Decibel [DBL] 03

Decibel [DBL]

1.023 lines of code

ScrollerSCRLBitmapBMAP

History

Released
July 1987
Code
Unknown
Music
None
Graphics
Unknown
Group
Decibel — Netherlands, founded 1987

Decibel were a prolific Dutch cracking group active throughout 1987, producing nine numbered crack intros in rapid succession. Intro 03 stands out for its clean bitmap logo presentation and text scroller — and notably for its absence of SID music, an unusual choice at a time when ripped Rob Hubbard tunes were the norm. Despite lacking music, the intro saw wide distribution, being attached to at least 18 different Decibel cracks including Mars Patrol Preview +, Stationfall, Game Over +2, and Deadringer +.

Sources: CSDb · CSDb group

dbl-03.asm 1.023 lines
// ============================================
// dbl-03 - Disassembled Source
// ============================================
// KickAssembler syntax
// Generated by Restore 64 vdisasm-one 1.0 build 1, 2026-03-29 17:54:16
// https://restore64.dev by datucker / Rabenauge
//
// Load address: $0800  End: $ffff  (63488 bytes)
// Crunched with Exomizer v2/v3 (with relocation) — depacked by emulation
// Packer entry: $0810 (via BASIC SYS 2064)
// Entry point:  $1450 (5200)
// IRQ handler:  $ea31 (irq_ea31)
//
// Code: 256 bytes, Data: 63232 bytes
// Labels: 110, Subroutines: 1
//
// Cross-references: all OK
// ============================================


// --- Region $0b80-$0c02 ---
.pc = $0b80 "loc_0b80"

loc_0b80:
        ldx #$00

loc_0b82:
        lda $0ff0,x
        sta $d000,x
        inx
        cpx #$2f
        bne loc_0b82
        ldx #$28
        stx $07f8
        inx
        stx $07f9
        inx
        stx $07fa
        inx
        stx $07fb
        inx
        stx $07fc
        dex
        dex
        dex
        stx $07fd
        ldx #$2d
        stx $07fe
        lda #$01
        sta $d019                                   // raster // acknowledge raster IRQ
        sta.abs $00fb
        lda #$05
        sta $dc05
        lda #$a0
        ldy #$0f
        jsr sub_ab1e
        lda #$40
        sta $d010
        sei
        lda #$10
        ldx #$20
        stx $0314
        sta $0315                                   // set IRQ handler high byte
        cli

loc_0bd2:
        jsr $ffe4
        cmp #$20
        bne loc_0bd2

loc_0bd9:
        lda $dc01
        cmp #$ef
        bne loc_0bd9
        sei
        jsr $fda3
        lda #$31
        sta $0314                                   // set IRQ handler low byte
        lda #$ea
        sta $0315                                   // set IRQ handler high byte
        cli
        jsr $e518
        ldy #$00

loc_0bf4:
        lda chr_0c02,y
        sta $033c,y
        iny
        cpy #$2c
        bne loc_0bf4
        jmp $033c

chr_0c02:
        // === Charset data (1 bytes, $0c02-$0c02) ===
        .byte $a9                                   // char 0 (partial)

// --- Region $106e-$1076 ---
.pc = $106e "Segment $106e"
        php
        ora ($12,x)
        .byte $14,$2d                               // nop $2d,x // ILLEGAL
        .byte $0c,$09,$13                           // nop $1309 // ILLEGAL

txt_1076:
        .encoding "screencode_mixed"
        .text "t"
        .encoding "petscii_upper"

// --- Region $1450-$1467 ---
.pc = $1450 "main_1450"

main_1450:
        lda #$60
        sta $0c75
        lda #$10
        sta $0c76
        lda #$12
        sta $0d06
        lda #$c0
        sta $0d05
        jmp loc_0b80

dat_1467:
        // === Fill data (1 bytes, $1467-$1467) ===
        .byte $00                                   // .

// --- Region $148e-$148e ---
.pc = $148e "Segment $148e"
        brk

// --- Region $3f80-$3f80 ---
.pc = $3f80 "loc_3f80"

loc_3f80:
        brk

// --- Region $ab1e-$ab1e ---
.pc = $ab1e "sub_ab1e"
// Referenced by: jsr from $0bbe

sub_ab1e:
        brk

// --- Region $e518-$e518 ---
.pc = $e518 "Segment $e518"
        brk

// --- Region $ea31-$ea31 ---
.pc = $ea31 "irq_ea31"