Manual / Guide · 1971
Hewlett-Packard's January 1971 service manual for the 9100A and 9100B: pseudo-hardware problems, performance assurance, troubleshooting (verify the problem, check the CRT, troubleshooting tree), assembly locations, the standard and optional supply and deflection-amplifier schematics, waveforms, replaceable parts and backdating. 110-page black-and-white scan.
HEWLETT M2 PACKARD Service Manual H/P Part No. 09100~- 90034 HEWLETT-PACKARD CALCULATOR Models:9100A 9100B SERIALS PREFIXED 945-03675 — 9100A 938-02251 ~ 9100B Page 73, Manual Backdating Changes adapts this manual to all prior serial prefixes. Copyright Hewlett-Packard Company, 1971 P.O. Box 301, Loveland, Colorado, 30537 U.S.A. 09100-90034 Microfiche No. 09100-90036 Printed JAN 1971 TABLE OF CONTENTS ¥ me SECTIONS g INTRODUCTION ....... cece cece ccc cere eee rete cence eeeees 1 PSEUDO-HARDWARE PROBLEMS ........... 20... cceeccceeccces 2 9100 A/B Improper Magnetic Card Entry ........... 0.2 cee cee eeee eee 2 Program Steps In Memory Changed to Y>() or ACC +........... 2 RO Incorrect Polar Conversion ............ 0. cece cee cece eer cces 7 pS Pressing Two Keys Simultaneously ........... 0. ccc ee eee ccc eee 7 i Ambiguous Equality 2.0... 0... 0. cece ce cect en eet cece recs 8 + Incorrect Int X Key Operation ........... ccc cece cece eee e cece 8 : Display Changes If An “IF” Key Js Pressed ..... bbe eee eee enone 8 9100A } Incorrect Program Step Loaded Into Memory From Magnetic Card ........0 0.2 cece ec eee ee tee eens 9 Keyboard Digit Entry Becomes A Part of the Number in the X Register ........... 0. cc cece ee ec eee e eee nee 10 Program Execution Starts When STEP PRGM Is Pressed ......... 10 Turning Calculator On Lights Error Lamp ..............0--0-005 11 9100B Unusual Z Register Display ..........--.. 0.0 eee eee ee eee 12 Unexpected Results Obtained From Operations Following “IF” Instructions ......... 2. e ec cece cee cece ec eeee ‘ e Unexpected Results Obtained From A GO TO () () cS IMstructiOn 2.0... ccc ce cee eee ee eee eee eer tees 13 es Keystrokes Do Not Appear In X.. 0... .... cc cee ee ee cee ees 14 is Subroutine Called From Keyboard Will Not Return oe Control to Main Program ........ 0. cece eee eee ee eee e eens 14 a Pressing STEP PRGM Causes Multiple Key Execution ........... 14 g PERFORMANCE ASSURANCE ................-..0 2c cere eee eeee 15 TROUBLESHOOTING Step 1 Verify the Problem ..............-..20. Lecce eee ee eee 25 Step 2 Check the CRT ....... cee cece eee eee eee cette 25 Step 3 Troubleshooting Tree ........ 00. ce eee eee eee etree eee 26 The Intermittent Calculator... 1... .. cee ce te ccc eect eens 26 Field Repairable Assemblies ............. 00-2 ee eee eee rece eees 27 Modified Calculators ... 2... 0. ccc cc cee ee ee ee eee eee eee eens 27 a Interchangeable Assemblies ............ 00 cece cece eevee cccccs 27 A20 Power Supply Replacement ............- 0c eee ee ee ee ee eens 28 REPLACEABLE PARTS ...... 1... cee cece ee eee ee teen neers 7 3 ie ii fH BACKDATING .... 1... cece ee cece ce ee ce ee terete ee eeee 73 hi TABLE OF CONTENTS APPENDIX A 9100A Diagnostic Program APPENDIX B 9100B Diagnostic Program APPENDIX C Code List of Manufacturers APPENDIX D Sales and Service Offices 1. Assembly Mounting Screws ......... 00. c ce eee eee terete neee 16 1. The 9100A’s 19 Accessible Registers.............. 00 ese eee eens 3 2. Display of Register X, Y or Z 2... ec ce te et eee eee nee 4 3. A Program Recorded On A Magnetic Card ..............0-c eee eee 9 4. Location of Assembly Mounting Screws ..............00 eee eens 15 5. Keyboard Bezel Mounting Screws .........--.. 2c eee ec ee veces 16 6. A5 and A40 Assembly Mounting Screws .............. 00 ee ee eeee 17 7. Assemblies of the 9100A/B ... 2.0... 2c eee eee ee ee eee eens 18 8. Service Chain Installation... 2.0... 0.00... eee ee eee eee ee eee 19 9. The A20A2 Assembly ......... cc cece we eee cree eee eens 20 . A Properly Adjusted CRT Display .............. 2. ec eect eee 21 11. Original Bottom Case Configuration ............. 0... ee eee eee 29 12. First Configuration for Bottom Case With 115/230V Power Outlet... 30 13. Second Configuration for Bottom Case With 115/230V Power Outlet . 30 14. Third Configuration for Bottom Case With 115/230V Power Outlet .. 30 15. Checking the Bottom Assembly .......-......-02e eee ee eens 31/32 16. Troubleshooting Tree... 12. ccc ec ee ee tet e eens 33 17. Standard Vertical Deflection Amplifier Waveforms ................ 34 18. Standard Vertical Deflection Amplifier Schematic ................ 35 19. Standard Horizontal Deflection Amplifier Waveforms .............. 36 20. Standard Horizontal Deflection Amplifier Schematic ........... 37/38 21. Composite Standard Horizontal and Vertical Deflection Waveforms .. 39 22. —3500 Voit Power Supply Oscillator .......... 0... ccc eee eee 40 23. Standard —15V and —3500V Power Supply Schematic ......... 41/42 24. Optional (Current) Vertical Deflection Amplifier .............. 