Specifications

01 U5 U6 U7 U8
02 U20 U21 U22 U23
04 U25 U26 U27 U28
08 U41 U42 U43 U44
10 U47 U48 U49 U50
20 U63 U64 U65 U66
40 U70 U71 U72 U73
80 U81 U82 U83 U84
00 U88 U89 U90 U91
==============================================================================
Table 5.4-2. Defective Memory Chip Isolation Map for the COMPAQ PORTABLE 286
System Board Using 256 Kbyte RAMs (0 - 640 Kbytes)
==============================================================================
XX=02
XX = 00 06, 08
Bank 0 Bank 1
------------------------------------------------------------------------------
Data Bit B = 0 B = 1 B = 0 B = 1
YY or ZZ Low High Low High
------------------------------------------------------------------------------
01 U5 U6 U7 U8
02 U20 U21 U22 U23
04 U25 U26 U27 U28
08 U41 U42 U43 U44
10 U47 U48 U49 U50
20 U63 U64 U65 U66
40 U70 U71 U72 U73
80 U81 U82 U83 U84
00 U88 U89 U90 U91
==============================================================================
Table 5.4-3. Defective Memory Chip Isolation Map for a Memory Expansion Board
Mapped into the 1 - 3 Megabyte Memory Space (256 Kbyte RAMs)
==============================================================================
XX = 10, 12, XX = 18, 1A, XX = 20, 22, XX = 28, 2A,
14, 16 1C, 1E 24, 26 2C, 2E
Bank 1 Bank 2 Bank 3 Bank 4
------------------------------------------------------------------------------
Data Bit B = 1 B = 0 B = 1 B = 0 B = 1 B = 0 B = 1 B = 0
YY or ZZ High Low High Low High Low High Low
------------------------------------------------------------------------------
80 U3 U12 U21 U30 U39 U48 U57 U66