MCS-51

AMD

 D8031AH
 
12 MHz
40 pin CERDIP
IP8031AH
 
12 MHz
40 pin PDIP
P8031AH
 
12 MHz
40 pin PDIP
N80C31BH
 12 MHz
4w pin PLCC
P8051AH-40196
 
12 MHz
40 pin PDIP
AMD8751H
 
12 MHz
40 pin PDIP
D87C521-1
 
12 MHz
40 pin CDIP

ATMEL

 80C31X2-UL
 
MHz
40 pin PDIP
 80C32X2-UM
 
MHz
40 pin PDIP

Dallas Semiconductor

 DS80C320
 
MHz
44 pin PLCC

INTEL

D8031AH
 
12 MHz
40 pin CERDIP
LD8031
 
12 MHz
40 pin CERDIP
N8031AH
12 MHz
44 pin PLCC
N80C31BH
? MHz
44 pin PLCC
P8031AH
 
12 MHz
40 pin PDIP
P80C31BH
 
12 MHz
40 pin PDIP
LD8031AH
 
12 MHz
40 pin CERDIP
TN80C31BH
12 MHz
44 pin PLCC
TP80C31BH
 
12 MHz
40 pin PDIP
P80C32
 
MHz
40 pin PDIP
P8032AH
 
12 MHz
40 pin PDIP
TP80C32
 
12 MHz
40 pin PDIP
MR80C51BH/B
 
12 MHz
40 pin PDIP
D8051
 
12 MHz
40 pin CERDIP
D8051AH
 
12 MHz
40 pin CERDIP
P8051
 
12 MHz
40 pin PDIP
P8051AH
 
12 MHz
40 pin PDIP
P80C51BH
 
12 MHz
40 pin PDIP
N80C51FC  Q8221
 
12 MHz
44 pin PLCC
Sample
TD87C51
 
12 MHz
40 pin CERDIP
TN80C51FA1
 
12 MHz
44 pin PLCC
P80A52AH
 
12 MHz
40 pin PDIP
LN80C152JB
 
12 MHz
68 pin PLCC
C8751
 
12 MHz
40 pin CERDIP
C8751-8
 
?MHz
40 pin CERDIP
C8751H
 
12 MHz
40 pin CERDIP
C8751H-8
 
12 MHz
40 pin CERDIP
C8751H-88
 
12 MHz
40 pin CERDIP
C8751H-12
 
12 MHz
40 pin CERDIP
QC8751H
 
12 MHz
40 pin CERDIP
D8751H
 
12 MHz
40 pin CERDIP
R8751H
 
12 MHz
44 pin CLCC
P87C51-1
 
12 MHz
40 pin PDIP

MHS

P-80C31
 
MHz
40 pin PDIP
P-80C31-12
 
MHz
40 pin PDIP
P-80C31AH
 
MHz
40 pin PDIP
P-80C31-V
 
MHz
40 pin PDIP
S-80C31
12 MHz
44 pin PLCC
P-8032AH
 
 MHz
40 pin PDIP
P-80C32
 
 MHz
40 pin PDIP
Q-80C52683
12 MHz
44 pin CLCC

OKI

M80C31F
 
12 MHz
40 pin PDIP
M80C31F
12 MHz
44 pin PLCC
M80C51
 
12 MHz
40 pin CDIP
M85C154
 
12 MHz
40 pin CDIP

Philips

MAB 8031AH 15P
 
MHz
40 pin PDIP
MAB 8031AH-2 12P
 
MHz
40 pin PDIP
PC80C31BH-3-16P
 
MHz
40 pin PDIP
PCB80C31BH-4 24WP
12 MHz
44 pin PLCC
PCF80C31-3-12WP
12 MHz
44 pin PLCC
MAB8051AH
 
MHz
40 pin PDIP
SC80C51BCCN40
 
MHz
40 pin PDIP
P87C52UBPN
 
33 MHz
40 pin PDIP
low voltage 2.7V.5.5V, low power, high speed 33 MHz
P89C51RD+JB
12 MHz
PQFP 44

Russian

KP1816BE31
 
 MHz
40 pin PDIP
Intel 8031AH clone
Manufactured by Electronica
KP1816BE51
 
 MHz
40 pin PDIP
Intel 8051AH clone
Manufactured by Electronica
KP1830BE31
 
 MHz
40 pin PDIP
Intel 80C31 clone
Manufactured by Electronica

TEMIC

TS80C31-12CA
 
MHz
40 pin PDIP
P-80C52CQR-12
 
MHz
40 pin PDIP

SIEMENS

SAB8031P T40-85
 
MHz
40 pin PDIP
SAB8032A-16-P
 
MHz
40 pin PDIP
SAB83C515AH-5J
 
MHz
68 pin CLCC

SIGNETICS

SCN8031HCCN40
 
MHz
40 pin PDIP
SCN8032HCCN40
 
MHz
40 pin PDIP
P80C32IBAA
 MHz
44 pin PLCC
SCN8051HCCN40
 
MHz
40 pin PDIP

Windbond

W78C32B-24
 
MHz
40 pin PDIP
Compatible with 80C32
W78C32C-24
 
MHz
40 pin PDIP
Compatible with 80C32