43/44 25. Optional (Current) Horizontal Deflection Amplifier Schematic ... 45/46 26. —3500V and Optional (Voltage and Current) —15V Power Supply Schematic ................. 0c cee cece 47/48 27. Optional (Voltage) Vertical Deflection Amplifier Schematic ..... 49/50 28. Optional (Voltage) Horizontal Deflection Amplifier Schematic ... 51/52 29. 9100A/B Common Parts .......... 0. cece cee eee ee eee eee eeeee 59 30. Unique 9100A and 9100B Parts ........ 2... ccc ccc eee eee eee 60 TABLES ILLUSTRATIONS ol ©) INTRODUCTION This manual contains the field service information required to maintain the Hewlett-Packard Models 9100A and 9100B Calculators. The similarity of the instruments and their service concept allows this information to be included in one manual. In this manual, the terms “9100A/B” and “’calculator’’ will refer (unless otherwise noted) to either the 9100A or 91008 Calculator. The 9100A/B Calculator is maintained with a service kit. The service kit (available in several versions; see REPLACEABLE PARTS) provides the Field Service Engineer with the tools and parts necessary for maintaining the calculator in a field situation. The 9100A/B is repaired by exchanging good assemblies from the kit for defective assemblies in the calculator. When the calculator is restored to use, - any defective assembly is returned to the nearest Hewlett-Packard Sales and Service Office for exchange. Four assemblies are repaired in the field to component level; they are the horizontal and vertical deflection assemblies (A15 and A16, respectively) and the power supply assemblies (A20 and A21). SERVICE CONCEPT PSEUDO-HARDWARE PROBLEMS INTRODUCTION Several operating characteristics of the 9100A/B Calculator could be inter- preted as instrument malfunctions; therefore, the Field Service Engineer should ensure that an instrument malfunction exists prior to troubleshooting a calculator. This section will cover the most common pseudo-hardware of the A/B, A and B, respectively. 3100A/B IMPROPER “= | the calculator’s memory is unchanged except for core memory location 0-0 MAGNETIC ‘; (or the starting address), which is changed to 77g, check to be sure the CARD ENTRY “customer is not putting the magnetic card in backwards, that is, the printed side of the card toward the display bezel rather than toward the keyboard. If the card is put in the cardreader backward and the ENTER key is pressed, the read heads of the cardreader will have no data input; therefore, the program .. counter of the calculator will not be advanced. When the card is ejected from ‘js the cardreader, the read heads pick up the electrical noise of the card-eject #: switch and load an octal code 77 into the memory location 0-0 (or the *.. starting address). The same symptom will be observed if an unrecorded or <" accidentally erased magnetic card is used. PROGRAM STEPS if, after one pass through a program, a register (or registers) previously IN MEMORY containing program steps now contains Y~() or ACC + instructions (octal CHANGED TO codes 40 and 60 respectively), check to be sure that the program has not Y>() OR ACC+ loaded data in registers that previously contained program steps. The explanation of why octal code 40 and 60 are predominate in this situation begins with the core memory and ends with the display. Throughout the following discussion the 9100A will be used as an illustration, but the material applies equally to the 9100B (unless otherwise stated}. The core memory of the calculator (See Figure 1) contains 19 accessible registers (0-9, a-f, X, Y, Z). (The 9100B also has an additional negative page (—) containing registers {(-)0-9, (—)a-f.) The registers contain 14 characters, each character contains 6 bits (F20-F25). PSEUDO-HARDWARE PROBLEMS 9100A/B ae o 1 2 3 4 Se 7 8 9 9b og alge a ; ee 2c 2 pence : Ae 5 Vy ga 6 sce 4 PROGRAM a. SA w |] 047A STORAGE ge - 8 @ j| REGISTERS apa oh Aad ‘ “| A c2 c Leet A a. e ge . }aeer SEEKL 4 apa y OISPLay Zpn ‘ REGISTERS LT ~ 2 AC WIT AAA Ak A 3 Figure 1. The 9100A’s 19 Accessible Registers Each character location will contain either an instruction or a digit. First, let’s cover the situation of a character holding an instruction. The six bits are assigned the following octal weight: BIT F20 F21 F22. F23. F24 = F25 OCTAL WEIGHT 1 2 4 10 20 40 A maximum of octal code 77 can be stored in a character, giving each character location the capability of storing any calculator instruction {see calculator pull-out card). The following chart contains examples of a character storing different calculator instructions. PROGRAM STEPS IN MEMORY CHANGED TO Y>() OR ACC+ (Continued) PSEUDO-HARDWARE PROBLEMS 4 §100A/B F20 F21 F22 F23 F24 F25 BITS OCTAL WEIGHT KEYS : ee TOTAL OCTAL WEIGHT ACC + 0 0 0 0 J J 60 STOP 1 0 0 ) 0 1 41 vx 0 1 1 1 1 1 76 PAUSE | 1 1 1 1 0 1 67 NOTE The octal code 77 is not required for a keyboard instruction, but is used as an internal calculator instruction (In 10). (In the 9100B octal code 77 is the SUB RETURN instruction.