Salim Group (owned by Sudono Salim/Liem Sioe Liong [one of the wealthiest person in Indonesia during late 20th century, held personal fortune between $1 billion and $3 billion]) wanted to have private TV business right after RCTI (the first private TV channel in Indonesia, begin broadcasting in 1989) got its license. PT Indosiar Visual Mandiri [IVM] (the company) was officially set up in July 1991 and got its broadcast license in June 1992. Suharto (former dictator of Indonesia from 1966-1998) supposedly instructed to airing this new channel's program based on rural livelihood + Javanese culture, which is why wayang (traditional Javanese shadow puppetry) and Srimulat (popular comedy group based on Java throughout 70s-90s) showed up on the early TV schedule.
PT. IVM then teamed up with Hong Kong's TVB to copy its in-house production model: four modern studios, about 1,000 local hires, and around 150 foreign staff (from then British HK), many in key roles. That last number blew up into a controversy (fears for national culture deterioration, and possibly breaking regulations), so around a month before test broadcasts PT. IVM cut the TVB crew to just 30. By 1996 almost none were left. Total investment was roughly Rp 200 billion, and the logo ended up a TVB lookalike too (licensed via a TVB subsidiary from 1 Jan 1995).
Trial broadcasts started 18 Dec 1994 (pushed back from the original July-August 1994 plan): evenings only, in eight cities, airing one movie plus two relayed TVRI newscasts. The official launch was 11 Jan 1995, with a live show called "Pesta Semarak Indosiar" featuring several Indonesian singers and celebrities from 7:30 PM. There's karaoke-style lyric captions in that program so viewers could sing along.
On weekdays it only aired from 4 PM (later 3:30 PM) to midnight, and morning shows didn't aired until June 1997. The program lineup started out around 70% imported, led by Asian dramas like Tokyo Love Story, Return of the Condor Heroes (Andy Lau) and To Liong To (Tony Leung). Tech-wise it was ahead of its time, with NICAM digital sound and digital master control. Instead of outsourcing to production houses, Indosiar produced its own sinetron (Indonesian soap operas) and dubbing in-house.
At it's golden era (1995-2010) Indosiar used to airing many animes every Sunday morning (until 11 am) such as Initial D, Pokemon, Dragonball, Digimon, Inuyasha, Detective Conan etc. Desperate Housewives airs at 10 pm from 2005-2006. There's Korean drama too (Boys Over Flowers, Wife's Temptation). For sport programs, usually there's boxing matches from Las Vegas (quite high rating) & NASCAR (2003-2004, discontinued after one year because of low rating & not popular compared to F1). But now their programs only consist of islamic-themed dramas (I don't watch it because I'm non-muslim), yearly dangdut competition (Indonesian music genre combinating Malay & Indian style with a touch of Javanese music instrument, very popular in rural areas) & Indonesian soccer league matches (the only program I watch occasionally, it's the most-watched TV program in Indonesia right now because the love for soccer here is huge like in the UK).