Comparison of Casio FX-115ES PLUS and Casio FX-300ES Plus based on specifications, reviews and ratings. Casio FX-115ES PLUS Casio FX-300ES Plus; Battery operated: yes. External power connection. Suggested Casio FX-991EX Casio FX-991ES Plus Casio FX-991ES Casio. Solar powered with battery backup. Product Details. Item # 369889: OfficeMax # 23313558: Manufacturer # FX-115ES PLUS: color: Silver power source. Casio® fx-115ES Plus Scientific Calculator. Description Product Details Customer Reviews. Product Review for Renata Battery Replacement for Casio FX-115ES Plus Calculator Long-lasting power for your coin-cell-operated devices such as household electronics like keyless entry systems, e-books, toys, calculators, watches, heart rate and glucose monitors and more. Casio fx-991EX ClassWiz Answer: 5570898.583 Time to Solve: 17.3 sec Casio fx-9750gii Answer: 5570898.583 Time to Solve: 4.9 sec As you can see, the Texas Instruments device is a slow-poke. The TI-36X Pro costs anywhere from $19 to $30 on Amazon. The Casio fx-991EX ClassWiz is the official (and substantial) Casio upgrade to the earlier Casio fx.
I decided to share this log as this trusty computer 计算机 been with me for 20 years and I just threw it away today.
I got myself a very new FX991. Well it is a 8 bit computer , with no ram no harddisk, with some register and with a display of 10+2 character.
Cross Product Casio Fx 115
What are the modification done to this machine ?
1) Overclock to 5X the speed. Tested with stopwatch, the slowest operation with this calculator is 110C52. The combinatorial function
C(n,k) is defined as n!/[k!(n-k)!], where n! is the factorial function.
Casio Fx 115s Battery Charger
Normal calculator can take up to 20s to find the answer. On my HP 11C it took over a minute.
After overclocking it took about 2s in non turbo mode and within 1sec in turbo mode.
2) added Rechargeable battery, these battery are charge using the solar panel allowing the calculator to be use without any light. I wounder why after so many years calculator still do not have this function. The rechargeable battery can last up to a week when new.
3) turbo, overvoltage overclocking. Crazy speed for bragging rights only.
Here I have a picture of the rechargeable battery switch. Have to on this to charge as well. The rechargeable battery is the one in blue above. They make the calculator FAT so that it would angle up for easy viewing , this open up the space available inside to add part required for this mod. Notice the wraping of plastic near the top, This is cause by overheating when I tried to charge the rechargeable directly under a lamp.
Here is the TURBO switch
Note the exam approval sticker at the back, The calculator with mod made it to A level, and all my U exam.
Next up is how overclocking and LCD contrast are adjusted, by changing the resistor on the RC (resistor capacitor circuit). Yes they do not have to invest in expensive crystal for clock control and it rely on an RC network, maybe they have a 555 inside. (555 is a clock control IC)
So after reading this article have you press 110C52 on your calculator to see just how long it take for it to calculate that. Got you!!!
Casio Fx 115 User Manual
Casio are one of the world's largest manufacturers of pocket calculators. The company was founded in Japan in 1946 (originally called Kashio Seisansho) and has its headquarters in Shibuya, Tokyo. As well as calculators, the company manufacturers a wide range of electronic equipment including electronic musical instruments, cameras and watches. The company was founded by engineer Tadao Kashio ('Casio' is an anglicized version of his name) who invented a cigarette pipe which became the company's first product. The compay then worked on other engineering product manufacturing until his brother Toshio suggested that they develop an electro-mechanical calculator. At the time electric calculators were essentially motorized versions of hand operated devices, but the new calculator was based instead on relay technology used in telephone exchanges. It was launched in 1954 and was the first to be manufatured in Japan. The company moved to electronic designs in 1965 with the launch of its first 'all-transistor' model, with integrated circuits taking over in the late 1960s, although electronic calculators were still large, expensive desktop devices. The first pocket calculators were the various versions of the Casio Mini, using six-digit vacuum fluorescent displays. Although they were just one of many calculator manufacturers in the 1970s, by the 1980s Casio was a technology leader launching the world's first graphing calculator, the Casio fx-7000G. Casio continue to be one of the largest calculator manufacturers, with their scientific models used widely in schools throughout the world.
More information can be found at the Casio corporate website. User Manuals can be found at the manufacturer's site