} When a character contains a digit rather than an instruction, only bits F20, F21, F22 and F23 are required to define that digit. Bits F24 and F25 contain the sign and blanking information. If bit F24 is a one, the digit is negative. If bit F25 is a one, the digit is blanked. F20 | F213 | F22 | F23 | F24 | F25 BITS BLANKED |+ 1 2 4 10 20 40 DIGIT [22 1 1 0 0 0 1 ) 21 NO - 3 1 1 0 0 0 0 3 NO + 5 1 0 1 0 1 0 25 NO - 7 1 1 1 0 0 0 7 NO + 9 1 0 0 1 1 0 31 NO - The CRT display is stored in the X, Y, and Z registers. The display of one of these registers in floating point is shown in Figure 2. It consists of ten digits (Dg ---- Og), two exponent digits (E, and Eo) and two guard digits (Gy and Gg), which are always blanked. The two guard digits perform the function of rounding. Dg Dg D7 Dg Bh Dg D3 Do D; Do {Gy Go) E; Eg | TT most least blanked exponent significant significant guard digit digit Figure 2. Display of Register X, Y or Z PSEUDO-HARDWARE PROBLEMS S9100A/B If the CRT display in Figure 2 were being held in any register, it would be = * held in the following manner: oo Register XQ 2X1 &K2 X3 X4 MS XG X?F? XB X9 Xa Xb Xe Xd Display Dp 0, Og 03 Dg Dg Dg Dz Dg Dg Eg £y Go Gy This can be demonstrated in the following manner: SET: RUN PRESS: 1 PRESS: 6 > 0 ; ” 3 " X>() ” 4 " 9 " 5 " GOTO(){) \" 5 " 9 V ; ” 0 ” 8 SET: | PROGRAM " 9 . 0 “ 7 7 8 " ENT EXP NOTE For a 9100B, use the (+) page for all examples. Pressing the STEP PRGM key will cause the contents of the 9 register to be displayed one character at a time in octal form. Character 9-0 9-1 92 93 94 95 96 97 98 99 9a 9b Bc Id Octal 00 11 #10 OF O06 O&O O04 O38 OF OF OF 06 10 OF Decimal 0 9 8 7 6 5 4 3 2 1 7 6 8 7 Display Dg Dy Dz Dz Dg Dg Og DZ Dg Dg Eg ©&; Gy G, This procedure loaded 12 significant digits into the 9 register. The demonstra- tion for a partial display produces quite different results: SET: RUN PRESS: 1 . 2 ” 3 . X>() ; ‘ ” GO TO()¢) ; a SET: PROGRAM 4 PSEUDO-HARDWARE PROBLEMS Pah a ae §100A/B PROGRAM STEPS o The STEP PRGM key will display the contents of the 9 register in octal form IN MEMORY 'y One character at a time. CHANGED TO e ¥+() OR ACC + _ Register 99 91 92 93 9-4 95 96 97 98 99 Sa Bb Bc Od (Continued) # Location ” Octal 40 40 40 40 40 40 40 O38 62 OF O02 00 40 40 iA Decimal : : - - - . : 3 2 1 2 0 2 Display Dg Dy Dg Dz D4 Dg Dg 97 Dg Dg Fo Fi Go Gy Z a In this example the octal code 40 is predominant, meaning an insignificant % zero which is blanked. Storing a negative number produces slightly different results, we SET: RUN PRESS: 1 " 2 ” 3 . CHG SIGN . X7¢) 9 “ GO TO ()() “ 8 “ 0 SEF: PROGRAM The STEP PRGM key will display the contents of the 9 register in octal form, one character location at a time. Register 99 9.1 92 93 94 95 96 97 98 99 9a Ob Oe Od Location Octal 40 40 40 40 40 40 40 O3 Q2 21 #O2 OO 40 40 Decimal - : - 3 2 1 2 0 Display Do 0; Da D3 Og D5 Og D7 Dg Dg Eg Ey Gg Gy In this example the octal code in location 9-9 contains a twenty bit, which means that the number is negative. If the CHG SIGN had been pressed first, still another example of a negative entry would have occurred. SET: RUN PRESS: CHG SIGN PRESS: 9 ” ' o 0 Fs " 2 SET: PROGRAM id GOTO()() PSEUDO-HARDWARE PROBLEMS 9100A/B The STEP PRGM key will display the contents of the 9 register in octal form, one character location at a time. Register 99 91 92 93 9-4 95 96 97 98 99 Ga Ob Oc Od Lacation Octal 60 60 @& 6 60 60 60 23 22 21 O2 OO 60 8 Decimal - : - - : : - 3 2 1 2 0 Display Do Dy Do D3 Dg Ds Dg D7 Dg Dg Eg E, Go Gy Pressing CHG SIGN first has loaded octal code 20’s in all of the digits. }f the digit was a blanked zero, it is an octal code 40; the two taken together result in octal code 60 which is a negative, blanked decimal zero. Now, back to the problem. The operator complained that after one pass through the program, steps previously containing program steps now contain Y >() instructions (octal code 40) or ACC + instructions {octal code 60). If he has stored a positive number with insignificant zeros over the register containing program steps, he has octal code 40's in the character locations that contain the insignificant zeros. If he has loaded a negative partial display over a register containing program steps, he has octal code 60’s in the characters not containing digits. With zeros in the X and Y registers and the DEGREES - RADIANS switch in | INCORRECT the DEGREES position, pressing TO POLAR will cause 90 and zero, respec- POLAR tively, to appear in the X and Y registers. Performing the same operation with CONVERSION the DEGREES- RADIANS switch in the RADIANS position will cause 1.570 796 326 00 and zero to appear in the Y and X registers. This occurs because of the algorithm used in the TO POLAR conversion, which is: ARC TAN v= 1) If the X and Y registers contained zeros, the calculator would divide zero into zero and obtain the instrument's interpretation of infinity (9.999 999 999 99). The ARC TAN of 9.999 999 999 99 is 90 degrees. 