41 min
The Justified Ancients of Mu Mu Dan’s MEGA65 Digest Podcast
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- Tecnología
[Did you know: All issues of the Digest have an audio version! Search for “Dan’s MEGA65 Digest” in your favorite podcast app, or check out the audio player at the top of each issue. — Dan]
There are two methods for making sound and music with the MEGA65, as it is currently implemented. The first method is the four SID chips, programmable devices that generate waveforms with requested parameters using analog electronic components. We took a dive into the SID chips back in—November 2022?? How long have I been doing this?? …
The MEGA65 can produce sound another way. Pulse-Code Modulation (PCM) describes a waveform as a sequence of values over time, literally the shape of the desired waveform as a series of high and low numbers, as if drawn on a graph. The computer feeds these numbers into a device called a Digital-Analog Converter (DAC) that produces the waveform in that shape, as if rapidly changing the position of a speaker membrane according to each value. The MEGA65 has four DACs, and these waveforms are mixed with the rest of the audio system to produce the stereo audio output of the computer.
With PCM, a computer can reproduce real-world sounds captured by a microphone, such as human speech or musical instruments. Today, we take this extremely for granted: modern computers generate pretty much all sound using PCM waveforms. We used to call this “digitized sound,” in contrast with “synthesized sound.” Now we just call it “sound.” While PCM gives a computer program much more control over the generated sound, the trade-off is memory: relative to the memory sizes of 1980’s computers, PCM sound data takes a huge amount of space, depending on the length and quality of the sounds.
In this issue, we’ll look at how to control the MEGA65’s DACs to play digitized sound, as well as techniques for wrangling sound data for use in your programs. As usual, we’ll spend a bit too much time nerding out on theory and file formats.
Are you ready? Here we go.
Featured Files
Bomb’em All by btoschi, an explosive action game for two to four players. Drop bombs, pick up items, and break through walls while trying to trap your opponents in the blast zone. The game supports the Four Fun joystick adapter for four joysticks, or can be played with a mix of joystick and keyboard controls.
BASIC Star Galactica by jim_64, a space battle adventure. Destroy the Cylons and protect the fleet—and the future of humanity. Don’t miss the downloadable, printable disk label and manual.
fredrikr has prepared the fourth in his series of text adventure game bundles for the MEGA65, featuring modern classics from the interactive fiction community. This pack includes a variety of games released from 1995 to 2023, all playable on the MEGA65 thanks to the Ozmoo Z-machine player. (See the Digest from October 2022 for more on Ozmoo and MEGA65 adventure gaming.)
Another arcade core from muse! In Ghosts’n Goblins (1985), you are brave knight Sir Arthur, on a quest to save the Princess Prin-Prin. Don your armor—and take care not to lose it—while fighting waves of zombies, giants, demons, and other monsters. This classic from Capcom is considered one of the best video games of all time—and one of the most difficult. As with the other arcade cores, you will need to find the game ROM online, and follow the instructions to install it.
In Stranded, a graphical adventure game by Magnus Heidenborn, your boat has crashed and washed ashore a deserted island. Magnus wrote Stranded for the Commodore 64, specifically the modern TheC64 clone. Gurce ported it to the MEGA65, and added original music. I especially appreciate the novel keyboard-based linear travel and exploration mechanic, which works around common issues with point-and-click adventure games. Check it out!
Expansion board progress
Paul is making progress on the MEGA65 expansion board project. As we reviewed in a previous issue, this project intends to produce an internal hardware e
[Did you know: All issues of the Digest have an audio version! Search for “Dan’s MEGA65 Digest” in your favorite podcast app, or check out the audio player at the top of each issue. — Dan]
There are two methods for making sound and music with the MEGA65, as it is currently implemented. The first method is the four SID chips, programmable devices that generate waveforms with requested parameters using analog electronic components. We took a dive into the SID chips back in—November 2022?? How long have I been doing this?? …
The MEGA65 can produce sound another way. Pulse-Code Modulation (PCM) describes a waveform as a sequence of values over time, literally the shape of the desired waveform as a series of high and low numbers, as if drawn on a graph. The computer feeds these numbers into a device called a Digital-Analog Converter (DAC) that produces the waveform in that shape, as if rapidly changing the position of a speaker membrane according to each value. The MEGA65 has four DACs, and these waveforms are mixed with the rest of the audio system to produce the stereo audio output of the computer.
With PCM, a computer can reproduce real-world sounds captured by a microphone, such as human speech or musical instruments. Today, we take this extremely for granted: modern computers generate pretty much all sound using PCM waveforms. We used to call this “digitized sound,” in contrast with “synthesized sound.” Now we just call it “sound.” While PCM gives a computer program much more control over the generated sound, the trade-off is memory: relative to the memory sizes of 1980’s computers, PCM sound data takes a huge amount of space, depending on the length and quality of the sounds.
In this issue, we’ll look at how to control the MEGA65’s DACs to play digitized sound, as well as techniques for wrangling sound data for use in your programs. As usual, we’ll spend a bit too much time nerding out on theory and file formats.
Are you ready? Here we go.
Featured Files
Bomb’em All by btoschi, an explosive action game for two to four players. Drop bombs, pick up items, and break through walls while trying to trap your opponents in the blast zone. The game supports the Four Fun joystick adapter for four joysticks, or can be played with a mix of joystick and keyboard controls.
BASIC Star Galactica by jim_64, a space battle adventure. Destroy the Cylons and protect the fleet—and the future of humanity. Don’t miss the downloadable, printable disk label and manual.
fredrikr has prepared the fourth in his series of text adventure game bundles for the MEGA65, featuring modern classics from the interactive fiction community. This pack includes a variety of games released from 1995 to 2023, all playable on the MEGA65 thanks to the Ozmoo Z-machine player. (See the Digest from October 2022 for more on Ozmoo and MEGA65 adventure gaming.)
Another arcade core from muse! In Ghosts’n Goblins (1985), you are brave knight Sir Arthur, on a quest to save the Princess Prin-Prin. Don your armor—and take care not to lose it—while fighting waves of zombies, giants, demons, and other monsters. This classic from Capcom is considered one of the best video games of all time—and one of the most difficult. As with the other arcade cores, you will need to find the game ROM online, and follow the instructions to install it.
In Stranded, a graphical adventure game by Magnus Heidenborn, your boat has crashed and washed ashore a deserted island. Magnus wrote Stranded for the Commodore 64, specifically the modern TheC64 clone. Gurce ported it to the MEGA65, and added original music. I especially appreciate the novel keyboard-based linear travel and exploration mechanic, which works around common issues with point-and-click adventure games. Check it out!
Expansion board progress
Paul is making progress on the MEGA65 expansion board project. As we reviewed in a previous issue, this project intends to produce an internal hardware e
41 min