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Click here for further information on our rarity scale RARITY: Exceedingly Rare Information on the rarity of this item is unknown.

 YEAR: late 1950's
 COMPANY: Donner Scientific Company

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Donner Analog Computer Model 3500

A view of the vintage Donner Analog Computer Model 3500 an important part of computer history
The Model 3500 is a unique portable, analog computer. Weighing just 28 pounds and sporting two leather handle straps (one at each side) the 3500 was designed for use by scientists and engineering designers who could easily move the computer from one place to another. It could be used as a versatile signal generator, data reduction or signal conditioning at test sites, and as a general purpose computer in the classroom, field, or desk. Use for the classroom was convenient with 2 detachable problem boards controlling half the computer. There is a remote control for field testing. It was probably first offered for sale in the late 1950's. It was designed so that it could be a free-standing computer or it could be reconfigured to be rack mounted. The one in our collection is slightly different from those pictured in the "Instruction Manual Model 3500" in that it has a protruding, angled front control panel. We don't know if this is a standard factory version of the 3500 or a later customization.

How did you operate it?

Operating this computer wasn't easy. The Instruction Manual states that the 3500 should "warm up for at least ten minutes" before use. In addition, the manual recommends "a daily or weekly check should be made of the +300V and -150V power supply output voltages." [So don't complain next time your computer takes 30 seconds to power up!]

Porgramming was done by patchcords. This means that is you wanted to program the analog computer to solve an equation you had to configure the patchcords in just the right way. And if you then wanted to solve another equation...you had to unplug all the patchcords and reconfigure them. Imagine having to use patchcords instead of your keyboard or mouse or touchpad to enter information into your computer.

History of the Donner Scientific Company

Donner Scientific Company was founded in 1953 in Berkeley, CA by William Rosenberry and was named after Donner Pass. The company moved to Concord, CA in 1954. They began making the Model 30 Analog Computer (a vacuum tube computer) and sold 600 units between 1954 and 1960. Donner Scientific merged with Systron Corp. to become Systron Donner Corp. on March 31, 1960.

Systron Donner is still in existence in the same city. They are called "Systron Donner Interial" and make sensing devices (such as gyroscopes) for all sorts of modern tecnologies such as the Mars Rover (really, they are on Mars!), military helicoptions, UAVs, torpedoes and robots.

Related Items
      Related Item 1: Donner Problem Board

Viewer Stories & Comments
   Andrew Davie     Hobart, Australia     March 26, 2015

       I have a Datanumerics DL-8A front panel blinking-lights computer from about 1976. It's the only one I know of still in existence. Just thought I'd make it known that there is one, and it still works :)

Copyright © 2017 by Early Computers Project, All Rights Reserved.