90 degrees in radians is 1.570 796 326 OO. Pressing two keys simultaneously will result in any of three occurrences: PRESSING TWO KEYS 1. The number in the X register will not change. SIMULTANEOUSLY Either key may be entered in the X register. Zeros will be entered in the X register. This is normat operation and requires no service action. AMBIGUOUS EQUALITY INCORRECT INT X KEY OPERATION DISPLAY CHANGES IF AN “IF” KEY IS PRESSED PSEUDO-HARDWARE PROBLEMS lr a . 9100A/B The “\F’ instructions compare all twelve digits (i.e. ten displayed digits and two guard digits) and the two-digit exponent, of the numbers in the X and Y registers when testing for the condition indicated. However, if a number consists of digit nine (9) in the first eleven places and (one of digits} five (5) through nine (9) in the twelfth place, then that number is considered to be equal to the next higher (more positive) power of ten. For example, 9.999 999 999 9(5 thru 9) x 102 = 10% similarly, 9.999 999 999 9(5 thru 9) x 10-2 = 107! Despite their equality to the next higher power of ten, those numbers which have unequal digits only in the twelfth place are not considered to be equal to each other. For example: 9.999 999 999 95 x 102 is not equal to 9.999 999 999 96 x 102. The rounding performed on the calculator display when the FLOATING - - FIXED: POINT switch is in the FIXED POINT position could lead an Operator to believe the INT X key is not functioning properly. For example, placing the number 5.9 in the X register and setting the DECIMAL DIGITS to O will cause the calculator to display six (6). If the INT X key is then pressed, the display will change to five (5). This occurs because the FLOATING - - FIXED POINT switch affects only the calculator display, not the number stored in the calculator’s internal register (which is always in floating notation}. Even though the calculator was displaying six (6), the internal registers were carrying the number as 5.9. When INT X was pressed the decimal part of the number (stored in the internal registers) was dropped, causing the calculator to display five (5). Pressing an “IF” key when a calculator is not running a program may cause the program counter to change location and, occasionally, may result also in a change of the display. This will occur because the calculator wil! process the key as though it were in a program and (depending on which “IF” key was pressed and the program steps tn the memory) process the next two instructions in the calculator’s memory or branch to the third following step and process it. The rule of thumb is: any “IF” key executed in this manner, will be executed as though the instruction were in the memory and encountered using the STEP PRGM key. PSEUDO-HARDWARE PROBLEMS S100A tf incorrect program steps (classically, octal code 77) are being loaded into the core memory (say, in the area of steps 2-1 thru 2-7) from a magnetic card, the program on the card may not have an END instruction. Some knowledge of the magnetic card reader operation is required to explain how this can happen. A —oe DATA TRANSFER BEGINS B TOTAL PROGRAM RECORDED~.. c { MEMORY Figure 3. A Program Recorded On A Magnetic Card When a magnetic card is recorded, the data transfer begins at point A in fig. 3. The program is fully recorded on the card at point B in fig. 3, but the recording will continue until the card is ejected. At C the unused memory is being recorded. At D the program counter reaches d-d and resets to 0-0. The recording process is uninterrupted and the beginning of the program its recorded again. When a magnetic card is entered in the calculator, the data transfer begins at point A (see Figure 3). The program is fully entered in the calculator memory at point B. At this time, had there been an END instruction on the magnetic card, the cardreader heads would stop reading the magnetic card. If, however, there were no END instruction, the cardreader heads would continue reading the balance of the card. At D, the program counter reaches d-d and resets to 0-0 and the cardreader heads continue reading the card. At the end of the magnetic card, as it is ejected from the cardreader, circuit switches, which sense the presence of the magnetic card in the cardreader, close. The cardreader heads, which are still sensitive, pick up the electricat noise of the circuit switches’ closure and transfer a bad instruction to the calculator memory. Shep te te fe. SAT AE eg et sa Onaga pee INCORRECT PROGRAM STEP LOADED INTO MEMORY FROM MAGNETIC CARD 10 PSEUDO-HARDWARE PROBLEMS SID0A KEYBOARD “The following instructions do not terminate a preceding digit entry in the OtGIT ENTRY 9100A: BECOMES A PART OF THE IF FLAG NUMBER IN THE eo SET FLAG X REGISTER 3 PAUSE i END a CHG SIGN x ENTER EXP Fa This characteristic of the 9100A operation can yield several different pseudo - é hardware problems. For example, here is one: is During diagnostic program execution, the PAUSE key is held pressed. an