21xx 486SX-33 MHz (72-Pin SIMM)
J1 Keyboard
J2 Mouse
J3 Serial Port A
J4 Serial Port B
J5 Parallel Port
J6 Display
J7 Diskette
J8 Power
J9 Hard Disk Drive
J11 Riser
J14 VESA Video feature connector
J15 Video Disable
norm. operation Pin 1-2
J16 Cache Jumper
J17 Cache Jumper
J16 and J17 must be Pin 2-3
for upgrade to 256K
J19 RAM 72-Pin Memory - Bank 3
J20 RAM 72-Pin Memory - Bank 2
J21 RAM 72-Pin Memory - Bank 1
J22 RAM 72-Pin Memory - Bank 0
Sockets can be populated in any
order
J23 Processor-type Jumper
J24 Processor-type Jumper
J25 Processor-type Jumper
J26 LED Connector Power Pin 1-2
Hard Disk Drive Pin 3-4
J27 Speaker Volume Control (WT only)
SP103 Password Bypass
SP193 Beeper Enable
U7 System ROM
U19 Cache Memory Address Module
for 128K/256K Cache
U28 Cache Memory Socket Bank 1
U29 Cache Memory Socket Bank 1
U30 Cache Memory Socket Bank 1
U31 Cache Memory Socket Bank 1
U37 Cache Memory Socket Bank 2
U38 Cache Memory Socket Bank 2
U43 Cache Memory Socket Bank 2
U44 Cache Memory Socket Bank 2
U45 486DX, 486 Math, 486DX2
486 Overdrive or Pentium®
ODP Processor
U46 486SX Processor
Please see the LEGAL - Trademark notice.
Feel free - send a 
for any BUG on this page found - Thank you.