8580 Planar Memory

IBM Planar Memory Cards
8580 Planar Memory Sizes
   8580 System Support of Planar Memory Sizes
Planar Memory Pinout
   Presence Detection
   Pinout Comparison with 72-pin SIMMs


IBM Planar Memory Cards

Note: There are a few different layouts on the 1 MB size.


8580 Planar Memory Sizes

System Board 16 MHz (8580-041, 071) 33F8416
1 MB 80 ns Memory Kit (for 33F8416) 72X6670 or 6450375

72X7475 found

System Board 20 MHz 10G4148 (8580-081, 111, 121, 161, 311, 321)
2 MB 80 ns Memory Kit (for 92F0756) 92F0669 or 6450379

92F0669 found. 90X7391 in Jan 1992 Pocket Ref Manual.

System Board 25 MHz 85F0046 (8580-A21, A31, A61)
4 MB 80 ns Memory Kit (for 85F0046) 92F0106 or 6451060

33F5498? 34F0023 in Jan 1992 Pocket Ref Manual.

8580 System Support of Planar Memory Sizes (From Fred Spencer, original HERE)

On the initial 8580 models, only 1 MB and 2 MB planar memory modules were available. With the announcement of the 25MHz planars (8580-Axx), 4 MB memory cards became available. However, it has been discovered that they will function on the 20 MHz planars (thanks to Tim Clarke and Joe Kovacs for this discovery). A summary table of my experiences using various sizes of memory cards in each of the three categories of planars follows:

Size16 MHz20 MHz25 MHz
1 MBOKOK225
2 MBOKOK225
4 MB2 MBOKOK

Note 1: 16 MB planar can use 4 MB card, but can only use 2 MB. [ed.]

Note 2: 225 is the POST Error Code resulting from having memory that is too slow.

Note 3: On some 20 MHz planars with 4 MB memory cards on the planar, the IBM diagnostics will occasionally fail, but the memory will still function OK. With the PIICEON 4 MB (70 ns) memory card the IBM diagnostics may also fail. However, both the IBM and PIICEON 4 MB memory cards will function properly and they do pass the Norton Utilities memory diagnostics without any problems. I will be doing more investigation regarding this.


Planar Memory Pinout

The Type 1, 2, and 3 system boards are equipped with two 3- by 32-pin system board memory connectors. A memory card must be installed in connector 1 before additional memory can be used in the channel.

The following figure shows the pin locations of the 3- by 32-pin system board memory connectors. The pin locations are the same for connectors 1 and 2. Connector 1 is closest to the power supply. Pin 32 is closest to the rear of the system board.

Row ARow BRow C
PinI/OSignalPinI/OSignalPinI/OSignal
A1N/AReservedB1NAGroundC1I/OMDO
A2I-MWB2NA+5 VdcC2I/OMD1
A3IMA0B3NAGroundC3I/OMD2
A4IMA1B4NA+5 VdcC4I/OMD3
A5IMA2B5NAGroundC5I/OMD4
A6IMA3B6NA+5 VdcC6I/OMD5
A7IMA4B7NAGroundC7I/OMD6
ASIMA5B8NA+5 VdcC8I/OMD7
A9IMA6B9NAGroundC9I/OMD8
A10IMA7B10NA+5 VdcC10I/OMD9
A11IMA8B11NAGroundC11I/OMD10
A12I-RAS0B12NA+5 VdcC12I/OMD11
A13I-RAS1B13NAGroundC13I/OMD12
A14I-RAS2B14NA+5 VdcC14I/OMD13
A15I-RAS3B15NAGroundC15I/OMD14
A16O-RAMHS *B16NA+5 VdcC16I/OMD15
A17ORB17NAGroundC17I/OMD16
A18OT2 * B18NA+5 VdcC18I/OMD17
A19I-CAS0B19NAGroundC19I/OMD18
A20I-CAS1B20NA+5 VdcC20I/OMD19
A21I-CAS2B21NAGroundC21I/OMD20
A22I-CAS3B22NA+5 VdcC22I/OMD21
A23I/OMDP0B23NAGroundC23I/OMD22
A24I/OMDP1B24NA+5 VdcC24I/OMD23
A25I/OMDP2B25NAGroundC25I/OMD24
A26I/OMDP3B26NA+5 VdcC26I/OMD25
A27I-BE0B27NAGroundC27I/OMD26
A28I-BE1B28NA+5 VdcC28I/OMD27
A29I-BE2B29NAGroundC29I/OMD28
A30I-BE3B30NA+5 VdcC30I/OMD29
A31I-CASPB31NAGroundC31I/OMD30
A32OT1B32NA+5 VdcC32I/OMD31

Note:
   * Type 3 only

-MW: -Memory Write

-MA(0 - 8): -Memory Address (0 through 8)

-RAS(0 - 3): -Row Address Strobe (0 through 3)

-CAS(0 - 3): -Column Address Strobe (0 through 3)

-CASP: -Column Address Strobe Parity

MDP(0 - 3): Memory Data Parity (0 through 3)

MD(0 - 31): Memory Data (0 through 31)

-BE(0 - 3): -Byte Enable (0 through 3)

R: This signal is used with the 'T' signal (pin A32) by the Memory Card Definition register (POS Register 3) to indicate the presence of memory in each of the two system board memory connectors. See" Memory Card Definition Register" on page 2-36 for additional information.