When the program stops, there will be a three (3) in the X register. If the ra digit key five (5) is pressed the X register wilt contain thirty-five (35). ey The way around this “problem” is, prior to making a digit entry, press any * key that will terminate digit entry, such as CLEAR X. PROGRAM Any of the foliowing instructions will initiate automatic program execution if EXECUTION they are encountered in the calculator memory with the STEP PRGM key STARTS WHEN when the calculator is in the RUN mode: STEP PRGM IS PRESSED CONTINUE PRINT/SPACE FMT CONTINUE - When STEP PRGM is pressed at this instruction the CONTINUE will override the STEP PRGM condition and automatically continue execution of the program. FMT and PRINT/SPACE - Both of these instructions are used to control peripheral equipment. When a program is running, the program stops at these instructions and waits for a “continue” signal from the peripheral equipment before continuing with the program. in the RUN mode, when STEP PRGM is pressed at either of these instructions, the “continue” signal from the peripheral equipment will cause the program to continue running. PSEUDO-HARDWARE PROBLEMS S100A To overcome the above situations: 1. Using the STEPPRGM key, step to (not through) the particular instruction. 2. Manually branch {using the GO TO) around the instruction (be sure to also branch around the instruction associated with a FMT). 3. Manually key the instructions that were skipped. The error lamp being lit when the calculator is switched ON is a normal = * operation and should be of no concern; provided, the light can be reset by pressing any key on the calculator keyboard. 1 TURNING CALCULATOR ON LIGHTS ERROR LAMP 12 UNUSUAL Z REGISTER DISPLAY UNEXPECTED RESULTS OBTAINED FROM OPERATIONS FOLLOWING “IF’’ INSTRUCTIONS PSEUDO-HARDWARE PROBLEMS 91008 Occasionally, when the PROGRAM- RUN switch is set to PROGRAM, an unusual display may appear in the Z register. This may consist of a random number between the address and the octal code; alternatively, an improper address or octal code, consisting of more than two digits, may appear. This display is the transfer vectors stored in the instrument when a subroutine is called. To clear it, switch to RUN and press the SUB/RETURN key; then, readdress the program counter to the required address and switch back to PROGRAM. The four conditional keys (IF FLAG, IFX<Y, IF X=Y, IF X>Y) are specifically intended to be followed by a branching address; therefore, in a few cases, unexpected results will be obtained if operational keys are substituted for the branching address. The following is a list of precautions that must be observed when using certain operational keys following “’IF’’ keys. Applicable to all four “IF’’ keys when the condition is met. 1. IFX=Y CHG SIGN Regardless of the steps preceding the “IF’’, changes the sign of the exponent of the number in X. The sign of the number remains unchanged. 2. IFX=Y e 1 If the program steps are on the (+) page: .1 + X If the program steps are on the (—) page: —.1 > X 3. IF X=¥ RCL The contents of {+) F are recalled to X, but the Y register remains unchanged; also, the program counter branches to a random address. Pages cannot be crossed without care. Any of the instructions listed below, if contained in the step following the “IF”, constitute the start of an address so that the next two steps must contain the remainder of the address: SUB/RETURN + any alphameric PSEUDO-HARDWARE PROBLEMS 51008 A CONTINUE cannot be used as a “no operation” in the step after an “IF” instruction, if it is followed by any one of the following: SUB/RETURN + any alphameric This is because the CONTINUE does not clear the “GO TO” condition set up when an “IF” jnstruction is met. For example, assume the following program steps are executed and the IF X = Y instruction is met: STEP KEY 2 tF X=Y 3 CONT 4 ~ 5 3 6 7 The program counter will branch to (—)3-7. Had the IF X= Y instruction been failed, the number 37 would have been entered in the X register. Applicable onty to the IF FLAG instruction when the flag is not set. STEP KEY 2 ENTER EXP 6 IF FLAG 3 4 any alphameric sa OO h WwW The “‘not met’ 'F FLAG does not reset the ENTER EXP instruction: this results in the alphameric character being entered as a digit of the exponent. If RCL is used in place of the alphameric, then the contents of F are recalled to X but nonsense appears in the Y register. STEP KEY 7 GO TO () () B CHG SIGN 9 2 10 3 Will send the program counter to (+)2-3 if the program counter is on the (—) page and to (—)2-3 if the program counter is on the (+) page. = x Ms. 13 UNEXPECTED RESULTS OBTAINED FROMA GO TO()()} INSTRUCTION 14 KEYSTROKES DO NOT APPEAR IN X SUBROUTINE CALLED FROM KEYBOARD WILL NOT RETURN CONTROL TO MAIN PROGRAM PRESSING STEP PRGM CAUSES MULTIPLE KEY EXECUTION PSEUDO-HARDWARE PROBLEMS 1” Roi aT oe re ates Bos “bs 2 gia d wae 9100B A 9100A program cannot be stopped (with the STOP key) during a