Compaq Portable 286 Compaq Portable Computer, Compaq Plus Personal Computer, a - Page 34

Table 5.4-1. Defective Memory Chip Isolation Map for the COMPAQ PORTABLE 286

Get Compaq Portable 286 - Notebook PC PDF manuals and user guides View all Compaq Portable 286 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 34 highlights

The memory error code points to a specific memory address. The physical location of the memory address depends on the type of system, the number and type of memory boards installed, and the type of memory device used (64 Kbyte RAMs or 256 Kbyte RAMs). COMPAQ PORTABLE 286 Memory Error Codes Memory error codes are in the XX000B YYZZ format. o XX equals the 128 Kbyte memory segment (bank) in which an error is detected. o 000 is always equal to 000 (not used) o B identifies whether the defective memory chip is in the high byte or the low byte of the memory bank. o When B = 0, YY defines the defective chip row location within the low byte of the memory bank. o When B = 1, ZZ defines the defective chip row location within the high byte of the memory bank. For example, assume error code 020001 0010 appears on the monitor. First determine which table to reference (see COMPAQ PORTABLE 286 Memory Configuration). Next, determine which bank to reference and which byte, high or low. Finally, determine the defective chip row location. In this example, error code 020001 0010 specifies chip U50 in Table 5.4-1. Use the following charts to locate a defective memory chip: COMPAQ PORTABLE 286 Memory Configuration RAM Type Error Code Memory See xx Value Device Location Table 64 Kbyte 00 to 02 (0 - 256 Kbytes) System Board 5.4-1 256 Kbyte 00 to 08 (0 - 640 Kbytes) System Board 5.4-2 64 Kbyte or 256 Kbyte 10 to 2E (1 - 3 megabytes) Memory Expansion Board 5.4-3 NOTE: xx codes 0A to 0F represent the memory space for the video memory and system ROMs. Errors in the video memory or system ROM space are not reported in the XX000B YYZZ error message format. Table 5.4-1. Defective Memory Chip Isolation Map for the COMPAQ PORTABLE 286 System Board Using 64 Kbyte RAMs (0 - 256 Kbytes) XX = 00 XX = 02 Bank 0 Bank 1 Data Bit B=0 B=1 B=0 B=1 YY or ZZ Low High Low High

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
The memory error code points to a specific memory address. The physical
location of the memory address depends on the type of system, the number and
type of memory boards installed, and the type of memory device used (64 Kbyte
RAMs or 256 Kbyte RAMs).
COMPAQ PORTABLE 286 Memory Error Codes
Memory error codes are in the XX000B YYZZ format.
o XX equals the 128 Kbyte memory segment (bank) in which an error is
detected.
o 000 is always equal to 000 (not used)
o B identifies whether the defective memory chip is in the high byte or the
low byte of the memory bank.
o When B = 0, YY defines the defective chip row location within the low byte
of the memory bank.
o When B = 1, ZZ defines the defective chip row location within the high byte
of the memory bank.
For example, assume error code 020001 0010 appears on the monitor. First
determine which table to reference (see COMPAQ PORTABLE 286 Memory
Configuration). Next, determine which bank to reference and which byte, high
or low. Finally, determine the defective chip row location. In this example,
error code 020001 0010 specifies chip U50 in Table 5.4-1. Use the following
charts to locate a defective memory chip:
COMPAQ PORTABLE 286 Memory Configuration
==============================================================================
RAM Type
Error Code
Memory
See
xx Value
Device Location
Table
------------------------------------------------------------------------------
64 Kbyte
00 to 02 (0 - 256 Kbytes)
System Board
5.4-1
256 Kbyte
00 to 08 (0 - 640 Kbytes)
System Board
5.4-2
64 Kbyte or
256 Kbyte
10 to 2E (1 - 3 megabytes) Memory Expansion Board
5.4-3
------------------------------------------------------------------------------
NOTE: xx codes 0A to 0F represent the memory space for the video memory and
system ROMs. Errors in the video memory or system ROM space are not reported
in the XX000B YYZZ error message format.
==============================================================================
Table 5.4-1. Defective Memory Chip Isolation Map for the COMPAQ PORTABLE 286
System Board Using 64 Kbyte RAMs (0 - 256 Kbytes)
==============================================================================
XX = 00
XX = 02
Bank 0
Bank 1
------------------------------------------------------------------------------
Data Bit
B=0
B=1
B=0
B=1
YY or ZZ
Low
High
Low
High
------------------------------------------------------------------------------