IBM 1620 1 Manual Download

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Summary of Contents for 1620 1

Page 1: ...and 1627 Plotter In structions peculiar to the 1710 System are explained in the 1710 manual referred to below 1620 Operator s Console Modell including the console input output typewriter 1620 8 track...

Page 2: ...130 Pages 24 26 46 80 Dated 4 1 65 7 19 65 Copies of this and other IBM publications can be obtained through IBM Branch Offices Comments concerning the contents of this publication may be addressed to...

Page 3: ...e Typewriter 1620 Console Control Switches Keys and Signal Lights Program Switches and Indicators 1620 Console Operating Procedure Page 1 3 3 4 6 7 7 7 9 12 12 17 23 29 30 34 36 39 43 51 52 55 55 57 6...

Page 4: ......

Page 5: ...is one millionth of a second IBM 1620 Data Processing System The 1311 Disk Storage Drive provides unlimited random access storage for the cpu Information stored on removable disk packs is available wi...

Page 6: ...Console typewriter operator s speed The system provides output information via the 1622 the tape punch in the 1621 the console type writer the 1443 Printer and the 1627 Plotter The 1621 and 1627 unit...

Page 7: ...or correct parity To create this odd bit number a C bit is automatically added when required to each digit position as data enters core storage Thereafter during processing a digit position with an ev...

Page 8: ...ft to right into successively higher numbered core storage positions 4 Output and internal record transmission are termi nated when a record mark is sensed except for card output which is terminated o...

Page 9: ...git Memory Buffer Register MBR as bUs The function of the MBR is to receive digits entering or leaving core storage Digits leaving storage are 4 regenerated through the MBR In effect the MBR is subdiv...

Page 10: ...tation The 1620 can be programmed to read and write numeric and alphameric data The input output in struction numeric or alphameric determines wheth er data is read and or written numerically or alpha...

Page 11: ...r and is analyzed to 1620 Instructions determine the operation to be performed The address of an instruction must always be even i e the 0 0 digit of an operation code must be stored in an even number...

Page 12: ...mediate instructions use the digits in the Q7 Qs Q9 QlO and Ql1 positions of the instruc tiOn as data instead of as a core storage address Thus the Q data is located immediately within the instruction...

Page 13: ...ist within the field The P or Q address of an instruction is indirect when a flag bit is over the units position Figure 7 shows that 1 the instruction 21 00500 00650 has an indirect P address of 00500...

Page 14: ...data flow diagram for an Add Immediate in struction 11 00500 00650 is shown in Figure 9 The Q data 000650 is added to the data at the address specified by the indirect P address The result 1155078 re...

Page 15: ...49100500100000 I v J The OP code for the new instruction is contained in core storage locations 16000 and 16001 Figure 10 Indirect Addressing Branch Instruction CORE STORAGE To Instruction Registers 1...

Page 16: ...ode P Q P 21 X 11 X 22 X 12 X 23 X 13 X 28 X 18 X 29 X 19 X 01 X 02 X 03 X 09 X 24 X 14 X 49 X 44 X 45 X 55 X 43 X 46 X 47 X 27 X 17 X 42 07 X All 1620 instructions with their associated Op codes mnem...

Page 17: ...ue method of doing arithmetic calculations is used in the 1620 Two tables Multiply and Add stored in the table area of core storage are auto matically referred to by the computer during arith metic op...

Page 18: ...Value at 09400 02 P Value at 00500 12 Sum at P 14 replaces original value Figure 12 Add Instructions Data Flow 14 l I I l SUBTRACT True Comp True True Comp I I I tained For sums other than zero the s...

Page 19: ...gits in the initial field at the P address I Address of I Address of I Op Code r Multiplicand Multiplier 1 Multiplicand Value 12 Multiplier Value 02 Product Value 0024 Figure 13 Multiply Instruction D...

Page 20: ...product area may be formed but positions in excess of 20 digits must be cleared to zeros by pro gram instructions preceding the Multiply instruction It is possible to develop a product so large that i...

