Hewlett Packard HP-35

 
Serial Number (1) 1402S07720: 1974, 2nd week, Singapore
Accessories Protecting box (one latch ripped off), dirty

Power supply

Manual: HP-35 Bedieningshandboek (Dutch language), worn front and back page

Manual: HP-35 Bedienungshandbuch (German), bound printout from the MoHPC CD-ROM
Condition Optically pretty good, some very small scratches on the display, front-side needs in-depth cleaning. 
For repair I cut two holes in back label to reach the screws. Unit had never been disassembled before, back label was intact. 
Functional problems: Bouncing keys, 1 segment of the 9th display digit from left doesn't work.
Repairs, Comments 8.7.2002 Opened the unit: Looks good inside. However, I could neither fix the bouncing keys nor the missing display segment. Actually, because of the scanned nature of the display and only one segment missing this is caused most likely not by a bad solder joint or driver chip but rather a defective display. 
Because of these problems the calculator is not really usable.
This is a version 3 model.
Acquired 30.6.2002
Serial Number (2) 1143A33381: 1971, 42rd week, America
Accessories None
Condition Excellent! Some wear of the silver lining around the on/off switch and around the bottom HP label
Repairs, Comments This is a version 2 model.
Acquired 17.3.2003
.
HP codename, series Unknown, Classic
Type, Precision, Input Mode Scientific, 10 BCD digits, exponent 99, Reverse Polish Notation.
Delivers not very accurate results. Apparently uses the same software than the HP-25 because the errors are identical.
Programmable No
Memory 1 register, not permanent
Display 13 digit 7 segment red LED plus sign
Special features Different from the normal yx function this model uses a xy notation.
Original Pricing, Production 1.7.1972 ($395) - 1.2.1975 ($195), $293 when HP-45 was introduced
Batteries Battery pack with 3x AA sized cells or power supply. 
Can be operated with AC adapter and no batteries installed.
Dimensions Length 15.1cm, Width 8cm, Height 3.6cm
Links HP-35 Operating Manual (PDF)
HP-35 Math Pac, 1974 (PDF)
HP-35 Suveying Pac (PDF)
HP-35 Taschenrechner Bedienungsanleitung, April 1973 (PDF, German)
HP-35 on Wikipedia.
Comment Hewlett Packard's first pocket calculator. First calculator ever using RPN entry mode. 
A very basic device from today's perspective. See also HP-35s. Other companies tried to produce similar calculators, see Melcor SC-535.
Apparently, there were 4 models of the HP-35:
  • The 1st one had a red dot to the right of the on/off switch that showed when the unit was turned on.
  • The 2nd version didn't have the red dot nor the "35" printed on the bottom next to the "Hewlett Packard" brand name.
  • The 3rd version had the "35" added right of the brand name on the bottom label.
  • The 4th version had the labels for function keys molded directly on the top of the keys rather than above the keys.

Legend has it that the calculator's name refers to its 35 keys.
In 2007, 35 years after the introduction of the HP-35, Hewlett Packard released a successor, the HP-35s.



Calculation (HP-35)
Correct result
HP-35(2) Result
Error
100/18 
40/9 
5.555555*0.5555555
40/9+50/9000 
sqrt(2E6)/1000
exp(0.005) 
exp(0.999999) 
exp(1.000001) 
exp(100)/1E43
ln(1E-6)/10
ln(0.9995)*10000 
ln(1.0005)*10000
pow10(0.005) 
pow10(0.99999) 
pow10(1.00001)/10 
pow10(80.1)/1E80 
log10(2E-8) 
log10(0.9995)*10000 
log10(1.0005)*10000 
log10(1000100) 
2^40 / 1E12 
2^1.443 
1.000001^1E6 
sin(0.01 rad)*1000 
sin(1 rad)*10 
sin(1.5608 rad)*10 
sin(800 rad)*10 
tan(0.01 rad)*100 
tan(1 rad) 
tan(1.5708 rad)/1E5 
tan(800 rad) 
asin(0.01)*100,rad 
asin(0.5)*10,rad 
asin(0.999),rad 
asin(0.99999),rad
atan(0.01)*1000,rad 
atan(0.9999)*10,rad 
atan(1.0001)*10,rad 
atan(1E4),rad 
sin(0.01 deg)*10000 
sin(50 deg)*10 
sin(89.9 deg)*10 
sin(5000 deg)*10 
tan(0.01 deg)*10000 
tan(50 deg) 
tan(89.99 deg)/1000 
tan(5000 deg)*10 
asin(0.01 deg)*10 
asin(0.5 deg)/10 
asin(0.999 deg)/10 
asin(0.99999 deg)/10
atan(0.01 deg)*10 
atan(0.9999 deg)/10 
atan(1.0001 deg)/10 
atan(1E4 deg)/10 
+5.555555555 555555556
+4.444444444 444444444
+3.086419135 802500000
+4.450000000 000000000
+1.414213562 373095049
+1.005012520 859401063
+2.718279110 178575917
+2.718284546 742232836
+2.688117141 816135448
-1.381551055 796427410
-5.001250416 822979193
+4.998750416 510479141
+1.011579454 259898524
+9.999769744 141629304
+1.000023026 116026881
+1.258925411 794167210
-7.698970004 336018805
-2.172015458 642557997
+2.170929722 302082819
+6.000043427 276862670
+1.099511627 776000000
+2.718856483 813477575
+2.718280469 319376884
+9.999833334 166664683
+8.414709848 078965067
+9.999500371 413582332
+8.939696481 970214179
+1.000033334 666720637
+1.557407724 654902231
-2.722418084 073540959
-1.994900160 845839293
+1.000016667 416711313
+5.235987755 982988731
+1.526071239 626163188
+1.566324187 113108692
+9.999666686 665238206
+7.853481608 973649763
+7.854481608 975316429
+1.570696326 795229953
+1.745329243 133368033
+7.660444431 189780352
+9.999984769 132876988
-6.427876096 865393263
+1.745329269 716252907
+1.191753592 594209959
+5.729577893 130590236
-8.390996311 772800118
+5.729673448 571526491
+3.000000000 000000000
+8.743744126 687686209
+8.974376527 084057279
+5.729386976 834859268
+4.499713506 778012245
+4.500286464 574097998
+8.999427042 206779036
+5.555555556
+4.444444444
+3.086419136
+4.450000000
+1.414213562
+1.005012521
+2.718279110
+2.718284547
+2.688117141
-1.381551056
-5.001250000
+4.998750000




-7.698970003
-2.172015278
+2.170929541
+6.000043426
+1.099511625
+2.718856482
+2.718281828
















+1.745328987
+7.660444432
+9.999984769
-6.427876027
+1.745329013
+1.191753592
+5.729569869
-8.390996161
+5.729673428
+3.000000001
+8.743744128
+8.974376526
+5.729386976
+4.499713507
+4.500286465
+8.999427042
0
0
0
0
0
0
0
0
   1E-9
0
 416E-9
 416E-9




   1E-9
 180E-9
 181E-9
   1E-9
   3E-9
   2E-9
1359E-9
















 256E-9
   1
E-9
0
  69E-9
 256E-9
   1E-9
8024E-9
 150E-9
  20E-9
   1E-9
   1E-9
   1E-9
   1E-9
0
0
0

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