GOTO(){) instruction; the 9100B can. To see how this can create a pseudo-hardware problem, consider the following example: STEP KEY 1 CLEAR 1 + PAUSE GO TO {)() Q 2 END an AO se WwW DN If the program is started and STOP is pressed to stop the program, the following two manual keyboard entries may not appear in the X register. This is because the STOP key will not work during PAUSE (where this program spends most of its time). The GOTO()() requires the second longest execution time and since the STOP will work during the GO TO()(), the odds are good that the STOP key will take effect there. If that is the case, the next two digit entry keystrokes are used to fill the “GO TO” address. If the STOP takes effect during any of the other program steps, the following digit entry keys will be entered in the X register. To avoid this situation, PRESS: STOP, STOP. If the program counter is addressed from the keyboard to the starting address of a subroutine and the CONTINUE key is pressed, then after the subroutine is completed, the program will not return to the correct address. This occurs because the transfer vector (return address) was never stored. Normally, a subroutine is called during program execution, which is when the transfer vector is stored; subroutines addressed from the keyboard have no way of returning to the main program. Occasionally, when in the RUN mode, pressing STEP PRGM once wili cause sev- eral keys to be executed. When STEP PRGM is pressed at a FMT instruction both the FMT and the next instruction will be executed as one instruction. The next time STEP PRGM is pressed, the second instruction after the FMT will be executed, The IF FLAG. X<Y, X= Y,X>Y will cause the program counter to branch immediately if the condition is not met and execute the third instruction following the quatifier. Prot PERFORMANCE ASSURANCE This procedure should be performed whenever a service call is made to repair a defective calculator. In this procedure, the 9100A Calculator is used as an illustration, 9100B differences that are meaningful to the procedure are noted. Equipment required: Hewlett-Packard Model 427A or equivalent. Calculator Service tool kit. 1. Turn the calculator power switch off and remove the power cable from the rear of the calculator. 2. Remove the two screws (four in the older models) from the bottom of the calculator and lift the cover of the calculator high enough to catch in the support latch near the back of the instrument. 3. Remove the screws (4) holding the keyboard (A in fig. 4), lift the keyboard out and disconnect the keyboard connectors (see fig. 5) from the calculator. B-2 B-3 B-3 A-3 A-4 (9100B) Figure 4. Location of Assembly Mounting Screws %. SE, ee 16 1 ene ‘SoA a se as KEYBOARD REMOVAL 15 16 PERFORMANCE ASSURANCE £ nie KEYBOARD BEZEL 4. Remove the screws (3) holding the keyboard (D in fig. 5) and remove y REMOVAL ; the bezel. 5. Remove accumulated dust and dirt from around the keys and thumb- wheel switch. ° 6. Reinstall keyboard bezel. KEYBOARD CONNECTORS KEYBOARD BOTTOM VIEW a: Figure 5. Keyboard Bezel Mounting Screws a ASSEMBLY Table 1. Assembly Mounting Screws MOUNTING REF | QTY | HP PART NO. | DESCRIPTION USE SCREWS . 4 0624-0246 Screw: Hex 6-32 x 1/2 Self Tapping . Al | 4 | 3060-0003 | Washer: No. 6 Fiber Keyboard B-1 1 0624-0244 Screw: Hex 6-32 x 1/4 B-2 3 0624-0246 Screw: Hex 6-32 x 1/2 Self Tapping A20 3 0624-0249 Screw: P/H pozi 6-32 x 1/2 Tapping Power Supply 3 3050-0026. | Washer: Brass, .43750D, .1251D Ass’y B-3 3 2190-0017 Washer: No. 8 Lock 3 3050-0221 Washer: Shoulder, Fiber, .1721D 80D, .095thk 2 2420-0002 Nut: Hex 6-32 x 1/4 C-1 2 3050-0066 Washer: No. 6 Flat 2 2190-0918 Lockwasher: Helical Spg, Heavy V1 Ass'y C2 2 0624-0248 Screw: Hex 8-32 x 3/4 Self Tapping 2 3060-0278 Washer: No. 8 Fiber 3 2200-0006 Screw: Common 4-40 x 3/8 D-1 3 2190-0003 Washer: No. 4 Lock Keyboard Bezel 3 3050-0026, Washer: No. 4 Flat 3 2360-0013 Screw: Common 6-32 x 1 E-1 3 2190-0003 Washer: No. 6 Flat Keyboard Bottom 3 | 2190-0018 | Washer: No. 6 Lock Plate F-1 4 2360-0197 . | Screw: P/H pozi 6-32 x .375 Cardreader Ass’y G-1 5 0624-0246 Screw: Hex 6-32 x 1/2 Bottom Ass’y G2 4 2360-0197 Screw: P/H pozi 6-32 x .375 PERFORMANCE ASSURANCE ry 7. Remove the screws (4) holding the cardreader (F in fig. 6), and lift the ° cardreader. out. 8. Fold a 9160A input card in half tengthwise; saturate one end of the #8, card with magnetic head cleaner (-hp- P/N 8500-0810) from the service kit. Slide the card: in and out of the cardreader slot several times. 3 Moisten a tissue with the head cleaner and clean the cardreader wheel. Tighten the set screw in the cam on the cardreader motor. Reinstall the cardreader. CAUTION THE CARDREADER MUST BE REMOVED FROM THE INSTRUMENT WHEN THE HEAD CLEANER IS USED BECAUSE IT WILL DISSOLVE THE PLASTIC BEZEL. Figure 6. AS and A40 Assembly Mounting Screws CAROREADER REMOVAL 17 PERFORMANCE ASSURANCE 9. Remove the Al, A? (2), A3 and A4 (Al, A2 (2), A3-A4 for a 9100B) assemblies (see Fig. 7). Clean the connectors of each assembly and oe reinstall. : NOTE The board pullers are color-keyed to match the card guides. 