FLIP CHIP details
Here are detailed descriptions of FLIP CHIPs:
M167
This is a 8-bit comparator; it compares the value of two 8-bit numbers and provides four outputs which provide the relationships between those two numbers (A=B, A>B, A>=B, and B>=A). An EQUAL IN input, on pin U2, is provided for cascading them.
Inputs (bits numbered in PDP-11 style, with LSB = bit 0):
| Input | Pin | Input | Pin |
|---|---|---|---|
| A7 | F2 | B7 | H2 |
| A6 | H1 | B6 | S1 |
| A5 | E2 | B5 | D2 |
| A4 | F1 | B4 | E1 |
| A3 | C1 | B3 | D1 |
| A2 | J1 | B2 | M1 |
| A1 | K1 | B1 | M2 |
| A0 | B1 | B0 | A1 |
Outputs:
| Pin | Signal |
|---|---|
| P1 | EQUAL OUT (L) |
| R1 | EQUAL OUT (H) |
| V1 | A>B (H) |
| U1 | B>=A (H) |
| L1 | A>=B (H) |
M203
This contains eight R/S flip flops. They are formed from a pair of NAND gates interconnected in the usual fashion; they provide inverted S and R inputs, and normal and inverted outputs.
M225
This is a 16x16-bit scratchpad memory; this card is used in the KA11 processor of the PDP-11/20, and is documented there.
In addition to 16-bit wide input and output, and byte write controls, it also provides an 4 sets of the 4 address inputs, and 4 inputs to select the desired set of address input. (I.e. the address lines are binary encoded, but the address select lines are not.) An internal 4-way mux selects the desired set of address inputs.
Data pins:
| Input | Pin | Output | Pin |
|---|---|---|---|
| I00 | AF2 | O00 | AE1 |
| I01 | AA1 | O01 | AC1 |
| I02 | AK2 | O02 | AL1 |
| I03 | AH1 | O03 | AJ1 |
| I04 | AE2 | O04 | AF1 |
| I05 | AD2 | O05 | AD1 |
| I06 | AJ2 | O06 | AM1 |
| I07 | AH2 | O07 | AK1 |
| I08 | BR2 | O08 | BM2 |
| I09 | BL1 | O09 | BM1 |
| I10 | BV2 | O10 | BU1 |
| I11 | BP1 | O11 | BR1 |
| I12 | BP2 | O12 | BT2 |
| I13 | BN2 | O13 | BN1 |
| I14 | BU2 | O14 | BV1 |
| I15 | BS2 | O15 | BS1 |
There may be a certain amount of variance between which pin is used for which bit; since the card is purely memory, the bits can be re-ordered without harm.
Control pins:
| Address set select | Pin | Address set A | Pin | Address set B | Pin | Address set C | Pin | Address set D | Pin |
|---|---|---|---|---|---|---|---|---|---|
| A0 | BE1 | AA0 | BF2 | AB0 | BH1 | AC0 | BE2 | AD0 | BF1 |
| A1 | BJ1 | AA1 | BD1 | AB1 | BD2 | AC1 | BC1 | AD1 | BA1 |
| A2 | AP2 | AA2 | AV2 | AB2 | AV1 | AC2 | AU1 | AD2 | AU2 |
| A3 | AS1 | AA3 | AT2 | AB3 | AS2 | AC3 | AR2 | AD3 | AR1 |
Pin BK1 is 'WRITE 15/8', and pin AM2 is 'WRITE 7/0'.
In addition, pin AN1 is a control input of some sort, but it is not yet clear what it does. It is possible that it is some sort of 'output enable'.
M240
This contains six R/S flip flops. They are formed from a pair of NAND gates interconnected in the usual fashion; they provide inverted S and R inputs, and normal and inverted outputs. They differ from the standard SR flops (in the M203, above) in that they have two set inputs.
M602
This is a dual pulse amplifier. It produces a negative-going pulse (nominally 50 nsec wide), triggered by an input transitioning from high to low; the input is a triple-input OR with inverting inputs.