Note: Type 2 system board POST routines require a minimum of 1 MB of functional memory installed in connector 1. The Type 1 system board also requires a minimum of 1 MB of functional memory; however, it may be installed in either connector. The Type 3 system board POST routines require 4 MB of functional memory installed in connector 1.

T1, T2: These signals are used with the 'R' signal (pin A17) by the Memory Card Definition register (POS Register 3) to indicate the presence of memory in each of the two system board memory connectors. See Section 2, "Programmable Option Select," for additional information.

-RAMHS: This signal is used by POS Register 4 to detect the memory speed.

David Beem insinuates:

The connector is 3 rows (A, B, & C) by 32 columns. These are marked well, except for the 2Mb board. Put it chip-side down, connector at the bottom. The solder pads for the connector on the circuit board now have pin A1 in the lower lefthand corner, something like this:

             Solder Side

C1 oooooooooooooooooooooooooooooooo C32
B1 oooooooooooooooooooooooooooooooo B32
A1 oooooooooooooooooooooooooooooooo A32
---------------------------------------
              Connector
---------------------------------------

Presence Detection

We are mainly interested in pins A17 & A32, wired on all Model 80 types, & pins A16 & A18, N/Cs on the Type 1 planars, wired for the Type 2 and 3 planars. An 'X' on the chart means the pin is tied to ground.

SizeA16A17A18A32
1 MBXX
2 MBX
4 MBXXX

   This explains why the 4 MB modules are treated as 2 MB in a Type 1 planar. I don't know if any of the presence detects signify memory speed. The chart above shows the newer 2 MB board. Another surprise is the little memory cards that go on the @FAFF.ADF 2 - 6 MB 386 Memory expansion board are the same pinouts. Of course each board is 2 MB & the presence detect is the same as above. I don't believe this board was offered in any other capacity. You can use one of these little cards on the planar, although it has to be in the slot furthest from the power supply due to the keying & right-angle of the connector. At least the chips are conventional & marked as 85 ns.

From Peter:
   How about that comparison chart below ? I once made it to build a "Mod.80-to-72pin" converter - an attempt that failed so far, by various reasons. (Lack of time mostly)

