Let’s Code MS DOS 0x2C: Noisy 3D Animation

Earlier this year I saw a demo effect using a random noise background and simple wireframe 3D using XOR line drawing to create an interesting visual effect. Building on the 3D Cube program we did a while ago we can reimplement this effect. The magic happens when you pause the animation — or this video. Then the object magically disappears…

What if the Amiga sounded better?

Back in 1985 when the Amiga came out the Paula sound chip was not totally groundbreaking, but better than most of its competitors. It supported four channel stereo PCM playback. This could be used with sampled instruments to get a relatively natural sound. However there were many limitations, many of which due to the software not utilising the Paula to its fullest. Two years later, when the A500 came out, Roland released the MT-32. A consumer grade synthesizer module that was used relatively widely in the MS DOS gaming world, spearheaded by Sierra On-Line. It is a little known fact that you can use the MT-32 also on the Amiga with Sierra adventures such as King’s Quest, Space Quest or Larry. Does the Amiga sound better with the MT-32?

Let’s Code MS DOS 0x2A: Background Adlib Music

We already learned how to program the Adlib sound card to produce percussion and melodic instruments. Now we tackle the problem of getting real music out of it. By utilizing the Reality Adlib Tracker’s playback routine we learn how to program the Programmable Interrupt Timer (PIT) in the PC to get a steady playback of background music.

Commodore PET: 40K RAM with SoftROM

The Commodore PET was one of the first true PCs. The entry model PET 2001 in 1977 came with 8K of RAM. My own PET 3016 from 1979 came with 16K, which I upgraded a while ago to 32K of RAM. This lets us run a lot of software, even interactive fiction games, for example Planetfall and Zork by Infocom. However we can do better! Using the SoftROM expansion we can add an additional 8K of SRAM to our system, that can be used by the Infocom interpreter, or any other software that knows about it and is changed accordingly.

Black Amiga 500

Many a computer from the 1980s is today yellowed and brittle. The plastics age considerably over the decades. You can do some mitigation by retrobrighting with hydrogen peroxide. However for some machines you can even get replacement cases, and in some cases even brand new key caps for the keyboard. Today we will transform a beige Commodore A500 into a black beauty!

Zombie Floppy: How To Revive A Broken 1541 Head

The Commodore 1541 floppy drive is a real workhorse, that was used by millions of C64 users. It came with drive mechanisms from different vendors. The Newtronics/Mitsumi drive assembly has the annoying fault to have their drive heads fail due to some wires going open inside of the read/write head. This is so far not economically repairable. However a clever user by the nickname of Ruuudi on German Forum64 has designed a little bodge PCB to make the half of the head that is still okay to all the work and thus revive an otherwise dead drive.