Apple ii Battery Charger User Manual


 
F796: 20 19 F7 181 JSR STAT2 ;PUSH LOW PC BYTE VIA R12
F799: A5 1F 182 LDA R15H
F79B: 20 19 F7 183 JSR STAT2 ;PUSH HIGH-ORDER PC BYTE
F79E: 18 184 BR CLC
F79F: B0 0E 185 BNC BCS BNC2 ;NO CARRY TEST
F7A1: B1 1E 186 BR1 LDA (R15L),Y ;DISPLACEMENT BYTE
F7A3: 10 01 187 BPL BR2
F7A5: 88 188 DEY
F7A6: 65 1E 189 BR2 ADC R15L ;ADD TO PC
F7A8: 85 1E 190 STA R15L
F7AA: 98 191 TYA
F7AB: 65 1F 192 ADC R15H
F7AD: 85 1F 193 STA R15H
F7AF: 60 194 BNC2 RTS
F7B0: B0 EC 195 BC BCS BR
F7B2: 60 196 RTS
F7B3: 0A 197 BP ASL ;DOUBLE RESULT-REG INDEX
F7B4: AA 198 TAX ;TO X REG FOR INDEXING
F7B5: B5 01 199 LDA R0H,X ;TEST FOR PLUS
F7B7: 10 E8 200 BPL BR1 ;BRANCH IF SO
F7B9: 60 201 RTS
F7BA: 0A 202 BM ASL ;DOUBLE RESULT-REG INDEX
F7BB: AA 203 TAX
F7BC: B5 01 204 LDA R0H,X ;TEST FOR MINUS
F7BE: 30 E1 205 BMI BR1
F7C0: 60 206 RTS
F7C1: 0A 207 BZ ASL ;DOUBLE RESULT-REG INDEX
F7C2: AA 208 TAX
F7C3: B5 00 209 LDA R0L,X ;TEST FOR ZERO
F7C5: 15 01 210 ORA R0H,X ;(BOTH BYTES)
F7C7: F0 D8 211 BEQ BR1 ;BRANCH IF SO
F7C9: 60 212 RTS
F7CA: 0A 213 BNZ ASL ;DOUBLE RESULT-REG INDEX
F7CB: AA 214 TAX
F7CC: B5 00 215 LDA R0L,X ;TEST FOR NON-ZERO
F7CE: 15 01 216 ORA R0H,X ;(BOTH BYTES)
F7D0: D0 CF 217 BNE BR1 ;BRANCH IF SO
F7D2: 60 218 RTS
F7D3: 0A 219 BM1 ASL ;DOUBLE RESULT-REG INDEX
F7D4: AA 220 TAX
F7D5: B5 00 221 LDA R0L,X ;CHECK BOTH BYTES
F7D7: 35 01 222 AND R0H,X ;FOR $FF (MINUS 1)
F7D9: 49 FF 223 EOR #$FF
F7DB: F0 C4 224 BEQ BR1 ;BRANCH IF SO
F7DD: 60 225 RTS
F7DE: 0A 226 BNM1 ASL ;DOUBLE RESULT-REG INDEX
F7DF: AA 227 TAX
F7E0: B5 00 228 LDA R0L,X
F7E2: 35 01 229 AND R0H,X ;CHECK BOTH BYTES FOR NO $FF
F7E4: 49 FF 230 EOR #$FF
F7E6: D0 B9 231 BNE BR1 ;BRANCH IF NOT MINUS 1
F7E8: 60 232 NUL RTS
F7E9: A2 18 233 RS LDX #$18 ;12*2 FOR R12 AS STACK POINTER
F7EB: 20 66 F7 234 JSR DCR ;DECR STACK POINTER
F7EE: A1 00 235 LDA (R0L,X) ;POP HIGH RETURN ADDRESS TO PC
F7F0: 85 1F 236 STA R15H
F7F2: 20 66 F7 237 JSR DCR ;SAME FOR LOW-ORDER BYTE
F7F5: A1 00 238 LDA (R0L,X)
F7F7: 85 1E 239 STA R15L
F7F9: 60 240 RTS
F7FA: 4C C7 F6 241 RTN JMP RTNZ