The following code will allow you to play a music under interruption, on ZX Spectrum (without using the firmware).<\/p>\n\n\n\n
This code was kindly provided by Gusman<\/strong>. A big thanks to him!<\/p>\n\n\n\n The following code will allow you to play a music under interruption, on ZX Spectrum (without using the firmware). This code was […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":209,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_vp_format_video_url":"","_vp_image_focal_point":[],"footnotes":""},"class_list":["post-2388","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/pages\/2388","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/comments?post=2388"}],"version-history":[{"count":3,"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/pages\/2388\/revisions"}],"predecessor-version":[{"id":2391,"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/pages\/2388\/revisions\/2391"}],"wp:attachment":[{"href":"https:\/\/www.julien-nevo.com\/arkostracker\/index.php\/wp-json\/wp\/v2\/media?parent=2388"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}PrepareMusic:\n ld hl, MUSIC_ADDRESS ;load your song address\n xor a ;subsong 0\n call PLY_AKG_INIT ;call initialization routine\n ret\n\nPlayMusic:\n call Interrupt_Setup ;This function is totally unnecessary, just for readability of the code\n ret\n\nStopMusic:\n di ;disable interrupts\n call PLY_AKG_STOP ;stop the player\n\n IM 1 ;revert interrupt mode to mode 1\n ei ;enable interrupts\n\n ret\n\nPlayer:\n ;your player+music code\n #include \"music.z80asm\"\n\nJP_ADDRESS EQU #FDFD ;JP address\n\n;IM 2 mode must be used on the spectrum to have a custom interrupt handler.\n;The spectrum architecture makes impossible to know what will be on the bus when an interrupt is executed\n;so the handler must be in an address where it's high and low bytes are equal.\n;To be able to store your interrupt handler anywhere three bytes at an address\n;with that characteristic (FDFD in this case) are reserved and written with \"jp Interrupt_Handler\"\nInterrupt_Handler:\n \n push af ;store all registers\n push bc\n push de\n push hl\n push ix\n push iy\n exx\n ex af, af'\n push af\n push bc\n push de\n push hl\n \n ;play music\n call PLY_AKG_PLAY\n pop hl\n \n ;restore all registers\n pop de\n pop bc\n pop af\n ex af, af'\n exx\n pop iy\n pop ix\n pop hl\n pop de\n pop bc\n pop af\n \n ;reenable interrupts\n ei\n ;return from interrupt handler\n ret\n\n.align 256\nInterrupt_Table:\n ;interrupt table must be aligned at page boundary\n ;with 256 + 1 bytes, all with the same value\n .defs 257\n\nInterrupt_Setup:\n di ;Disable interrupts\n ld de, Interrupt_Table ;load interrupt table address\n ld hl, JP_ADDRESS ;load \"JP\" address\n ld a, d\n ld i, a ;load I with the interrupt table high byte\n ld a, l ;load a with lower byte of JP address (indifferent to use H or L, both must be equal)\n\nInterrupt_Table_Loop:\n ld (de), a ;fill the table\n inc e\n jr nz, Interrupt_Table_Loop\n inc d ;write the 257th byte of the table\n ld (de), a\n ld (hl), #C3 ;write JP\n inc l\n ld (hl), low(Interrupt_Handler)\n \n ;write interrupt handler address\n inc l\n ld (hl), high(Interrupt_Handler)\n \n im 2 ;set interrupt mode to 2\n ei ;enable interrupts\n\n ret<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"