Specifications for Wang 720C

Manufacturer: Wang Laboratories, Inc.
Model Number: 720C
Serial Number: Three Units in Museum
#1: 875842C (Upgraded from 720B)
#2: 875055-0 (Non-Operational, ROM Problem)
#3: 675842C (Upgraded from 700B)
Date of Manufacture: #1: Mid-1972
#2: September, 1971
#3: June, 1971
Manufactured In: USA, Tewksbury, Massachusetts
Original Price: Base Price $7,000 [From Oct. '71 Price List]
Weight: 39 Pounds
Size: 20" Wide, 20 1/2" Deep, 9" High
Power Requirement: 90 Watts, 115VAC, 60Hz
Display Technology: Nixie Tube, 32 tubes arranged in two rows of 16
Logic Technology: DTL & TTL Small and Medium-Scale Integrated Circuits
16K-bits of Magnetic Core Memory
Ferrite Transformer-Based Microcode ROM
Digits of Capacity: 12 significant digits plus sign
2 digits plus sign for exponent
Left-Justified, Left Entry, No trailing zero suppression
Decimal Modes: Full floating or modified scientific notation
Arithmetic Logic: Arithmetic for Addition & Subtraction
(Up-Arrow) key for entering 1st operand of multiply/divide
Math Functions: Four Function,
Integerize, Absolute Value, Pi Recall,
Square Root, Square, Reciprocal,
ex, 10x, Base e and Base 10 Logarithms
Constant: Automatic on all four functions
Memories: 248 Registers [As Equipped]
Direct and Indirect Memory Access
Four function math available on all memory registers
Programmable: Yes, Learn Mode w/conditionals, labeled branches, subroutines
1,984 Steps of Program Storage
Peripherals: Built-in Cassette Tape Drive for Program/Data Storage
Extensive Add-On Peripheral Options: (Prices from Oct., '71 Price List)
- Model 701 Output Writer [2 Pages] [PDF] ($1,800)
- Model 702 Plotting Output Writer [97K] ($3,500)
- Model 702P Portable Plotting Output Writer [61K]
- Model 703 Paper Tape Editor [PDF] ($1,350)
- Model 704 Punched Card Reader [PDF] ($600)
- Model 705 Micro Interface [PDF] ($300)
- Model 706/707 Teletype Terminal Interface [PDF] ($2,800)
- Model 708-1 Expansion Memory Controller ($1,500)
- Model 708-2 4K External Memory Expansion Module ($1,500)
- Model 709 Dual Cassette Tape Drive ($2,500)
- Model 710-1 Fixed/Removable Disc Drive [2 Pages] [PDF] ($6,000)
- Model 711 I/O Typewriter (Modified IBM Selectric I/O) [PDF] ($2,500)
- Model 712 Analog Flat-Bed Plotter [PDF] ($2,500)
- Model 714 Mark Sense Card Reader ($450)
- Model 718 Extended Program Memory
- Model 721 High Speed Line Printer [19K]
- Model 722 Alphanumeric Input Keyboard
- Model 723 I/O Buffer
- Model 727 Communications Interface
- Model 729 Dual Cassette Drive
- Model 730 Fixed/Removable Hard Disk Subsystem
- Model 732 Digital Flat Bed Plotter
- Model 733 Paper Tape Reader
- Model 740 Dual Flexible (8") Disk Drives
- Model 741 Thermal Printer
Performance: Add/Subtract: 1.7ms
Multiply, Square: 12.0ms
Divide, 1/x: 17.6ms
Square Root: 99.0ms
ex: 61.8ms
Loge(x): 47.2ms
Core Memory Cycle Time: 5.0us
Other Features: Large library of software applications
Notes: These calculators were marketed heavily to auto dealerships for use in prparing consumer loan paperwork. Custom programs were written for use with the Model 701 Output Writer. The loan officer would enter the principal, down payment/trade-in, interest rate, and term into the calculator, and a loan application form would be fed into the Output Writer (a Wang-modified IBM Selectric). The calculator then would figure the amortization and payment information which would be formatted and printed on the Output Writer.


The Soviet Union produced a 'clone' of the Wang 700-series calculator, known as the Elektronika D3-28. This machine used similar small-scale IC technology and a Soviet-made copy of Wang's ferrite transformer ROM.

Tech Notes: Wang IC Reference
Tech Notes: Wang 700 Architecture
Tech Notes: Wang 700 Circuit Board Inventory

Previous Machine: Casio FX-1
Next Machine: Compucorp 110/X

Related Machines: Wang 144T
Wang 600
Wang C-52
Wang 360E
Wang 360SE
Wang LOCI-2

Advertising: Eary Wang 700-Series Product Brochure, March 1969 [5 Pages] [57K]
Wang 700-Series Product Brochure, October 1970 [6 Pages] [103K]
"WANG 700 Calculator or Computer?" [91K]
"Tested by skeptics." [43K]
"A new school of thought." [79K]
Preliminary Data Sheet - WANG'S NEW 700C/720C Series [269K]
Wang 700-Series Data Sheet [141K]
Wang 700 Advanced Programmable Calculator Data Sheet [92K]
Wang 700 Series Commercial Price List [Oct., 1971] [75K]
Literature: Cover of Wang 700 Interim Instruction Manual [50K]
Cover of Wang 700C/720C Reference Manual [59K]
Cover of Wang 720A/B Reference Manual [59K]
Cover of Wang 711 I/O Writer Reference Manual [62K]
Wang 700 Series Program Codes [114K]
Reading: "Lessons, an Autobiography"
Author: Dr. An Wang with Eugene Linden
Publisher: Addison-Wesley
First Printing: August, 1986
ISBN: 0-201-09400-2

"Riding the Runaway Horse: The Rise and Decline of Wang Laboratories"
Author: Charles C. Kenney
Publisher: Little, Brown and Company
First Printing: 1992
ISBN: 0-316-48919-0

Patents: US Patent Number 3,760,171 [700-Series Calculator]
US Patent Number 3,727,201 [ROM]

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