Tunneler is a top-down perspective game written in the early 1990s for DOS on IBM-PC compatible computers. Two tanks explore an underground realm, venturing from their protective bases to dig tunnels and find their opponent for battle.

This game was novel in that it allowed two players to battle simultaneously on the same computer, with two windows and a shared keyboard. The game also used the “undocumented” CGA 160 x 200 pixel 16-color graphics mode.

Here are some screenshots. Here is the initial state, with both tanks in their bases. To independently scrolling windows show each player’s view:

Tunneler: Tanks in Bases

Continue reading

This entry was posted on by .

CGA Low Resolution 16-Color Graphics

CGA 16-Color Graphics

The original IBM-PC Color Graphics Adapter (CGA) could display text in 16 colors, but supported only 4 colors when in color graphics mode (at a resolution of 320×200 pixels). It was not widely known that the CGA graphics card could also display a 16-color graphics, albeit at a resolution of only 160×100 pixels. Wikipedia has a good description of the technical details of this low-res graphics mode. Also, see Life Before Demos.

I first came across this low-res graphics mode when I downloaded a game called Round 42, and was enthralled. I had to learn how to achieve this 16-color graphics mode it used. Continue reading

This entry was posted on by .

History & Technical Details

Combat on the Atari 2600I think the concept of Tunneler was inspired by Combat for the Atari 2600 — two players fight it out in simultaneous battle.  (Note the blue & green tanks.)  I thought there weren’t enough concurrent two-player games for the IBM PC.  Tunneler was also an incremental step from a digging/mining game I had written for the TRS-80.

IBM PS2 Model 30

I wrote Tunneler in my spare time between 1989 and 1992 using my IBM PS/2 Model 30.  Tunneler was developed using Turbo Pascal 4 and some hand-coded assembly. No, I no longer have the source code — it was stored on floppy disks that were lost or damaged over the years.

Continue reading

This entry was posted on by .