Click on any of the images below to see the slideshow. Front view of the Donner 3500 analog computer.  This rare analog computer was designed for engineers and teachers. Front and top view of the Donner 3500 analog computer.  The wires (called patchcords) were used to program the computer; imagine substituting that wiring process for the modern keyboard. View of the left side of the Donner 3500 analog computer -- notice the leather strap handles & angled front panel.  Right side view of the Donner 3500 analog computer -- patchcords have been removed. Back of the Donner 3500 analog computer.  You can see the manufacturer's tag and some extra large holes to let the heat dissipate. Closeup of the manufacturer's tag that includes the serial number.  You can also clearly see the company's name.  Later versions of this classic analog computer display the name Systron-Donner after the companies merged in 1960. View of the back of the Donner 3500 analog computer which opened easily for access to cards and tubes.  The tubes of an analog computer generated quite a bit of heat.  Closeup of the opened back of the Donner 3500 analog computer.  Note voltage range of +/- 100 printed on the frame just above the tubes. Closeup of the Donner 3500 analog computer patchboard from the top. Closeup of the Donner 3500 analog computer's patchboard from the front.  This is the same section of the patchboard shown in the previous picture. A view of the underside of the the Donner 3500 analog computer's patchboard.  You can also see the fan (covered by a screen) and the oblong openings that were used to dissipate the heat from the tubes. Closeup of right side of the Donner 3500 analog computer control panel.  This rare portable analog computer was an important part of computer history.
(Analogs in blue)
  1. AIM-65 (single board)
  2. AIM-65 (factory case)
  3. AIM-65 (Jon Titus)
  4. ALICE micro-ordinateur
  5. Altair 680
  6. Altair 8800
  7. Altair 8800A
  8. Altair 8800b
  9. Altair 8800b Turnkey (see Pertec below)
  10. Altair 8800b (see Pertec below)
  11. Altair 8800b w/ Hardisk
         Controller & Datakeeper
  12. Altos ACS-8000
  13. American Basic Science Club Analog Computer
  14. AMF Educational Computer
  15. Apple II Plus
  16. ASCI SystemX
  17. ASR 33 Teletype
  18. Automatic Teaching Computer Kit
  19. Beckman ElectroComp Electric Heating Computer
  20. Beckman Solid State Fuel Cost Computer
  21. Brainiac K-30
  22. Calif. Computer Systems 2200
  23. CES Ed-Lab 650
  24. Commodore 8032
  25. Commodore 64
  26. Commodore PET 2001
  27. Commodore Super Pet
  28. Compucolor II
  29. Compukit 1
  30. Compukit 1 Deluxe Model
  31. Compukit 2
  32. Compukit UK101
  33. Comspace CT-650
  34. Cosmac Elf (RCA1802)
  35. Cosmac Microtutor
  36. Cosmac Netronics ELF II
  37. Cosmac VIP
  38. Cromemco System I
  39. Cromemco System III
  40. Cromemco Z-2D
  41. Datapoint 2200
  42. Digi-Comp I (flat box)
  43. Digi-Comp I (square box)
  44. Digital Computer Lab
  45. Donner 3500
  46. Durango F-85
  47. Dynabyte
  48. E & L Inst MMD-1
  49. E & L Inst MMD-2
  50. Eagle II
  51. Electric Tabulating Machine (one original counter, 1889)
  52. Electronic Associates Inc. TR-10
  53. Electronic Associates Inc. TR-10 Model II
  54. Electronic Associates Inc. TR-20
  55. Electronic Associates Inc. TR-48
  56. Electronic Associates Inc. TR-48
  57. Electronic Associates Inc. Model 180
  58. Electronic Associates Inc. Model 380 Hybrid
  59. Geniac
  60. Google Glass (definitely not vintage)
  61. Heath EC-1 (factory assembled by Heath)
  62. Heathkit EC-1 (kit)
  63. Heathkit ET 3100 trainer
  64. Heathkit H8
  65. Heathkit H9 Video Terminal
  66. Hickok Logic Teaching Sys.
  67. Hickok Servo Teaching Sys.
  68. HP 2115A
  69. HP 85
  70. HP 5036A
  71. HP 9825A
  72. HP 9825B
  73. HP 9830A
  74. Iasis 7301
  75. I-COR MAC-1
  76. ICS Microcomputer Training System
  77. IMSAI 108 (prototype)
  78. IMSAI 8048 Control Computer
  79. IMSAI 8048 (The Dollhouse Computer)
  80. IMSAI 8080
  81. IMSAI PCS-40
  82. IMSAI PCS-80
  83. IMSAI VDP-80
  84. Informer
  85. Intel Intellec MDS
  86. Intel MDS-800
  87. Intel Prompt 48
  88. Intel SBC 80/10
  89. Intel SDK-85
  90. Intel SDK-85 (unassembled)
  91. Intel SDK-86
  92. ITT MP-EX
  93. JR-01 Computer
  94. KIM-1
  95. LAN-DEC
  96. LAN-DEC 20
  97. LAN-ALOG
  98. Lehrcomputer (Germany)
  99. Lawrence Livermore Lab
  100. Lear Siegler ADM3A
  101. Logikit LK255 (Feedback)
  102. Logix SF-5000 Electronic Computer
  103. MAC-1 Mini Analog Computer
  104. MAC Tutor (Bell Laboratories)
  105. MEK6800D2
  106. Micro 68
  107. Microtan 65
  108. Midwest Scientific Instruments 6800
  109. Minivac 601
  110. Minivac 6010
  111. Mini-Scamp Microcomputer
  112. Nascom I
  113. Nascom II
  114. National Radio Institute 832
  115. NEC TK-80
  116. NorthStar Horizon
  117. Olivetti Programma 101
  118. Olivetti Programma 203
  119. Olivetti Programma 602
  120. Open University PT501
  121. Ordinateur d'Apprentissage JR-01
  122. Osborne 1
  123. OSI 300
  124. OSI 600 (SuperBoard II)
  125. OSI C2-OEM-4
  126. OSI Challenger-1P
  127. Pastoriza Personal Analogue Computer
  128. Pertec MITS 300/25 (Altair desk business system)
  129. Pertec MITS 300/55 (Altair Turnkey business system)
  130. PolyMorphic Systems 8810
  131. PolyMorphic Poly-88
  132. Protech-83
  133. Range Keeper Mechanical Analog Computer, 1936?
  134. Sargent-Welch Scientific Company Cat. No.7528 Analog Computer
  135. Science of Cambridge MK-14 (Sinclair)
  136. SD Systems Z80 starter kit
  137. Sharp MZ-40K
  138. Sharp MZ-80k
  139. Siemens ECB-85
  140. Signetics Instructor 50
  141. Smoke Signal Broadcasting
  142. Sol-20
  143. Spark16
  144. Sphere 1
  145. Sphere/SWTPC Computer System
  146. SWTP CMOS Microlab
  147. SWTP CT-82 Terminal
  148. SWTPC 6800
  149. SWTPC 6800 (w/ Smoke Signal Broadcasting drive)
  150. SWTPC CT-64 Video Terminal, SS-50
  151. SWTPC TV Typewriter II CT-1024
  152. Synertek VIM-1
  153. Synertek SYM-1
  154. Systron-Donner 3500
  155. Tei MCS-112
  156. Tektronix 4006-1
  157. Telefunken RAT 700
  158. TI LCM-1001 (Microprogrammer)
  159. TI LCM-1001 (Microprogrammer)
  160. TI Silent 700 Terminal
  161. TI TM 990/189
  162. Vector 1
  163. Vector 3
  164. Wang 2200
  165. Welch Scientific Company Cat. No.7528 Analog Computer
  166. Xerox 820 Mark I
  1. Chameleon Plus
  2. Commodore SX64
  3. Epson HX-20
  4. Kaypro I
  5. Kaypro II
  6. Kaypro 2x
  7. Kaypro 16
  8. Osborne 1
  9. Panasonic Senior Partner
  10. Visual Commuter
  1. Babbage's Calculating Engine (1834)
  2. Electric Tabulating Machine (1889, Herman Hollerith's personal copy)
  3. The Hollerith Electric Tabulating System (1890)
  4. Counting a Nation by Electricity (1891)
  5. Moore School Lectures Vol. II (1947)
  6. Mathematical Theory of Communication (1948)
  7. Communication Theory of Secrecy Systems (1949)
  8. The "Moore's Law" article (Electronics, 1965)
  9. Printout from Babbage's Difference Engine #2 (London Science Museum, 2004)