Just updating this post with the full pinout and physical measurements in case this helps anyone in the future who needs to make one of these or something...
SIMM pins (left to right):
Pinouts of each PLCC chip:
Size:
Dimensions are pretty much the same as my 8 MB ROM SIMM (see the EAGLE file at http://code.google.com/p/mac-rom-simm-programmer/), except there's a cutout in the upper left corner. The cutout begins 81.5 mm from the right side of the SIMM, and it begins 13.6 mm from the bottom of the SIMM.
Other notes:
It's exactly the same as the earlier SE/30 and II series ROM SIMM pinout, but with these exceptions:
Chip markings are as follows:
U1 = 341S1078
U2 = 341S1079
U3 = 341S1080
U4 = 341S1081
Sticker on SIMM says 341-0675
PCB silkscreen says 820-0482-A
APPLE COMPUTER INC.
PCB, 2 MEG SIMM © 1993
SIMM pins (left to right):
Code:
1 - VCC (+5V)
2 - not connected (A0)
3 - not connected (A1)
4 - A2 (connected to all chips' A0)
5 - A3 (connected to all chips' A1)
6 - A4 (connected to all chips' A2)
7 - A5 (connected to all chips' A3)
8 - A6 (connected to all chips' A4)
9 - A7 (connected to all chips' A5)
10 - GND
11 - VCC (+5V)
12 - !OE (connected to all chips' !OE)
13 - VCC (+5V)
14 - D0 (connected to UI's D0)
15 - D1 (connected to UI's D1)
16 - D2 (connected to UI's D2)
17 - D3 (connected to UI's D3)
18 - D4 (connected to UI's D4)
19 - D5 (connected to UI's D5)
20 - D6 (connected to UI's D6)
21 - D7 (connected to UI's D7)
22 - D8 (connected to U2's D0)
23 - D9 (connected to U2's D1)
24 - D10 (connected to U2's D2)
25 - D11 (connected to U2's D3)
26 - D12 (connected to U2's D4)
27 - D13 (connected to U2's D5)
28 - D14 (connected to U2's D6)
29 - D15 (connected to U2's D7)
30 - GND
31 - A8 (connected to all chips' A6)
32 - A9 (connected to all chips' A7)
33 - A10 (connected to all chips' A8)
34 - A11 (connected to all chips' A9)
35 - A12 (connected to all chips' A10)
36 - A13 (connected to all chips' A11)
37 - A14 (connected to all chips' A12)
38 - A15 (connected to all chips' A13)
39 - A16 (connected to all chips' A14)
40 - A17 (connected to all chips' A15)
41 - A18 (connected to all chips' A16)
42 - A19 (connected to all chips' A17)
43 - A20 (connected to all chips' A18)
44 - not connected (probably reserved as A21)
45 - not connected (probably reserved as A22)
46 - VCC (+5V)
47 - D16 (connected to U3's D0)
48 - D17 (connected to U3's D1)
49 - D18 (connected to U3's D2)
50 - D19 (connected to U3's D3)
51 - D20 (connected to U3's D4)
52 - D21 (connected to U3's D5)
53 - D22 (connected to U3's D6)
54 - D23 (connected to U3's D7)
55 - D24 (connected to U4's D0)
56 - D25 (connected to U4's D1)
57 - D26 (connected to U4's D2)
58 - D27 (connected to U4's D3)
59 - D28 (connected to U4's D4)
60 - D29 (connected to U4's D5)
61 - D30 (connected to U4's D6)
62 - D31 (connected to U4's D7)
63 - VCC (+5V)
64 - GND
Code:
1 - labeled as A18 by JEDEC, but it's connected to VCC on the SIMM -- possibly !WE on earlier standard
2 - A16
3 - A15
4 - A12
5 - A7
6 - A6
7 - A5
8 - A4
9 - A3
10 - A2
11 - A1
12 - A0
13 - D0
14 - D1
15 - D2
16 - GND
17 - D3
18 - D4
19 - D5
20 - D6
21 - D7
22 - labeled as "!CE" by JEDEC. SIMM connects it directly to GND so it's always active.
23 - A10
24 - !OE
25 - A11
26 - A9
27 - A8
28 - A13
29 - A14
30 - A17
31 - labeled as !WE by JEDEC, but it appears to be used as A18 on the ROM chips. maybe different standard.
32 - VCC (+5V)Dimensions are pretty much the same as my 8 MB ROM SIMM (see the EAGLE file at http://code.google.com/p/mac-rom-simm-programmer/), except there's a cutout in the upper left corner. The cutout begins 81.5 mm from the right side of the SIMM, and it begins 13.6 mm from the bottom of the SIMM.
Other notes:
It's exactly the same as the earlier SE/30 and II series ROM SIMM pinout, but with these exceptions:
- The chips don't pay attention to the older pinout's !CE pin -- the chip enable pins on the four chips are wired to ground so chip enable is always active.
- The older pinout's !CE pin is wired directly to +5V.
Chip markings are as follows:
U1 = 341S1078
U2 = 341S1079
U3 = 341S1080
U4 = 341S1081
Sticker on SIMM says 341-0675
PCB silkscreen says 820-0482-A
APPLE COMPUTER INC.
PCB, 2 MEG SIMM © 1993