Sound producing keyboard in just two lines of BASIC on the Commodore 64

A BASIC two-liner on the Commodore 64, which enables a sound each time you press a key on the keyboard. Written in BASIC, the two lines store values in the memory and creates an IRQ driven routine.
The result is rather disappointing but the interesting thing about this two-liner is the process used through the instruction PRINT to write a short routine in machine language at $C031/49201. The screen RAM is indeed used to store values, which are 6502's opcodes modifying the values in the SID registers and the vector pointing to the interrupt handler $314/$315. This is something that might be obvious for experienced programmers, but not so much for beginners
#c64
#basic
#6502
#commodore64

[@the_eminent_Joshua_E_Hrouda]

One way to make the program smaller or a little more streamlined is to use line numbers 1 & 2 instead of 5 & 10

[@Commodoreretro-programming]

Well, try to use 0 and 1 instead! Yep 0 can be used in BASIC.

[@davedavenport8673]

Interesting how they used the high byte ($EA) of the original IRQ vector, which they jump back to at the end of the code, as the value for most of the SID registers, then STA the voice register with the waveform value to turn on the note. The key bounce feature is great as well. It would be fun to grab the keycode for whatever key is pressed and do some rotate to get it to a higher value and use that as the note high byte of the note, so each key would make a slightly different pitch.

[@davedavenport8673]

ah, nevermind on the EA thing. That is just the starting location for the data that goes into the SID voice 3 registers using the LDA,x opcode.

[@Commodoreretro-programming]

Agree. It could be fun to change the code to get a different sound for each key pressed. It should not be difficult. I'll do it if I have some time.

[@CityXen]

Cool deal man

[@Commodoreretro-programming]

The two lines 5 ?"{clear}jelelid@o@@ble@bhe@bo@a@jb@kkmdol@im@mmdljm@ogjibahmabmddlcanjka@n@@@@b@@h"; 10 ?"@@@@@@@@@o":forf=0to41:A=1024+F+F:B=PEEK(A)*16+PEEK(A+1):poke49201+F,B:next:poke789,192:new

[@przemekbundy]

Bonjour. ça m'est arrivé pour la première fois. sur votre tube. m'a proposé la chaîne française. J'ai grandi sur C64. Salutations de la Pologne.

[@Commodoreretro-programming]

Bonjour et bienvenue. Moi aussi j'ai grandi avec un Commodore 64 :)

[@the_eminent_Joshua_E_Hrouda]

All that typing. All those random-looking letters in the PRINT statement. And all it did was make one note!!?? What a crap program!! Not a bad video. I like how you explained how it worked.

[@Commodoreretro-programming]

Maybe the video focussed on the process and the explanations rather than on the result itself... :)

[@jimphone]

Let's see your more efficient code then. Post it here and maybe he can make a video about it.