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Kingsoft 4-Player Adapter Specs v0.1 last changes: 14.03.2012
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Supports 2 additional joysticks at the userport.
Introduced with the game Bug Bomber by Kingsoft in 1992, the game came with
instructions to build your own 4-player adapter.
Note: although the adapter uses the same idea as the Starbyte and DXS/HIT
adapters, it is NOT compatible with them!
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WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
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The "schematics" shown in the bug bomber manual is wrong
(http://www.synnes.org/c64/images/kingsoft_4_player_adapter_schematics.png)
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WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
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Schematics:
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GND 1 ---------------+--- 8 JOY 3 GND
CNT1 4 ->-+ +--- 8 JOY 4 GND
CNT2 6 -<-+
SP2 7 ----------<-------- 6 JOY 4 BUTTON
PB0 C ----------<-------- 4 JOY 4 A3
PB1 D ----------<-------- 3 JOY 4 A2
PB2 E ----------<-------- 2 JOY 4 A1
PB3 F ----------<-------- 1 JOY 4 A0
PB4 H ----------<-------- 6 JOY 3 BUTTON
PB5 J ----------<-------- 4 JOY 3 A3
PB6 K ----------<-------- 3 JOY 3 A2
PB7 L ----------<-------- 2 JOY 3 A1
PA2 M ----------<-------- 1 JOY 3 A0
note: all GND pins at the userport (1, 12, A, N) should be connected to each
other.
Example code (from "Bug Bomber"):
--------------------------------
; joystick 3
; set port A bit 2
.C:933d 78 SEI
.C:933e AD 00 DD LDA $DD00
.C:9341 09 04 ORA #$04
.C:9343 8D 00 DD STA $DD00
.C:9346 58 CLI
; check port A bit 2
.C:9347 AD 00 DD LDA $DD00
.C:934a 29 04 AND #$04
.C:934c D0 06 BNE $9354
; clear joy bit 0
.C:934e A5 43 LDA $43
.C:9350 29 FE AND #$FE
.C:9352 85 43 STA $43
; check port B bit 7
.C:9354 AD 01 DD LDA $DD01
.C:9357 29 80 AND #$80
.C:9359 D0 06 BNE $9361
; clear joy bit 1
.C:935b A5 43 LDA $43
.C:935d 29 FD AND #$FD
.C:935f 85 43 STA $43
; check port B bit 6
.C:9361 AD 01 DD LDA $DD01
.C:9364 29 40 AND #$40
.C:9366 D0 06 BNE $936E
; clear joy bit 2
.C:9368 A5 43 LDA $43
.C:936a 29 FB AND #$FB
.C:936c 85 43 STA $43
; check port B bit 5
.C:936e AD 01 DD LDA $DD01
.C:9371 29 20 AND #$20
.C:9373 D0 06 BNE $937B
; clear joy bit 3
.C:9375 A5 43 LDA $43
.C:9377 29 F7 AND #$F7
.C:9379 85 43 STA $43
; check port B bit 4
.C:937b AD 01 DD LDA $DD01
.C:937e 29 10 AND #$10
.C:9380 D0 44 BNE $93C6
; clear joy bit 4
.C:9382 A5 43 LDA $43
.C:9384 29 EF AND #$EF
.C:9386 85 43 STA $43
.C:9388 60 RTS
; joystick 4
; get 4 lower bits from port B
; to joy bits 0..3 in reverse order
.C:9389 AD 01 DD LDA $DD01
.C:938c 4A LSR A
.C:938d 26 44 ROL $44
.C:938f 4A LSR A
.C:9390 26 44 ROL $44
.C:9392 4A LSR A
.C:9393 26 44 ROL $44
.C:9395 4A LSR A
.C:9396 26 44 ROL $44
.C:9398 A9 3F LDA #$3F
.C:939a 8D 02 DD STA $DD02
.C:939d A9 00 LDA #$00
.C:939f 8D 03 DD STA $DD03
.C:93a2 AD 0E DC LDA $DC0E
.C:93a5 29 F7 AND #$F7
.C:93a7 09 40 ORA #$40
.C:93a9 8D 0E DC STA $DC0E
.C:93ac AD 0E DD LDA $DD0E
.C:93af 29 BF AND #$BF
.C:93b1 8D 0E DD STA $DD0E
.C:93b4 A9 00 LDA #$00
.C:93b6 8D 0C DC STA $DC0C
; get fire from cia2 synchronous serial (SP2)
.C:93b9 AD 0C DD LDA $DD0C
.C:93bc C9 FF CMP #$FF
.C:93be F0 06 BEQ $93C6
; clear joy bit 4 (button)
.C:93c0 A5 44 LDA $44
.C:93c2 29 EF AND #$EF
.C:93c4 85 44 STA $44
.C:93c6 60 RTS
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credits:
--------
reverse enginering, this document : Groepaz/Hitmen (groepaz@gmx.net)