Board Offset
($00/02) 7 6 5 4 3 2 1 0 Description of nibbles
R/W info \___ ___/ \___ ___/
\/ \/
Nibble at $E80000 Nibble at $E80002
Figure G-1: How to read the Address Specification Table
NOTE
The bit numbering ( 7 6 5 4 3 2 1 0 ) is for use when two nibbles are to
be interpreted together as a byte. Physically, each nibble is the high
nibble of the word at its address (i.e. bits 15 14 13 12).
Figure G-1: Address Specification Table
OFFSET: Address 1 Address 2 Description
-------------------------------------------------------------------------
($00/02) 7 6 5 4 3 2 1 0___Board size 000=8meg 100512k
Read | | | | | \__|__/ 001=64k 101=1meg
Not Inverted | | | | | 010=128k 110=2meg
| | | | | 011=256k 111=4meg
| | | | \-------- 1 = Next card is also on this board
| | | \----------- 1 = Optional ROM vector valid
| | \-------------- 1 = Link into memory free list (RAM)
| \____________
\______________>---- Board type 00 = Reserved
01 = Reserved
10 = Reserved
11 = Current type
($04/06) 7 6 5 4 3 2 1 0 Manufacturers chosen product
Read \___ ___/ \___ ___/ number
Inverted \/ \/
Hi nibble Lo nibble
($08/0A) 7 6 5 4 3 2 1 0 (Remember - these read inverted)
Read | | |_|_|_|_|_|_ Reserved - Should be 0 currently
Inverted | |
| \____________\ 0 = this board can be shut-up
| / 1 = this board ignores shut-up
|
\______________\ 0 = any space OK
/ 1 = 8 Meg area preferred
- 338 Appendix G -
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