Page 21: ...00096 00650 21365 Load Dividend 2 28 00099 00650 01234 Load Dividend 3 18 00098 00650 56789 Load Dividend Immediate Figure 14 Load Dividend Instructions Automatic Division Load Dividend LD 281 Descri...

Page 22: ...ractions with the units position of the divisor at 00099 The quotient and remainder replace the dividend in the product area The address of the quotient is 00099 minus the length of the divisor The al...

Page 23: ...ght No overdraw Subtract divisor Overdraw Add back divisor to correct overdraw Store third digit of quotient 1 Subtract divisor one place to the right No overdraw Subt ract divisor No overdraw Subtrac...

Page 24: ...ctions 7 x 24 168 Overdraw Correction Store quotient digit 8 8 successful subtractions 8 x 24 192 Overdraw and correction not shown Store quotient digit 8 3 successful subtractions 3 x 24 72 Overdraw...

Page 25: ...btraction No 1 No 2 No 3 No 4 No 5 No 6 No 7 No 8 No 9 11 No 10 Figure 17 Divide Overflow the program must provide for a flag to be set in the desired position Loss of One or More High Order Digits of...

Page 26: ...determined by the number of quotient digits desired An anaylsis of the problem and its relationship to these rules is necessary 3 First subtraction P address of divide instruc 2 2 1 0 4 0 II 1 9 0 2...

Page 27: ...Floating Point Operations range of intermediate and final results This anaylsis and subsequent number scaling frequently takes longer than does the actual calculation Furthermore number scaling requi...

Page 28: ...c is described with each in struction These operations are automatic and need not be programmed Of particular note is Floating Divide which requires only one instruction the divi dend is positioned di...

Page 29: ...order position of the mantissa and a one is added to Ep Figure 24 When an overflow does Core Storage Locations Core Storage Locations 01590 01S99 Instruction 01590___01599 Before After IEpl1 v q IEq O...

Page 30: ...Core Storage Locations Core Storage Locations 01590 01599 Instruction 01590 01599 Before After Iv p I Ep I Mq I Eq OP I P I Q Iv p I Ep I Mq I Eq i 2 3rO 117 8 910 4 o 910 1 5 9 410 1 5 9 9 i 5 510 3...

Page 31: ...operation the core storage locations appear as follows not that the flag bit in 01598 has been cleared MMMMXXXXMMMMEE Upon completion of the operation the mantissa is incorrect as follows MMMMOOXXMMM...

Page 32: ...ches section Figure 34 High Positive 11 The H P indicator and light are turned on when the mantissa resulting from a floating point computation is greater than zero Equal Zero 12 The E Z indicator and...

Page 33: ...order until terminated by the flag bit marking the high order position of the field at the P address High order zeros are supplied when the size of the Q field is less than that of the P field The Hi...

Page 34: ...e unconditional or con ditional Unconditional branches are executed as the Op code directs Conditional branch instructions are performed or not performed depending on the condi tion tested Branch B 49...

Page 35: ...Branch and Transmit Immediate BTM 17 Description Same as Branch and Transmit BT 27 except that the digits in the Q part of the instruction are used as Q data Execution Time T 200 40D Il sec Branch Ba...

Page 36: ...e after reading the last data record terminated 32 by the first of the two successive EL punches the next read instruction causes the second EL punch to read in A Branch No Record Mark instruction whi...

Page 37: ...et key only 33 Channel 9 No Punched hole in Channel 9 of carriage BI BNI 1620 Reset key or a punched hole in control tape Channell of carriage control tape 34 Channel 12 No Punched hole in Channel 12...

Page 38: ...it 0 at 09211 is transmitted to the core storage location Core Storage specified by the P address 09400 The 3 at 09400 is replaced by the 0 which also remains in 09211 If a flag bit is located at Ql1...

Page 39: ...transfer Transmission proceeds serially from left to right until terminated by a record mark The transmitted record including flag bits and the record mark replaces all data in the record at the P ad...