10. Reinstall the keyboard. gt C7} y : s , Awe | A20DS2 Othe AE A20DS1 4 ps FOCUS ADJ INTENSITY sa A20DS _ c 3 ADJ ih Vv & 1 A21TP1 AIS e A21 Qe ce Al6 yy A20 i A3-A4 é -3400V (9100B) is 2 A A20327 A a A4 Lh : Al au A3 5 A5 & BOTTOM am A40 fe CARD KEYBOARD READER c i e Figure 7. Assemblies of the 9100A/B Potaad “ ix PERFORMANCE ASSURANCE onan. cane 11. Remove the chain from the kit and install (see fig. 8). Push the support latch in and fet the cover back against the chain. CAUTION DON’T FLIP THE TOP ALL THE WAY BACK; !T WILL GOUGE THE REAR CONNECTOR AND MAY SCRATCH THE TOP. 12. Remove the vertical amplifier (A16 in fig. 7), clean the connector, tighten the pin connectors and reinstall. Reconnect the wiring. White/Black .. 0... cc eect ee eee cere eee tenes up White/Red 2.0... ccc ccc cee eee ee eect eee eee eee down 13. Remove the horizontal amplifier (A15 in fig. 7), clean the connector, tighten the pin connectors and reinstall. Reconnect the wiring. White/Orange ..... 00... 0c cc cc ce ee eee ences right White/Brown ..... 0.0.00. ccc ce ee ee cee eee n eee left 19 SERVICE CHAIN INSTALLATION 20 A20A2T1 LEAD DRESSING PERFORMANCE ASSURANCE 14, 15. Remove the —15V power supply (A21 in fig. 7). Remove the screws (7) (B in fig. 4) holding the power supply assembly. Lift the power supply assembly and turn it on its side. CAUTION THE TOP OF THE CALCULATOR MUST BE SUPPORTED WHEN THE POWER SUPPLY MOUNTING SCREWS ARE LOOSENED; IF NOT, THE CALCULATOR WILL TIP BACKWARD. byeyesra: ot 16. 17. 18. 19. 20. 21. 22. 23. 24. Clean the underside of the power supply assembly. Before installation, make sure the output lead of the high voltage transformer comes straight out of the transformer. If it is left too close to the transformer, it will arc (see fig. 9). ¢ '® ® 3 =o —-c1—_ 5 DRESS LEAD . — AWAY FROM § Tv 'S) TRANSFORMER c — | S ra : so ' | Fg Cem ao —cr— © § & {ij RW js” 8 Figure 9. The A20A2 Assembly Reinstall the power supply assembly. Clean the contacts of the —15V power supply assembly and reinstall. Tighten all screws and bolts on the calculator. Pull the top of the calculator into its normally open position and remove the chain. Reconnect the power cord and turn the calculator on. Measure —15V +/---5V at A21P1 (fig. 7) using -hp- 427A. Adjust A21R13 (—15 volts). Measure from center pin of A21R19 (HV) to ground. Adjust A21R19 for reading of +27.4VDC +/—.3V. Enter minus one in the X register and take the square root of it. The error light should light; if it does not, check the error light. Sets ane PERFORMANCE ASSURANCE od 25. Enter 8's in the X, Y and Z registers. 8 26. Adjust the intensity and focus located on the power supply assembly s (A20) for a sharp, bright display on the CRT. a CAUTION HIGH VOLTAGE. USE INSULATED SCREWDRIVER. vane’ ga a3 Se bee ine i 27. Adjust the: (Vertical Amplifier A16) (Horizontal Amplifier A15) Register Separation Register Length 3¢ Character Height Right E Adjust : Vertical Position Horizontal Position « on the horizontal and vertical amplifiers for a display similar to Fig. Fe 10. : Shee z treme e =~ mo Ad X keyboard a Figure 10. A Properly Adjusted CRT Display SAR 28. Close calculator cover. CAUTION ALL BOARDS MUST BE INSERTED COMPLETELY INTO . THEIR CONNECTORS. DAMAGE TO OTHER BOARDS COULD RESULT IF ALL BOARDS ARE NOT PROPERLY SEATED. WHEN PROPERLY SEATED, THE BOARD’S EXx- TRACTOR WILL BE IN AN UPRIGHT POSITION. 29. Clean the calculator case with a soft, damp cloth. 30. Clean the display bezel with a soft cloth dampened with the cleaner provided. CAUTION NO OTHER TOOLS OR METHODS OF CLEANING SHOULD BE ATTEMPTED AS THE DISPLAY BEZEL IS EASILY SCRATCHED. 31. Check magnetic cardreader by entering a program from a magnetic card into the calculator’s memory and recording that program on another magnetic card. DISPLAY TEMPLATE 21 22 PERFORMANCE ASSURANCE NOTE The card cannot be recorded it its corner is clipped 32. Check digit entry and arithmetic section of keyboard by pressing the keys shown: SET: DEGREES FLOATING RUN KEYS DISPLAY T 3.141 592 653 00 9,.9,VXx.- 9,949 874 371 00 33. Check control, storage and recall sections of keyboard by pressing keys shown: NOTE a Calculator algorithms are performed in floating notation. Due pape . to possible error in the twelfth place, the calculator display has aeale 3 a +/—1 count tolerance. KEYS ° DISPLAY 3,5,sinx 5.735 764 363 -01 arc, sin x 3.499 999999 01 “ 3, 5, cos x 8.191 520 442 -01 arc, COS x 3.499 999999 01 3, 5, tan x 7.002 075 381 -01 anion ane arc, tan x 3.499 999999 01 oP tgs 5, hyper, sin x 7.420 321057 01 ~y arc, hyper, sin x 5.000 000 000 00 5, hyper, cos x 7.420 994 852 01 arc, hyper, cos x 5.000 000 000 00 4, hyper, tan x 9.993 292 997 -01 arc, hyper, tan x 4.000 000 000 00 3, eX 2.008 553 692 01 5,0, In x 3.912 023005 00 5, 0, log x 1.698 970 004 00 34. Check INT X, IYI, ACC +, ACC —, RCL: SET: FIXED POINT SET: DECIMAL DIGITS to 3 Press CLEAR, enter 123.456 in the X register. Press the INT X key. The X register should now have 123 in it. Press the — key, the Y register now has —123 in it. Press |Y|, the display in the Y register changes to 123. Press CLEAR, 7, t, ACC +, then ACC -, then RCL. The X and Y registers should contain zeros. a PERFORMANCE ASSURANCE 35. Check rectangular to polar to rectangular conversion: SET: FLOATING Enter 3 in the Y register and 4 in the X register, press TO POLAR: 3.686 989 764 01 should appear in Y 5.000 000000 00 should appear in X Press TO RECT: 2.999 999 999 00 should appear in Y 4.000 000 000 00 should appear in X For 9100B go to STEP 38 36. Replace screws in the bottom of the calculator. 