Large blue (A3) folder of drawings. Cover: MCS 920B COMPUTER DIAGRAM Contents list 920B COMPUTER Logic and Circuit Diagrams of MCB's on Machine No. 62 Data Processing Division MCB1 - Central processor D.D.D. No 22 PL 322A8048 Contents List, typed with red ink corrections 3pp single sided Drawings marked * have red ink annotations. All drawings marked in red "Latest MI Incorporated M.I. 2998. 322A7191 Sht 1 920B L.S.A Element. Logic SYmbols & Circuit Diagrams Issue 4 - Index sheet for LSA diagrams showing issue history for each LSA Sht 2 L.S.A. Design Notes Issue 1 Sht 3 L.S.A. Design Notes Issue 1 Sht 4 L.S.A. Design Notes Issue 1 Sht 5 L.S.A. Design Notes Issue 1 Sht 6 L.S.A. Design Notes Issue 3 Sht 7 LSA 01 2-input NAND Gate Issue 1 Sht 8 LSA 02 3-input NAND Gate Issue 1 Sht 9 LSA 03 4-input NAND Gate + 2 Inverters Issue 1 Sht 10 LSA 04 Control matrix Waveform Amplifiers Issue 1 Sht 11 LSA 05 Issue 1 Sht 12 LSA 06 Issue 1 Sht 13 LSA 07, 13, 34 Pulse Generators Issue 2 Sht 14 LSA 08 Voltage Reference Issue 2 Sht 15 LSA 09, 14 Pulse Generator Issue 2 Sht 16 LSA 11 Cable transmitters Issue 1 Sht 17 LSA 12 Cable Receivers Issue 1 Sht 18 LSA 15 2-input NAND Gate + 2 Inverting Drivers Issue 1 Sht 19 LSA 16 F-Minilog Drivers Issue 1 Sht 20 LSA 17 Paper Tape Receiver Issue 2 Sht 21 LSA 18 Single I/P Noise Rejection Inverter Issue 2 Sht 22 LSA 19 Delay Issue 2 Sht 23 LSA 20, 24, 25 Delay Issue 2 Sht 24 LSA 21 Delay Issue 2 Sht 25 LSA 22 Two Input Transmitters Issue 1 Sht 26 LSA 23 Gated Receivers Issue 2 Sht 27 LSA 28 2-Input NAND Gates Issue 1 SHt 28 LSA 43 Voltage Rail Sensing Issue 1 Sht 29 LSA 44 2-Input NAND GAte Issue 1 322C7432 A3 MSC 920B Computer Connector and Unit Layout issue 3 322D8267 A7 920B Register Bits 1-18 Issue 1 322D5228 7 A-FA Board Pos 37 to 45 & 48 to 56 Registers (Bit 1-18) Issue 5, 4 sheets * 322D5225 8 A-FB Board Pos 8, 9, 34 Initial Instructions Waveform Amplifiers Issue 2 322D5195 9 Board A-FC Pos 4 Timing Issue 4 322D7973 A10 920B Multiply/Divide Shift and Overflow Logic Issue 1, 3 sheets 322D5194 10 A-FD Board Pos 3 Program Interrupt Issue 5 322D7880 A11 920B Control Sequence Functions 0-9 Issue 2, 2 sheets 322C5213 11 Board A-FE Pos 22 Test Process Counter Zero Issue 4 322D7881 A12 920B Control Sequence Functions 10-15, Issue 2, 2 sheets 322C5212 12 Board A-FF Pos 21 Control Matrix Address Logic Issue 3 322D7952 A13 920B Input/Output Overall Logic Issue 1, 2 sheets 322C5211 13 Board A-FG Pos 20 Control Matrix Address Drivers ISsue 1 322D7972 A14 920B Computer Store Logic and General Flow Diagram Issue 1, 2 sheets 322D5189 15 Board A-FH Pos 7 Control Matrix Conditionals A, B, C Issue 3 322D8069 A15 920B Computer Manual Controls and Store Heater Logic Issue 1 322D5197 15 A-FI Board Pos 6 Control/Function Drive; Matrix Cond D, E Issue 3 322D7907 A16 920B Computer Matrix Address Function Decode and Conditionals Issue 1 * 322C5238 16 Board A-FJ Pos 47 Waveform Drivers 1 Issue 2 322D7948 A17 920B Computer Initial Instructions Issue 1 * 322D5237 17 Board A-FK Pos 46 Waveform Drivers 2 Issue 5 322D8070 A18 920B Computer Control and Interrupt Overall Logic Issue 1, 2 sheets 322D5193 18 Board A-FL Pos 2 Manual Control Logic Issue 3 322D7959 A19 920B Computer Register Module and Control Waveforms Issue 1, 2 sheets 322D5248 19 A-FM Board Pos 57 Store Control & Overflow Logic Issue 5 322D5222 20 A-FN Board Pos 31 & 32 Cable Transmitter 1 Issue 1 322C5219 21 Board A-FO Cable Receivers 1 Issue 2 322D4941 A22 920B Computer Control Unit Circuit Diagram Issue 7 322D5214 22 A-FP Board Pos 23, 24 & 25 Process Counter Issue 1 322D4197 A23 920B Store Control Chain (A-EB3 Unit) Issue 3 322D5221 23 Board A-FQ Pos 30 Input-Output Control Issue 4 * 322C4195 A24 920B Computer A-EA3 Unit Issue 3 322D5196 24 A-FR Board Pos 5 Timing Waveform Drivers Issue 4 322C5220 25 A-FS Board Pos 29 Cable Receivers 2 Issue 1 322D7936 A26 Y Selection System for 920B Stores Issue 1 322C5192 26 A-FT Board Pos 1 Control Logic Key Input Issue 4 322D7934 A27 X1-64 Selection System for 920B Stores Issue 1 322C5210 27 Board A-GA Pos 19 Control matrix (Control Chain) Issue 3 322D7930 A28 X65-128 Selection System for 920B Stores Issue 1 * 322C5209 28 Board A-GB Pos 18 Control Matrix Functions 0,1, 2, 3 & 4 Issue 2 322C4201 A29 920B Store Circuit Diagram A-ED3 Issue 4 322C5208 29 Board A-GC Pos 17 Control Matrix Functions 2, 10, 11 Issue 2 322C5207 30 Board A-GD Pos 16 Control Matrix Functions 5, 6 & 9 Issue 1 322D7931 A31 920B Process Counter Issue 1 322C5206 31 Board A-GE Pos 15 Control Matrix Functions 7, 8 Issue 2 322C2781 A32 Circuit Diagram for Selection Diodes 920 A-AE Unit Issue 3 322C5205 32 Board A-GF Pos 14 Control Matrix Funtion (sic) 12 Issue 1 322D4199 A33 Circuit Diagram A-EC3 Unit (920B Master Drivers) issue 4 322C5024 33 Board A-GG Pos 13 Control Matrix Function 13 Issue 1 322C5203 34 Board A-GH Pos 12 Control matrix Function 14 Issue 1 322C4885 A35 Circuit Diagram A-GZ Unit Temp Sensing & Control) Issue 6 322C5202 35 Board A-GI Pos 11 Control Matrix Function 14A Issue 3 322C5201 36 Board A-GJ Pos 10 Control Matrix Function 15 Issue 2 322C5227 37 Board A-GK Pos 36 Initial Instructions 1 Issue 3 322C5226 38 Board A-GL Pos 35 Initial Instructions 2 Issue 1 322D7819 39 920B Computer Power Supply Mains Input MCB24 Issue 1