Otaku Programming Association (OPA)

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Site URL



Chris Rojewski

Founding Date

December 6, 1999

Years Active

1999 to 2001

Programmed For

TI-83+, TI-86, TI-89+


TI-Basic, Assembly




Radical Software
Abacus Software, Inc.
Calc Central

Otaku Programming Association (OPA) was a programming group for the TI-83+ graphing calculator. They released a few notable programs including a modified version of Falldown called Fallup and Latin Translator II for the 89; both programs were featured on ticalc.org. Hieu-Trung Le also wrote a TI-Basic programming tutorial for the TI-83 and TI-83+.

The word "otaku" means fan in Japanese, and is commonly used to refer to anime and manga.

Group Significance

  • Notable programs/games (including screenshots)
  • Notable tutorials/documents
  • Other

Group Staff

Some of the staff were involved with other TI sites and programming groups including Chris Rojewski, Doug Williams, Thomas Online (Calc Central) and Brandon Engelberth (TCPA).

  • Chris Rojewski — founder
  • Joshua Vanderburg — admin
  • Doug Williams — admin
  • Thomas Online
  • Hieu-Trung Le
  • Diego Bustamante (omotai)
  • Brandon Engelberth
  • Hex 17b
  • Samuel Squtza (Squtza)
  • Paras Baxi
  • Novasoft

Group Milestones

Site URLs

  • http://opa.ticalc.org
  • http://opaweb.cjb.net
  • http://lightning.prohosting.com/~opaweb1/

http://crr000.cjb.net — Chris Rojewski / Crr000 Programming

Crr000 Programming precursor to OPA?

Site Screenshots

Group History

(Taken from Radical Software about page)

InterCalc.org was the by-product of the Otaku Programming Association, founded by InterCalc.org's Vice-President Chris Rojewski (gro.tfoslacidar|sirhc#gro.tfoslacidar|sirhc), which was renamed from Abacus Software, Inc. (ASI), founded Christmas 98, later called AbacusĀ². It was renamed to OPA on December 6, 1999. Joshua Vanderburg joined later became the president around Febuary 2000. With Chris leaving OPA, this led to a few more members leaving and OPA wasn't making many programs. In March of 2000, Joshua decided for a change. He bought a domain name, purchase some server space, and set up InterCalc.org with the help of Brandon W. Chris was to re-unite with Joshua in June of 2000, Joining InterCalc.org. Many members tried many times, but InterCalc.org would never be announced on "the ticalc.org project" (ticalc.org), and even with the announcing on Dimension TI, InterCalc.org never received more than an average of 25 impressions a day. In September 2000, InterCalc.org received an makeover, with a new site design, server, and the first useful message board for the entire TI community. TI-Galaxy (ti-galaxy.org) had one, but it wasn't of a high enough quality to be used by all. In October 2000, Joshua planned the redesign of InterCalc.org with the help of Brandon W. On a spur-the-moment occasion, Joshua asked Michael Vincent to combine his site of Radical Software, he agreed and Radical Software exists as you know it today.

(Taken from SiCoDe homepage)

March 2000 - We have a short "war" with Novasoft, who at the end of it all go and join the OPA.

February 2000 - OPA accuse us of hacking into their site - fortunately it turns out to be someone else :)


OPA was one of the sites that got hosting through ticalc.org.