37. Enter and run diagnostic program. 9100B ONLY 38. Check x « () x«() 2 The X and Y registers should contain 7, 39. Check the subroutine nesting: A. PRESS: END, GO TO () (), SUB RETURN, 1, 0 SWITCH: PROGRAM The Z register should display 1.0 ---- XX NOTE The XX may be any number. B. SWITCH: RUN PRESS: GO TO ()(), SUB RETURN, -, 2, 0 SWITCH: PROGRAM The Z register should display —2.0 --- XX C. SWITCH: RUN PRESS: GO TO (}(), SUB RETURN, +, 3, 0 SWITCH: PROGRAM The Z register should display 3.0 ---- XX 23 24 PERFORMANCE ASSURANCE D. SWITCH: RUN PRESS: GO TO ()(), SUB RETURN, 4, 0 ae SWITCH: PROGRAM x The Z register should display 4.0 --- XX E. SWITCH: RUN PRESS: GO TO (){), SUB RETURN, 5, 0 SWITCH: PROGRAM = The Z register should display 5.0 ---- XX F. SWITCH: RUN PRESS: SUB RETURN SWITCH: PROGRAM The Z register should display 4.0 ---- XX G. SWITCH: RUN PRESS: SUB RETURN SWITCH: PROGRAM The Z register should display 3.0 ---- XX H. SWITCH: RUN PRESS: SUB RETURN SWITCH: PROGRAM The Z register should display —2.0 --- XX 1. SWITCH: RUN PRESS: SUB RETURN SWITCH: PROGRAM The Z register should display 1.0 ---- XX J. SWITCH: RUN ; PRESS: SUB RETURN SWITCH: PROGRAM The 2 register should display 0.0 ---- XX SWITCH: RUN 40. Enter and run diagnostic program. 41. Replace screws in bottom of the calculator. TROUBLESHOOTING When a calculator performs an operation, the signals required for that operation flow in a loop through all the calculator’s assemblies. If one assembly is defective, the loop is broken and the calculator will not work. The service kit allows substitution of assemblies into the loop until the defective assembly is replaced by a good assembly, thereby, restoring the calculator to operation. NOTE Prior to making a calculator service call, install your kit assemblies in a known-good calculator and check them for proper operation. Prior to troubleshooting a calculator, ensure the calculator is defective; run the diagnostic program and, if possible, have the operator show you the trouble. This may not be necessary if the failure is catastrophic (e.g. no display) but always do this if the calculator appears to be functioning normally; the problem may be intermittent or associated with manual operation (e.g. 7 key sticks). Always check for a pseudo-hardware problem. Raise the calculator cover and, while listening carefully, shake the CRT. If it rattles, elements in the CRT may be shorting and may have already destroyed the horizontal and/or vertical deflection assemblies along with the bottom assembly. If these assemblies are replaced with kit assemblies, without the CRT being changed, the kit assemblies may also be destroyed. This type of CRT failure is caused by a physical shock which breaks the glass electron gun support rods. If the horizontal or vertical deflection plates then touch a grounded element in the CRT, 220 volts will be routed into the bottom assembly by the horizontal or vertical deflection assembly (depending on which deflection plate was grounded); this 220 volts will do extensive bottom assembly damage. Here are the symptoms for broken vertical deflection plate support rods: 1. A sudden downward shift in the calculator display has occurred sometime in the past. (This may have been temporarily corrected by adjusting the vertical Position Adj (A16R22)). 2. The calculator has no vertical deflection in any register. 3. The CRT rattles, particularly when the top case is raised. Here are the symptoms for broken horizontal deflection plate support rods: —_ A sudden change in the horizontal position of the display. N No horizontal deflection in any register. The CRT rattles. w STEP 1 VERIFY THE PROBLEM STEP2. CHECK THE CRT 25 26 STEP2 CHECK THE CRT (Continued) STEP 3 TROUBLESHOOTING TREE THE INTERMITTENT CALCULATOR TROUBLESHOOTING lf one or more of the above symptoms are present, replace the CRT and the Horizontal or Vertical deflection assembly (whichever is applicable), before replacing any other calculator assembly. This problem must not be confused with the change in display caused by changing the calculator’s location; that is caused by the CRT being affected by the earth’s magnetic field. In this problem, the display is usually tilted and is fixed by loose