Page 40: ...negative OPERATION P MNEM NUM Instruction _ _ _ 0 1 2 3 4 5 6 MF 17 I 13259 P Field e before I 2 3 4 Core Storage Addresses Storage after Wove Flag over the 3 is cleared because there is no flag over...

Page 41: ...umeric field is specified by the Q address Transmission of the numeric field is specified by the Q address Transmission of the numeric digits from the odd numbered positions proceeds from the posi tio...

Page 42: ...storage lacations and the fact that the Read Alphamerically instruction ignores the Hag bits in the read in field If Hags are developed in the alpha meric field during th6 program care should be take...

Page 43: ...Power on switch on correct placement of disk pack etc and the CPU restarted The master 1311 s Meter switch must be on to operate any slave 1311 Read Numerically RN 36 Description Numeric information...

Page 44: ...ed of the input unit selected and the number of characters read Execution time is 3 4 ms for transferring 80 columns of data from the 1622 input buffer storage to core storage Read Alphamerically RA 3...

Page 45: ...nit Transmission continues until terminated by one of the follOWing conditions 1 Sensing of a record mark character in core storage The record mark character is not written on the typewriter but cause...

Page 46: ...on is transmitted serially to an output unit beginning with the P ad dress and continuing through successively higher numbered addresses Transmission tenninates after the character has been written fr...

Page 47: ...tain a modifier digit to define a particular function within the regular Read Numerically or Write Numerically operation The general areas of function definition are as follows 1 Read or write a speci...

Page 48: ...itten At the beginning of the operation the sector count is transferred to a 1620 register PR 3 which is decremented by one before each sector is processed The operation is terminated when the sector...

Page 49: ...tinue and overlap the seek operation When the 1311 is attached to the 1710 Control Sys tem a Seek Complete interrupt is available as part of the Input Output Interrupts special feature The Seek Comple...

Page 50: ...he Write Address key must be off Compare data in specified number of disk secton with data in core storage Check length of record Transfer addresses and data from the 20 sectors of one track to core s...

Page 51: ...are replaced by data from core storage Execution Time Average T 22 25 ms Check Disk WLRC CDGN or 36 Q 11 of 1 This instruction provides the means for checking data written in disk storage against the...

Page 52: ...laced in the location 48 following the 2100th character position to allow suffi cient core storage positions for the five address posi tions followed by the 100 data positions for each of the 20 secto...

Page 53: ...ks in the record in disk storage are transmitted as data group marks in the record in core storage are replaced by data Execution Time Average T 22 25 ms Write Disk WDN or 38 Qll of 2 Data is transfer...

Page 54: ...heck indicator turns on When the same record is read back into core storage the group mark in disk storage stops the opera tion and turns on the Wrong Length Record Check indicator 2 If 300 position r...

Page 55: ...to maintain correct parity The original digit at the P address remains unchanged The Q part of the instruction is not used Execution Time T 200 JLsec Clear Flag CF 33 Description If a flag bit is pre...

Page 56: ...ons until the Release key is pressed It should be noted that the decimal point or period character in either upper shift or lower shift may be entered only with a Read Alphamerically instruc tion If e...

Page 57: ...e to the point to be cleared and press the Tab Clear lever To clear all stops at once position 1 5 1 7 Carriage Return Guard the carriage at the right margin hold down the Tab Clear lever and return t...

Page 58: ...stop is set as follows a Return the carriage to the present left margin stop b Press and hold down the Nlargin Set key c Move the carriage manually as near as pos sible to the position desired With t...

Page 59: ...f position Set to the Figure 52 1620 Control Keys and Signal Lights 1620 Console o position it applies electrical power to the com puter and turns on the Power On Light Power Ready Light The Power Rea...

Page 60: ...the key is pressed The Stop SIE key also serves as a single instruction key Successive depressions of the key cause one in struction to be executed for each depression The Manual light remains on 56...

Page 61: ...Program and four Ma lM1t CHIC PO SWITCHES eH MU CI tlOCHI p cwa OH 0 ee 1to __ 0 OUt wa CHk AltIT CHW 9 eM I STOP SlO STOf OM OGRAIo4 Figure 53 Indicator Lights and Switches chine Check are provided...

