Here is my version of the config file, if someone needs it:

#DS89C420
P0 SFR 080H
SP SFR 081H
DPL SFR 082H
DPH SFR 083H
DPL1 SFR 084H
DPH1 SFR 085H
DPS SFR 086H
PCON SFR 087H
TCON SFR 088H
TMOD SFR 089H
TL0 SFR 08AH
TL1 SFR 08BH
TH0 SFR 08CH
TH1 SFR 08DH
CKCON SFR 08EH

P1 SFR 090H
EXIF SFR 091H
CKMOD SFR 096H
SCON0 SFR 098H
SBUF0 SFR 099H
ACON SFR 09DH

P2 SFR 0A0H
IE SFR 0A8H
SADDR0 SFR 0A9H
SADDR1 SFR 0AAH

P3 SFR 0B0H
IP1 SFR 0B1H
IP0 SFR 0B8H
SADEN0 SFR 0B9H
SADEN1 SFR 0BAH

SCON1 SFR 0C0H
SBUF1 SFR 0C1H
ROMSIZE SFR 0C2H
BP2 SFR 0C3H
PMR SFR 0C4H
STATUS SFR 0C5H
TA SFR 0C7H
T2CON SFR 0C8H
T2MOD SFR 0C9H
RCAP2L SFR 0CAH
RCAP2H SFR 0CBH
TL2 SFR 0CCH
TH2 SFR 0CDH

PSW SFR 0D0H
FCNTL SFR 0D5H
FDATA SFR 0D6H
WDCON SFR 0D8H
BPA1 SFR 0DBH
BPA2 SFR 0DCH

ACC SFR 0E0H
EIE SFR 0E8H
B SFR 0F0H
EIP1 SFR 0F1H
EIP0 SFR 0F8H

IT0 BIT 088H
IE0 BIT 089H
IT1 BIT 08AH
IE1 BIT 08BH
TR0 BIT 08CH
TF0 BIT 08DH
TR1 BIT 08EH
TF1 BIT 08FH

T2 BIT 090H
T2EX BIT 091H
RXD1 BIT 092H
TXD1 BIT 093H
INT2 BIT 094H
INT3 BIT 095H
INT4 BIT 096H
INT5 BIT 097H

RI_0 BIT 098H
TI_0 BIT 099H
RB8_0 BIT 09AH
TB8_0 BIT 09BH
REN_0 BIT 09CH
SM2_0 BIT 09DH
SM1_0 BIT 09EH
SM0_0 BIT 09FH
FE_0 BIT 09FH

EX0 BIT 0A8H
ET0 BIT 0A9H
EX1 BIT 0AAH
ET1 BIT 0ABH
ES0 BIT 0ACH
ET2 BIT 0ADH
ES1 BIT 0AEH
EA BIT 0AFH

RXD0 BIT 0B0H
TXD0 BIT 0B1H
INT0 BIT 0B2H
INT1 BIT 0B3H
T0 BIT 0B4H
T1 BIT 0B5H
WR BIT 0B6H
RD BIT 0B7H

LPX0 BIT 0B8H
LPT0 BIT 0B9H
LPX1 BIT 0BAH
LPT1 BIT 0BBH
LPS0 BIT 0BCH
LPT2 BIT 0BDH
LPS1 BIT 0BEH

RI_1 BIT 0C0H
TI_1 BIT 0C1H
RB8_1 BIT 0C2H
TB8_1 BIT 0C3H
REN_1 BIT 0C4H
SM2_1 BIT 0C5H
SM1_1 BIT 0C6H
SM0_1 BIT 0C7H
FE_1 BIT 0C7H

CP_RL2 BIT 0C8H
C_T2 BIT 0C9H
TR2 BIT 0CAH
EXEN2 BIT 0CBH
TCLK BIT 0CCH
RCLK BIT 0CDH
EXF2 BIT 0CEH
TF2 BIT 0CFH

P BIT 0D0H
FL BIT 0D1H
F1 BIT 0D1H
OV BIT 0D2H
RS0 BIT 0D3H
RS1 BIT 0D4H
F0 BIT 0D5H
AC BIT 0D6H
CY BIT 0D7H

RWT BIT 0D8H
EWT BIT 0D9H
WTRF BIT 0DAH
WDIF BIT 0DBH
PFI BIT 0DCH
EPFI BIT 0DDH
POR BIT 0DEH
SMOD_1 BIT 0DFH

EX2 BIT 0E8H
EX3 BIT 0E9H
EX4 BIT 0EAH
EX5 BIT 0EBH
EWDI BIT 0ECH

LPX2 BIT 0F8H
LPX3 BIT 0F9H
LPX4 BIT 0FAH
LPX5 BIT 0FBH
LPWDI BIT 0FCH