But its versatility and wide range of inputs means that it has retained its place in my capture setup.īreakout has a few beeps. Sure, it's not great at handling the Apple ][, as we saw in the composite comparison. The above screenshots was taken with the Framemeister, hence the awful rainbow banding on the text.
Having already implemented it in hardware for Atari (though his design was not used), computer enthusiast Steve Wozniak wanted to make a computer that could run it in BASIC. While a computer, the Apple ][ was also designed around a single game: Breakout.
In Jeremy Parish’s NES Works series on YouTube, he notes that the Famicom/NES was designed around the game Donkey Kong. Of course, it drops you in the monitor afterwards, so have fun with that, my BASIC-using friend. Of course, assembly language can do better because it runs a lot faster the Apple ][ rom includes a beep routine you can access by calling CALL -16336. That low tone is probably the highest-pitched tone you can achieve in BASIC. (I just used X and never looked at it because the processor and BASIC think you’re reading memory, it’ll want somewhere to put the result) You may not hear anything, but if you do it’ll be the faintest click. If you have an Apple II or an emulator, go to Applesoft and type in X=PEEK(49200), where X can be any variable. Let’s see and hear how limited this is in reality. This is agonizingly low-level to make a 1000 Hz tone, like the famous Apple ][ has no timers or interrupts the only way to time is by knowing the processor clock frequency, and counting your cycles. One write to the address energizes the electromagnet. The speaker is a paper diaphragm controlled by an electromagnet. (In decimal this is 49200, so remember that for later) This sort of “memory-mapped IO” may seem strange, but it’s actually very common even today.Īnd when I say controls the speaker, I mean literally controls the speaker. In this case, address $C030 controls the speaker. This is just a memory address that isn’t actually memory the 6502 processor can only access memory, so all IO must pretend to be a memory address. But still! 1977!Īnd what is that sound support? The Apple ][ has a built-in speaker with no other audio output. And in 1979 Atari’s 8-bit computers introduced home users to the POKEY.
The PET 2001 and the TRS-80 Model 1 didn’t of course, once Commodore added a similar beeper speaker to the PET and Tandy users realized they could use the microphone jack for audio that lead disappeared. Why am I so critical? The Apple ][ has the best built-in audio of the 1977 trinity, after all. Today, we’re going to pick that up again, and look at fixing one of the major weak points of my lovely Apple ][ slander immediately! Remember this was a retro computing blog? A certain cookie company remembers, but if they want their name shout-out they’re going to have to send me some cookies.