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What was the first personal computer?

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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: 1917
 COMPANY: Ford Instrument Co., Inc.
 COUNTRY: USA
 IN OUR COLLECTION: Yes
 

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Time of Flight Clock

 

The "Time of Flight" clock was a part of the US Navy's first computer (later called a Range Keeper), the Mark I which performed a remarkable number of continuous functions in real time for a computing system in those days. The Mark I Computer was later referred to as the Range Keeper Mark I.

The "Time of Flight" clocks were used in the U.S. Navy in WWI. The clock was started when one of the "big guns" fired on an enemy target and an alarm was sounded about 2 seconds (according to the patent description) before the shell was supposed to hit the enemy target. A gunnery officer would look for the explosion or the splash (if the shell missed...which was roughly 9/10 times) and would adjust the guns accordingly. This clock was part of the Mark 1 computer that was used to aim the ship's guns on enemy targets. The label on the clock is clearly marked Mark I and Model 1 with Serial No. of 212. (The Time of Flight Clock in our collection is a bit earlier than the one in the Smithsonian Museum -- Serial No. 283. The Smithsonian also has an error in their description...saying that the central dial "runs from 0 to 20" when it actually runs from 0 to 18.)

The patent for the "Time of Flight" clock was applied for in 1918 and granted in 19201. We have given it the date of 1917 because it was being tested in 1916 and then installed on battleships (see just below) in 1917. The clock was an integral part of Mark I computer that was tested on the USS Texas in the summer of 1916. According to Mindell's examination of the history of computing, the Mark I computer was installed on the battleships, USS New York, USS Wyoming, USS North Dakota and the USS Pennsylvania in 1917.2

The central dial was used to set the clock. The numbers around the dial stand for the number of yards to the enemy target! Stamped around the dial are the words, "YARDS 5" - 2600 F.S.". The central dial is a measurement of yardage to the enemy target and is set up for 5" guns that are designed to fire with an initial velocity of 2600 feet per second (F.S.). The maximum yardage for these guns was 18,000 yards and you can see that 18 is the max number on the dial.

This particular "Time of Flight" clock looks to have been updated by the US Navy. Originally, this clock would have had two electrical terminals just to the right of the main dial. Those two terminals would have allowed an electrical alarm device to be added to the clock...basically a peripheral device! As the patent application puts it, "If desired, an electrical alarm device may be ultilized which comprises two spring contacts ...which are normally out of engagement." The application goes on to state that the two terminals "are provided with sockets to receive jacks or plugs, which would be connected by wires to any suitable annunciator."1 Those two terminals were replaced with a single electrical input (you can see outline of the now unused second terminal just below it.) So even as early as 1916, Ford was anticipating the use of electricity for his computing devices. Around the central dial, stamped into the metal, is "O.P.551 - SEPT 1933 MKI-1" which suggest the update was made in 1933.

1United States Patent and Trademark Office. Patent# 1,355,829. View Patent

2Mindell, David. "Between Human and Machine: Feedback, Control, and Computing Before Cybernetics." Johns Hopkins University Press, April 30, 2003.

Clymer, Ben A. “The Mechanical Analog Computers of Hannibal Ford and William Newell.” IEEE Annals of the History of Computing, vol. 15, no. 2, 1993, web.mit.edu/STS.035/www/PDFs/Newell.pdf.

