Vintage HP-28S Black Handheld Programmable Advanced Scientific Calculator

US $124.99
ApproximatelyRM 518.42
Condition:
Used
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Located in: Lemon Grove, California, United States
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eBay item number:136596920084
Last updated on Nov 15, 2025 13:11:11 MYTView all revisionsView all revisions

Item specifics

Condition
Used: An item that has been used previously. The item may have some signs of cosmetic wear, but is ...
Country of Origin
Singapore
Vintage
Yes
UPC
0088698000106
Category

About this product

Product Information

The HP-28 is a series of scientific calculators introduced by Hewlett-Packard in the late 1980s. The first model was the HP-28C. It was released in 1987 and had only two kilobytes of RAM or random access memory. A year later, HP released the HP-28S model, the second and last in this particular line. This was a more advanced scientific calculator and had a capacity of 32 kilobytes of RAM. These were among the first scientific graphing calculators, which means that they had the capacity to solve calculations graphically. The HP-28S became the more common and popular calculator of the two. It is a lightweight handheld scientific and graphing calculator that weighs in at a mere 7.2 oz. It is pocket sized and offers just the right balance between power and ease of use. It has a simpler menu structure yet still provides multiple programming options. The display is 137 x 32 pixels with a dot matrix, monochrome LCD. This allows for four lines of data to be displayed on the screen. The calculator provides direct entry for algebraic formulas and an RPN input logic for interactive calculations. The information is displayed in a dynamic way with infinite stack viewing. This calculator performs a number of specific functions. You can perform algebraic manipulation, which means symbolically solving equations for any variable. You can do calculus, calculating derivatives, and definite and indefinite integrals. You can also solve math linear equations and perform binary bit manipulations. Users can calculate single and paired-sample statistics and probabilities and plot them on a graph. Finally, you can make unit conversions using any of the 120 built-in unit combinations.The 28S uses a regular battery, so you don't have to invest in special batteries. It has a protective clamshell case that flips open and comes in a variety of colors. The left side of the cover features a QWERTY alphabetic keyboard, while the right side features a regular scientific calculator keyboard. The unit has a regular key size. The power comes from a custom chip containing an improved Saturn processor core that runs at 1MHz. This new mini processor was so special that it was given a codename of Lewis. Each style of processor had a particular name taken from the Lewis and Clark expedition. Each provided something innovative, and this one provides the user with a file directory system. This is used for filing variables and storing functions and programs to use later. The HP-28S calculator offered a series of firsts. It was the first to offer RPL, or Reverse Polish LISP, as its programming language and was the first scientific calculator capable of symbolic computation. Even with all the capability, the 28S is simple to operate. There are four editions of manuals that you can use as guides. With these innovations, the HP-28S is a reliable device for solving advanced equations.

Product Identifiers

Brand
HP
UPC
0088698000106
Model
28S
eBay Product ID (ePID)
166527924

Additional Product Features

Power Source
Battery
Size
Pocket
Key Size
Regular
Type
Scientific

Item description from the seller

About this seller

sd1904rene

98.1% positive feedback16K items sold

Joined Apr 2010

Detailed Seller Ratings

Average for the last 12 months
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4.8
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5.0
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  • p***4 (459)- Feedback left by buyer.
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    The Blu-Ray arrived very quickly and was in very good condition, just as described. Inside the package, the Blu-Ray was wrapped in bubble wrap for extra protection. Thank you very much for a pleasant and easy transaction.
  • 8***1 (3)- Feedback left by buyer.
    Past 6 months
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    Great seller and fast shipping! (package was delivered in 3 days). The bucket is in brand new condition and the quality is great. I found this to be the most affordable option too. The bucket looks amazing and it also comes with its superman/krypto print.
  • r***r (388)- Feedback left by buyer.
    Past 6 months
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    Unfortunately I only receive three I clearly ordered four you only sent me three I paid for four you sent me three I have four kids not three so I need four tapes not three not cool the tapes look like they seen better days clearly you were advertising selling 4 but you only sent me three so either send me one more or give me a refundunfortunately I cannot leave you a bad review at this but if do not fix I will leave a bad review THAT IS A PROMISE