Page 62: ...k Light This light and indicator are turned on when the digit in the odd address portion of the MBR has a parity 58 error An error halts the machine immediately if the Parity Check switch is set to ST...

Page 63: ...The two stored digits affected by a core storage address are displayed in the MBR When the core storage location addressed for display is an even numbered adress the digit at this location is placed...

Page 64: ...tary switch should not be turned how ever while the Display MAR key is depressed The MARS registers provide a visual indication of internal data flow for the console operator Further information on th...

Page 65: ...position of the indirect ad dress Field Mk 1 Field Mark 1 The Field Mark 1 light comes on when the flag bit in the high order position of the Qfield is detected in the MDR Field Mk 2 Field Mark 2 The...

Page 66: ...Figure 55 Control Cates Lights 62...

Page 67: ...Figure 56 Instruction and Execution Cycle Lights 63...

Page 68: ...m storage xxxxx and branch to first program instruction Releases typewriter The Read Numerically instruction entered in step 2 is executed As each character is typed it is stored at location xxxxx and...

Page 69: ...ucceedingly higher numbered core storage positions Terminates Read instruction The next sequential instruction which is Branch Back step 4 to the address saved in PR 1 step 2 is executed and processin...

Page 70: ...struction that contains the desired address is next Press the SeE key eight times Press Reset key Turn MARS switch to OR 1 Operand Address Register 1 and depress the Display MAR key Turn MARS switch t...

Page 71: ...AR OR l OR 2 Incr Decr Switch MBR 0 E r f Figure 57 Diagram of I Cycle Program Testing Operand Address Register 1 OR I Q address of the instruction in the Op register Operand Address Register 2 OR 2 P...

Page 72: ...ition the MARS Display switch to select the desired register 3 Press the Display MAR key During machine operation MAR is addressed by the 12 MARS registers The MARS register that addresses MAR varies...

Page 73: ...providing locations of data in core storage They are decremented since this is a digit by digit opera tion OR 3 retains the P address for sum recomple ment if necessary 2 5 Add Table New P Data I 0 1...

Page 74: ...omplemented Multiplication Multiplication is accomplished in the 1620 by combin ing the digits to be multiplied into a Multiply table address The answer is then looked up in the Multi ply table Refere...

Page 75: ...developed product is 024 10 The P units digit 2 goes into the tens posi tion of MAR 11 The Q tens digit I is doubled etc as de scribed in Step 3 Add Table New P Data 1 1 8 3 Add Table 1 m 1 3 3 Add T...

Page 76: ......

Page 77: ...e again The MARS registers are used during multiply opera tions as follows l PR 1 is set to 00099 units position of product area 2 OR 3 is set to OR 2 units position of multi plicand OR 3 retains that...

Page 78: ...is transferred to MDR for processing Both digits read back into core storage MAR receives core storage addresses from the twelve MARS registers The function of each MARS register is given in Appendix...

Page 79: ...ard i Translation _____________ J Paper Tape 14 Parity L iR e sag de r 1 j r Check Figure 67 1620 CPU Data Flow Card t Reader I C F CI Incr IIncr I 1 2 I I Bit Drivers it J Jt 1 1 Digit Brancll Reg st...

Page 80: ...Clear Flag 33 CF 200 Compare 24 C 200 80 DZ unlike signs DZ Number of positions compared 160 80 Dp like signs until a digit other than zero is detected in either field Compare I 14 CM Same as above C...

Page 81: ...sic Time If signs initially alike and numerical 80 Dp Recomp Time value of Q data greater than P data Subtract I 12 SM Same as above Same as above Transfer Numerical Fill 73 TNF 160 40 Dp Transfer Num...

Page 82: ...0 0 0 0021 5 0 6 0 7 0 8 0 9 0 0022 0 1 2 1 4 1 6 1 8 1 0023 5 1 8 1 1 2 4 2 7 2 0024 0 2 4 2 8 2 2 3 6 3 0025 5 2 0 3 5 3 0 4 5 4 0026 0 3 6 3 2 4 8 4 4 5 0027 5 3 2 4 9 4 6 5 3 6 0028 0 4 8 4 6 5 4...

