"PC-98" is a term used by the Western community to refer to the first 5 games of the Touhou Project. "PC-98" is named after the NEC PC-9801 computers on which they ran on. The Japanese community's equivalent is "old works" (旧作 kyuusaku), a term reflecting the technologically inferior FM Synthesis music & 16-bit colour graphics. ZUN has used both the Japanese and English terms interchangeably. Additionally, PC-98 games are distinguished from later "Windows games" for having been distributed by Amusement Makers instead of Team Shanghai Alice.
Factors which caused the end of the PC-98 games include a hiatus brought on by ZUN's graduation & employment at Taito, as well as the decline of PC-9801s. The PC-98 games are less well known, possibly due the aging hardware they ran on, their release during the dawn of the Touhou community & their relatively limited circulation. Highly Responsive to Prayers and Story of Eastern Wonderland were sold simultaneously at Comiket 52, with the former initially selling only 30 copies and the latter 50. 200 to 300 copies of Lotus Land Story were sold on its release, while Phantasmagoria of Dim.Dream sold fewer than 100. On 19 September 2002, ZUN ceased sales and support for PC-98 games. ZUN later released arrangements of many themes from the PC-98 games in MIDI format on his old website. ZUN has stated in Akyu's Untouched Score vol.3 that he loves FM Synthesis, but would much rather not go back to 16-bit graphics.
- 東方靈異伝 ～ Highly Responsive to Prayers (Amusement Makers/ZUN Soft 1996)
- 東方封魔録 ～ Story of Eastern Wonderland (Amusement Makers/ZUN Soft 1997)
- 東方夢時空 ～ Phantasmagoria of Dim.Dream (Amusement Makers/ZUN Soft 1997)
- 東方幻想郷 ～ Lotus Land Story (Amusement Makers/ZUN Soft 1998)
- 東方怪綺談 ～ Mystic Square (Amusement Makers/ZUN Soft 1998)
Unlike the Windows era, the PC-98 world was mostly undefined. Initially, the games were simply set in an "Eastern Country". Locations in the Eastern Country included Makai, the Human Village, the Fantasy World, Mugenkan, Reimaden as well as the recurring Hakurei Shrine. The world was inhabited by humans, youkai & demons. However, the term Gensokyo has been used since the title of Lotus Land Story. As of Mystic Square, it's been used as the name of the world the games take place in. ZUN has confirmed it to be the very same Gensokyo as in the Windows games.
As in the later works, a shrine maiden named Reimu Hakurei (博麗靈夢) lives at the shrine, with her friend Marisa Kirisame visiting occasionally. In PC-98, Reimu's turtle Genjii also lives at the shrine, along with Mima who haunts and torments visitors out of boredom. Like their successors, the PC-98 games begin with Reimu or another character going out to investigate and resolve incidents. However, there was no mention or use of the spell card rules in the PC-98 universe, as they were put into use in the gap between Mystic Square and Embodiment of Scarlet Devil.
The Windows era may be considered a soft reboot - while the series kept the name "Touhou Project", ZUN stated that it was a "clean sweep", with the current setting of the Touhou Project coming together for the first time in EoSD. Hence, no PC-98 character has reappeared in a Windows game except for Reimu Hakurei, Marisa Kirisame, Alice Margatroid and Yuuka Kazami due to the awkwardness of fitting older characters into the story. They have, however, "retired and are warmly watching over things". ZUN has mentioned in at least 2 interviews that Genjii is "probably still living in the lake behind the shrine".
Despite the above, however, the PC-98 era cannot be taken entirely at face value - the tone of the games is much more light and tongue-in-cheek, with a fair bit of references to other, non-Touhou works (particularly those of Izumi Takemoto). Additionally, ZUN has said that HRtP was simply a study project, and had once compared the games to "derivative works". In case of any plot holes, ZUN has said to take the latest material as the most accurate..
The NEC PC-9801s were a series of personal computers developed by NEC, which were equipped with 16 or 32-bit Intel x86 CPUs. While outwardly similar to IBM's PC and compatibles, including the use of DOS, it was for the most part a proprietary architecture. PC-9801s included dual µPD7220 video display processors, one each for text and graphics. In graphics mode, they could display sprites with four 16-color palettes selected from 4026 possible colors. Various expansion cards could be installed in PC-98 systems, including more capable video or audio cards, but only the base hardware is required for the Touhou games. ZUN developed the PC-98 games with the PC-9821 computer as a hardware benchmark and specified a 486 at 66MHz as the bare minimum.
As for sound hardware, the PC-9801VX and many subsequent models came default with the PC-9801-26k soundcard. This includes the Yamaha YM2203 OPN FM synthesizer, providing three 4-operator FM synthesis channels plus the three channels of the integrated YM2149 SSG unit. Users could replace this with the PC-9801-86 soundcard with the much more capable YM2608 OPNA chip, doubling the amount of FM channels and adding a few other features. As such, the PC-98 games included two versions of their in-game music, made for either the three or six FM channel hardware. All of the music was programmed in MML with M. Kajihara's Professional Music Driver (PMD), except for Highly Responsive to Prayers which used Mdrv2 for the music driver. Story of Eastern Wonderland also supports outputting to a MIDI device. Phantasmagoria of Dim. Dream was presumably also planned to have MIDI support, but it was scrapped during development.
- It has been shown in an interview that ZUN still owns a PC-98 computer, on which he played Highly Responsive to Prayers for the first time in years. He felt nostalgic.
- Since any software made for Windows 2000 or earlier can be run both on the IBM-compatible Windows 2000 and the PC-98 Windows 2000 without compatibility problems, technically all Touhou games up to at least Undefined Fantastic Object should be able to run on a PC-98 as long as the appropriate DirectX version is installed. However, since the last PC-98 system was released in 2000 (the PC-9821Ra43, which had a 433MHz Celeron, whereas the system requirements of the Embodiment of Scarlet Devil ask for a 500MHz Pentium) this is generally not viable in practice.
- ZUN intended to cease all doujin activites after the PC-98 games - his initial idea was to do so after Lotus Land Story, then after Mystic Square. Alas, he could not wash his hands clean.
- PC-98 characters are often shown in fanworks with their similar Windows counterparts (for example, Sakuya Izayoi with Yumeko).
- Because PC-98 computers are no longer sold/manufactured, fans use emulators to play these games on modern PCs, but they can also be played on homebrew Nintendo Wii systems as well. The emulators most commonly used for the PC-98 games are T98-Next, and Neko Project 21 (for the latter it's advised to use the unofficial fmgen builds that're linked from here instead).
- Many fans consider the PC-98 ecosystem to be old or obsolete, to the extent that it is generally associated with nostalgia.
- There are FM Synthesis remixes exist of later songs mimic the PC-98 style. One notable example is the album PC-98 Perfect Cherry Blossom. There's also artwork of modern Touhou characters drawn in the PC-98 style.
- The Untold History of Japanese Game Developers Interview - interview between John Szczepaniak and ZUN
- twitter message on 2010 February 11
- According to a post by ZUN on 2005 April 01.
- Mystic Square - music comments
- ZUN's AWA Q&A Panel
- Imperishable Night - Afterword
- Strange Creators of Outer World vol. 3
- Meiji University talkshow "Dawn of Touhou"
- ZUN's Gensou Denshou Lecture
- ZUN's E-mails
- The Cutting Room Floor
- Mystic Square - music comments (東方幻想的音楽 arrangements)