date is 12.12.1989 and it’s apparently the turbo version with the following specs:

CPU: 80286 at 12 Mhz
RAM: 1 MB
HDD: 20 MB
5 1/4″ Inch Floppy drive
LPT printer port
COM port
CGA video card (VDO-3)

Floppy drive instruction manual

Support contact information sticker

Model sticker at the back

Inside of the PC

The power switch

View from the back. You can see couple of dead spiders over the video card

It took me 7 hours to disassemble the PC, clean it screw by scree and put it back together. Every non electrical part was washed and the electrical ones were cleaned with alcohol solution and an old tooth brush. The old Pravetz now shines as new.

I also found a keyboard yesterday, and ordered a pile of floppy disks. They should be here soon.

The keyboard

Now I’m looking for a CGA monitor, to be finally able to turn it on and see will it boot. Meanwhile the keyboard will be disassembled and cleaned.

Life of a software developer

by Vladimir Paskov