Texas Instruments 990 Operation Manual page 260

~
945255-9701
Table G-3. Memory Configurations
Configuration in
PROM
Bit String Length
Initial Consecutive Strings
Type
Width
(Words) Bit
Across (A) or Down (D) Memory
MS287-O 4
256
0
D
MS287-4
4
256
4 D
MS287-8
4
256 8
D
MS287-C
4
256
C D
MS287A 4
64
0
A
MS288-O
8
32 0
D
MS288-8 8
32
8
D
MS288A
8
16 0
A
MS471-O 8
256
0
D
MS471-8
8 256
8
D
MS471A
8
128 0
A
MS472-O
8
512
0 D
MS472-8
8
512 8
D
MS472A 8
256
0
A
ME2704-O
8
512
0
D
ME2704-8 8
512 8
D
ME2704A 8
256
0
A
ME2708-0
8
1024
0
D
ME2708-8
8
1024
8 D
ME2708A
8
512
0
A
Note: TTL PROM types have the prefix SN74.
Table G-4. PROM Configurations
PROM
DDn ...
'l.A1 ___ ~
.I.
.n.Ulfl
"uru Length
Type Width
(Words)
S288
8
32
S287
4
256
S471 8
256
S472
8
512
E2704
8
512
E2708
8 1024
Note: TTL PROM types have the prefix SN74.
G-2
Digital Systems Division