History
- Released
- 23 May 1987
- Code
- Unknown (likely Dr.J or Mog)
- Music
- None
- Graphics
- Unknown
- Group
- Scouse Cracking Group — Liverpool, UK, founded July 1986
Liverpool's Scouse Cracking Group delivered one of the most visually striking British intros of 1987: a large custom-charset logo flanked by animated rasterbars that appear to pass both in front of and behind the lettering — an illusion achieved by precise IRQ-timed writes to $D020 and $D021 interleaved with the logo's character rows. A stabilized single-IRQ routine using a double $D012 compare keeps the bars locked across 28 crack releases, making this one of the most-used UK intros of its year. SCG was voted fourth-best cracker group in Illegal magazine issue #19 (August 1987), and this intro was their calling card at the height of that recognition.
Sources: CSDb · CSDb group · Demozoo
scg-04.asm 1.420 lines
// ============================================ // scg-04 - Part 1 of 2 // ============================================ // KickAssembler syntax // Generated by Restore 64 vdisasm-one 1.0 build 1, 2026-03-29 17:54:23 // 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: $1000 (4096) // IRQ handler: $106d (irq_106d) // // Code: 1132 bytes, Data: 62356 bytes // Labels: 148, Subroutines: 10 // // Cross-references: all OK // ============================================ // --- Region $0814-$0851 --- .pc = $0814 "sub_0814" // Referenced by: jsr from $ffd9 sub_0814: sbc #$eb nop nop .byte $3f,$fa,$ea // rla $eafa,x // ILLEGAL nop nop sbc #$e9 sbc #$ff nop nop nop sbc #$e9 sbc #$e9 .byte $3f,$fa,$ea // rla $eafa,x // ILLEGAL nop sbc #$eb nop nop .byte $3f,$fa,$ea // rla $eafa,x // ILLEGAL nop sbc #$eb nop nop .byte $3f,$fa,$ea // rla $eafa,x // ILLEGAL nop nop sbc #$e9 sbc #$fd sbc #$e9 sbc #$e9 sbc #$ea nop .byte $0f,$0e,$0e // slo $0e0e // ILLEGAL asl $0e0e asl.abs $000e brk // --- Region $09db-$09e0 --- .pc = $09db "loc_09db" loc_09db: brk dat_09dc: .byte $00 // . loc_09dd: brk dat_09de: .byte $00 // . loc_09df: brk loc_09e0: brk // --- Region $0a2c-$0a61 --- .pc = $0a2c "Program $0a2c" eor $fd,x lda #$a9 sbc $a9a9,x lda #$55 sbc $a9a9,x sbc $a9a9,x lda #$55 sbc $a9a9,x sbc $e9e9,x sbc #$e9 sbc #$a9 lda #$d0 bcc loc_09db bcc loc_09dd .label loc_0a4e = * + 1 bcc loc_09df bcc loc_0a4e sbc #$e9 sbc #$e9 sbc #$e9 sbc #$fd sbc #$e9 sbc #$e9 lda #$a5 sty $00,x brk // --- Region $0e0f-$0e17 --- .pc = $0e0f "sub_0e0f" // Referenced by: jsr from $1410 sub_0e0f: brk dat_0e10: .byte $a9,$69,$e9,$a9,$a9 // .i... lda $54 brk // --- Region $0f03-$0f03 --- .pc = $0f03 "Program $0f03" brk // --- Region $0f14-$0f14 --- .pc = $0f14 "sub_0f14" // Referenced by: jsr from $142e sub_0f14: brk // --- Region $1000-$119a --- .pc = $1000 "main_1000" main_1000: sei lda #$08 jsr $ffd2 lda #$93 jsr $ffd2 lda #$0b sta $d022 lda #$0c sta $d024 lda #$12 sta $d018 // screen=$0400, charset=$0800