Page 83: ...of an instruction In disk storage operations contains core storage address where data from disk storage is written to or read from Retains address of low order multiplier digit during multiplication...

Page 84: ...erations can be in numeric mode only Two digit character representations is shown for convience Dump Numerically instruction only For Write Alphamerically and Write Numerically instructions an EOl cha...

Page 85: ...1 3 X21 X21 11 3 L 4 4 CX4 CX4 11 4 4 CX4 CX4 11 4 M 5 5 X41 X41 11 5 5 X41 X41 11 5 N 6 X42 X42 11 6 6 X42 X42 11 6 0 7 7 CX421 CX421 11 7 7 CX421 CX421 11 7 P 8 8 CX8 CX8 11 8 8 CX8 CX8 11 8 Q 9 1 X...

Page 86: ...its position of field compared with Q field Same as Code 14 Location to which digit is transmitted Same as Code 15 Location to which units position of field is transmitted Sames as Code 16 Same as Cod...

Page 87: ...de 43 46 Branch On Indicator Same as Code 43 47 Branch No Indicator Same as Code 43 48 Halt Not used 49 Branch Location of next instruction executed 55 Branch No Group Mark Not used 71 Move Flag Locat...

Page 88: ...punch and a digit punch is used The various combinations of punches which represent the alphabet are based upon a logical struc ture or code The first nine letters of the alphabet A to I are coded by...

Page 89: ...99999999999199999999 I 2 3 456 1 8 910 I Il14151611181S 101122 2324 25262129293031323J 34353631383940414243 444546414849505152535455 165158 59606162636 61 61 68 691011111314151611791980 Column Numbers...

Page 90: ...s Association specifications RS 227 The specifications for dimensions of punched tape can be determined after conditioning the tape to the following requirements for 24 hours 75 F 3 50 50 RH 2 Tape Sp...

Page 91: ...ends overlapped by at least one tape column and held together with an adhesive With some splicing equipment the pieces are weld ed together through a process of heat pressure and a liquid bonding agen...

Page 92: ...oximately one per minute With other butt joint splicing equipment the paper is bonded to the overlay material by an adhesive on the overlay material Alignment accuracy of the tapes depends upon the sk...

Page 93: ...2 36 00031 00300 NoOp Read paper tape into 00031 00024 25 00071 ddddd Transfer digit from location ddddd to 00071 Appendix G Program Load Routines 00036 36 aaaaa 00300 Read paper tape into aaaaa 00048...

Page 94: ...o 00079 by the Load key Note that each of the last four instructions contains an indirect address referring to a field in the input area Refer to the PROGRAM CARD FORMAT for an explanation of each in...

Page 95: ...followed by blanks Blank Cards 5 and 6 show a method of loading a record mark between instructions If a record mark is to be loaded to location 00811 the record mark in column 31 of card 5 must be om...

Page 96: ...Branch Instructions 30 Exponent Underflow 29 Branch Light 61 Branch No Flag instruction 32 Branch No Group Mark instruction 33 Branch No Indicator instruction 33 Branch No Record Mark instruction 32 B...

Page 97: ...endix B 78 Read Disk Track WLRC instruction 48 Read Numerically Instruction 39 Reader No Feed Light 1620 Console 56 Read Only Flag 44 RECOMP light Recomplement 61 Record 4 Record Marks 4 Release key 5...

Page 98: ...isk Storage Drive 1 2 Write Check Light 1620 Console 58 1311 Instructions 43 Write Disk instruction 49 1443 Printer 1 2 Write Disk WLRC instruction 47 1620 CPU Model 1 3 Write Disk Track instruction 4...

Page 99: ...International Business Machines Corporation Data Processing Division 112 East Post Road White Plains N Y 10601 USA Only IBM World Trade Corporation 821 United Nations Plaza New York New York 10017 Int...

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