Pinout Comparison with 72-pin SIMMs

       IBM PS/2 Mod 80                    IBM PS/2 Mod. 70 
       Memory Daughter Card               72-pin SIMM 
A01   NA    Reserved 
A02   O     -Memory Write         Write Enable        O   47 
A03   O     -MA 0                 Address 0           O   12 
A04   O     -MA 1                 Address 1           O   13 
A05   O     -MA 2                 Address 2           O   14 
A06   O     -MA 3                 Address 3           O   15 
A07   O     -MA 4                 Address 4           O   16 
A08   O     -MA 5                 Address 5           O   17 
A09   O     -MA 6                 Address 6           O   18 
A10   O     -MA 7                 Address 7           O   28 
A11   O     -MA 8                 Address 8           O   31 
A12   O     -RAS 0                RAS 0               O   44 
A13   O     -RAS 1                RAS 1               O   45 
A14   O     -RAS 2                RAS 2               O   34 
A15   O     -RAS 3                RAS 3               O   33 
A16   O     -RAMHS (Type 3) 1
A17   O     -R (Mod. inst.) 2
A18   O     T2     (Type 3) 3
A19   O     -CAS 0                CAS 0               O   40 
A20   O     -CAS 1                CAS 1               O   43 
A21   O     -CAS 2                CAS 2               O   41 
A22   O     -CAS 3                CAS 3               O   42 
A23   IO    -MPD 0                Parity Data 0       IO  36 
A24   IO    -MPD 1                Parity Data 1       IO  37 
A25   IO    -MPD 2                Parity Data 2       IO  35 
A26   IO    -MPD 3                Parity Data 3       IO  38 
A27   O     -BE 0                 Block Select 0      O   29 
A28   O     -BE 1                 Block Select 1      O   46 
A29   O     -BE 2                 Block Select 2      O   66 
A30   O     -BE 3                 Block Select 3      O   71 
A31   O     -CASP                 -CAS P              O   11 
A32   O     T1 (Mod. Size) 4
B01   NA    Ground                Ground              NA   1 
B02   O     +5VDC                 +5VDC               O   10 
B03   NA    Ground                Ground              NA  39 
B04   O     +5VDC                 +5VDC               O   30 
B05   NA    Ground                Ground              NA  72 
B06   O     +5VDC                 +5VDC               O   59 
B07   NA    Ground 
B08   O     +5VDC 
B09   NA    Ground 
B10   O     +5VDC 
B11   NA    Ground 
B12   O     +5VDC 
B13   NA    Ground 
B14   O     +5VDC 
B15   NA    Ground 
B16   O     +5VDC 
B17   NA    Ground 
B18   O     +5VDC 
B19   NA    Ground 
B20   O     +5VDC 
B21   NA    Ground 
B22   O     +5VDC 
B23   NA    Ground 
B24   O     +5VDC 
B25   NA    Ground 
B26   O     +5VDC 
B27   NA    Ground 
B28   O     +5VDC
B29   NA    Ground
B30   O     +5VDC 
B31   NA    Ground 
B32   O     +5VDC 
C01   IO    Data 00               Data 00             IO   2 
C02   IO    Data 01               Data 01             IO   4 
C03   IO    Data 02               Data 02             IO   6 
C04   IO    Data 03               Data 03             IO   8 
C05   IO    Data 04               Data 04             IO  20 
C06   IO    Data 05               Data 05             IO  22 
C07   IO    Data 06               Data 06             IO  24 
C08   IO    Data 07               Data 07             IO  26 
C09   IO    Data 08               Data 08             IO  49 
C10   IO    Data 09               Data 09             IO  51 
C11   IO    Data 10               Data 10             IO  53 
C12   IO    Data 11               Data 11             IO  55 
C13   IO    Data 12               Data 12             IO  57 
C14   IO    Data 13               Data 13             IO  61 
C15   IO    Data 14               Data 14             IO  63 
C16   IO    Data 15               Data 15             IO  65 
C17   IO    Data 16               Data 16             IO   3 
C18   IO    Data 17               Data 17             IO   5 
C19   IO    Data 18               Data 18             IO   7 
C20   IO    Data 19               Data 19             IO   9 
C21   IO    Data 20               Data 20             IO  21 
C22   IO    Data 21               Data 21             IO  23 
C23   IO    Data 22               Data 22             IO  25 
C24   IO    Data 23               Data 23             IO  27 
C25   IO    Data 24               Data 24             IO  50 
C26   IO    Data 25               Data 25             IO  52 
C27   IO    Data 26               Data 26             IO  54 
C28   IO    Data 27               Data 27             IO  56 
C29   IO    Data 28               Data 28             IO  58 
C30   IO    Data 29               Data 29             IO  60 
C31   IO    Data 30               Data 30             IO  62 
C32   IO    Data 31               Data 31             IO  64 
                                   Reserved           NA  19 
                                   Reserved           NA  32 
                                   Reserved           NA  48 
                                   PD 0               I   67 
                                   PD 1               I   68 
                                   PD 2               I   69 
                                   PD 3               I   70
Notes:
  1. Contact is tied to GND if the module is High Speed (80 ns)
  2. Contact is tied to GND to signal installed module
  3. If T1=NC and T2=GND the module is 4 MB (25 MHz-boards only)
  4. If T1=GND and R=GND the module is 1 MB (16 MHz boards only)
    If T1=NC and R=GND there is a 2 MB module installed (20 MHz only)
    T2 is not present on 16 & 20 MHz platforms and may not be used

PS/2 Model 80 Presence Detection - Possible Combinations

+--+---+---+--------------------------------------------+
 R  T1  T2   Module Presence / Type Pins 
+--+---+---+--------------------------------------------+
 NC  X   X    No module present in 
 G   G   X    1 MB module installed (16 MHz planar) 
 G   NC  X    2 MB module installed (20 MHz planar) 
 G   NC  G    4 MB module installed (25 MHz planar) 
+--+---+---+--------------------------------------------+

PS/2 Model 70 Presence Detection - Possible Combinations

 7 6 6 6 
 0 9 8 7  <---- Module Pins
+-+-+-+-+-------------------------------------------+
 3 2 1 0   Presence Detect Value 
+-+-+-+-+-------------------------------------------+
 - - - -   No module present    (All planars) 
 G G - G   1 MB / 100 ns Parity  (Type 1 planar only) 
 G G G -   2 MB / 100 ns Parity  (Type 1 planar only) 
 G - - G   1 MB /  85 ns Parity  (Type 1 + 2 planar) 
 G - G -   2 MB /  85 ns Parity  (Type 1 + 2 planar) 
 - G G -   2 MB /  80 ns Parity  (Type 3 + 4 planar) 
+---+---+---+---+-----------------------------------+
 R1  R2   <---- Memory coding on original IBM-modules

Type 1 are full length 16 and 20 MHz planars
Type 2 are reduced length 16 and 20 MHz planars
Type 3 is the 25MHz 386 planar
Type 4 is the 25MHz 486 planar

G = GND measured against Pin 72 (module GND)
- = open connection measured against Pin 72


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