https://ieeexplore.ieee.org/abstract/document/207741


Related Items
      Related Item 1: Range Keeper Mark VI





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IMAGES
Click on any of the images below to see the slideshow. Top View of TOF Clock with chain Close up of top Top View of TOF Clock Side view of TOF Clock label Side view of Clock with chain Side view with Label Clock upside down in order to clearly see Label Close up of Dial Stop - Start Button Electric Terminals Alarm set The Winding knob (power unit!) Bottom of clock Copy of patent (page 1)
COMPUTER COLLECTION LIST (PRE-1981)
(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 ElectroComp Energy Savings Computer
  21. Beckman Solid State Fuel Cost Computer
  22. Brainiac K-30
  23. Calif. Computer Systems 2200
  24. CES Ed-Lab 650
  25. Commodore 8032
  26. Commodore 64
  27. Commodore PET 2001
  28. Commodore Super Pet
  29. Compucolor II
  30. Compukit 1
  31. Compukit 1 Deluxe Model
  32. Compukit 2
  33. Compukit UK101
  34. Comspace CT-650
  35. Cosmac Elf (RCA1802)
  36. Cosmac Microtutor
  37. Cosmac Netronics ELF II
  38. Cosmac VIP
  39. Cromemco System I
  40. Cromemco System III
  41. Cromemco Z-2D
  42. Datapoint 2200
  43. Digi-Comp I (flat box)
  44. Digi-Comp I (square box)
  45. Digital Computer Lab
  46. Donner 3500
  47. Durango F-85
  48. Dynabyte
  49. E & L Inst MMD-1
  50. E & L Inst MMD-2
  51. Eagle II
  52. Electric Tabulating Machine (one original counter, 1889)
  53. Electronic Associates TR-10
  54. Electronic Associates TR-10 Model II
  55. Electronic Associates TR-20
  56. Electronic Associates TR-48
  57. Electronic Associates Model 180
  58. Electronic Associates 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. Intertec Superbrain
  93. ITT MP-EX
  94. JR-01 Computer
  95. KIM-1
  96. LAN-DEC
  97. LAN-DEC 20
  98. LAN-ALOG
  99. Lehrcomputer (Germany)
  100. Lawrence Livermore Lab
  101. Lear Siegler ADM3A
  102. Logikit LK255 (Feedback)
  103. Logix SF-5000 Electronic Computer
  104. MAC-1 Mini Analog Computer
  105. MAC Tutor (Bell Laboratories)
  106. MEK6800D2
  107. Micro 68
  108. Microtan 65
  109. Midwest Scientific Instruments 6800
  110. Minivac 601
  111. Minivac 6010
  112. Mini-Scamp Microcomputer
  113. Nascom I
  114. Nascom II
  115. National Radio Institute 832
  116. NEC TK-80
  117. NorthStar Horizon
  118. Olivetti Programma 101
  119. Olivetti Programma 203
  120. Olivetti Programma 602
  121. Open University PT501
  122. Ordinateur d'Apprentissage JR-01
  123. Osborne 1
  124. OSI 300
  125. OSI 600 (SuperBoard II)
  126. OSI C2-OEM-4
  127. OSI Challenger-1P
  128. Pastoriza Personal Analogue Computer
  129. Pertec MITS 300/25 (Altair desk business system)
  130. Pertec MITS 300/55 (Altair Turnkey business system)
  131. PolyMorphic Systems 8810
  132. PolyMorphic Poly-88
  133. Protech-83
  134. Range Keeper Mk.6 Mechanical Analog Computer, 1926
  135. Range Keeper Mk.7 Mechanical Analog Computer, 1935?
  136. Sargent-Welch Scientific Company Cat. No.7528 Analog Computer
  137. Science of Cambridge MK-14 (Sinclair)
  138. SD Systems Z80 starter kit
  139. Sharp MZ-40K
  140. Sharp MZ-80k
  141. Siemens ECB-85
  142. Signetics Instructor 50
  143. Sinclair ZX-81
  144. Smoke Signal Broadcasting
  145. Sol-20
  146. Spark16
  147. Sphere 1
  148. Sphere/SWTPC Computer System
  149. SWTP CMOS Microlab
  150. SWTP CT-82 Terminal
  151. SWTPC 6800
  152. SWTPC 6800 (w/ Smoke Signal Broadcasting drive)
  153. SWTPC CT-64 Video Terminal, SS-50
  154. SWTPC TV Typewriter II CT-1024
  155. Synertek VIM-1
  156. Synertek SYM-1
  157. Systron-Donner 3500
  158. Tei MCS-112
  159. Tektronix 4006-1
  160. Telefunken RAT 700
  161. TI LCM-1001 (Microprogrammer)
  162. TI LCM-1001 (Microprogrammer)
  163. TI Silent 700 Terminal
  164. TI TM 990/189
  165. Vector 1
  166. Vector 3
  167. Vidac 336
  168. Wang 2200
  169. Welch Scientific Company Cat. No.7528 Analog Computer
  170. Xerox 820 Mark I
OTHER COMPUTERS (LUGGABLES 1982-1986)
  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
RARE & NOTABLE DOCUMENTS
  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. Calculating Machines (1947)
  6. Moore School Lectures Vol. II (1947)
  7. Mathematical Theory of Communication (1948)
  8. Communication Theory of Secrecy Systems (1949)
  9. The "Moore's Law" article (Electronics, 1965)
  10. Printout from Babbage's Difference Engine #2 (London Science Museum, 2004)