I was investigating a while ago to use an RPi for real-time use, and even in the "Bare metal" mode there were events that you could not control, such as the thermal calibration of the DRAM.
Also, the parallelization and synchronization of tasks is very difficult to achieve with precision of milliseconds and without additional delays. In a FPGA is something that comes "for free".
Sorry if this is old news, but I missed this update in this discussion:
#346 次世代MSXのCPUは64bit
2020-02-04
次世代MSXを東大で作っている。CPUはZ80、R800、64bitのARMにした。当初32bitのARMであったが、ソフトウェアを担当する人たちから64bitにした方がよいというリクエストがあったので変更した。64bitのARMで動くOSはLinuxである。CとPythonとLISPが使える様になる。詳しくは夏頃。
Google translate:
#346 CPU of next generation MSX is 64bit
2020-02-04
We are making the next generation MSX at the University of Tokyo. The CPU is Z80, R800, 64bit ARM. Originally it was 32bit ARM, but I changed it because there was a request from people in charge of software to make it 64bit. The OS that runs on 64-bit ARM is Linux. You can use C, Python and LISP. Details are around summer.
2020-02-04
We are making the next generation MSX at the University of Tokyo. The CPU is Z80, R800, 64bit ARM. Originally it was 32bit ARM, but I changed it because there was a request from people in charge of software to make it 64bit. The OS that runs on 64-bit ARM is Linux. You can use C, Python and LISP. Details are around summer.
Is there any progress with this project?
#444 次世代MSXの可能性を考える
2020-11-24
次世代MSXのスペックを考えている。スペックを考えるのと同時に誰がユーザーになるのかも考えている。
世の中には７つのジャイアントがいる。パソコン界ではWindowsとMac。スーパーゲーム界ではXBoxとPlayStationとNintendo。スマホではAndroidとiPhone。後発のなにかが出てこの７つと戦って勝つということができるのであろうか。答えはできないというところか。王者がひとつしかいない分野はコンピューターマニアの分野だ。そこに今大成功しているのはRasberryPiである。この分野でRasberryPiと共存しながら存在を主張し、固めていくしかMSXの未来はないような気がする。ユーザーに指示されていない30年前の8bitパソコンを2020年の現在に復活させ売っていくなんて狂気の沙汰だ。
ということを考えながら現代の７大コンピューターの隙間を毎日考えている。
Google translate:
# 444 Thinking about the possibilities of next-generation MSX
2020-11-24
I am thinking about the specifications of the next-generation MSX. At the same time as thinking about the specifications, we are also thinking about who will be the user.
There are seven giants in the world. Windows and Mac in the personal computer world. In the super game world, XBox, PlayStation and Nintendo. Android and iPhone on smartphones. Is it possible that something late will come out and fight against these seven to win? I can't answer. The field with only one champion is the field of computer enthusiasts. The Raspberry Pi is now very successful there. I feel that the future of MSX is the only way to insist on its existence while coexisting with the Raspberry Pi in this field and solidify it. It is crazy to revive and sell an 8-bit personal computer 30 years ago that was not instructed by the user as of 2020.
While thinking about that, I am thinking about the gaps between the seven modern computers every day.
Will Nishi be able to persuade us with this new MSX? I hope so, being an official product probably MSX enthusiasts will buy it but I don't know what to expect... 
I believe the magic about a MSX computer was that it could be used creatively by all kinds of users: programmers, gamers, students, enthusiasts. A new MSX needs to honor that: be simple and fun. Think about it: we are still using and creating things on machines with NO bios/software updates for decades. Of course, there are improvements, new tools, etc, but you can just turn on a MSX and start programming or playing right away. A new MSX needs to be a well done piece of hardware and software, it doesn't matter if it is 8bit or 128bit, it needs to be ready to use, ready to create, where the limitations are part of the fun. ✌
458 次世代MSXのコンセプト
2020-12-15
次世代MSXに向けてコンセプトのまとめを進めている。一番の特徴はメディアマシンであるということ。二番目はIoTのコントローラーとしての機能を持つということ。三番目はマルチCPU時代に対応するパーソナルスーパーコンピュータに拡張することができること。以上の３点であります。
Google translate:
458 Next Generation MSX Concept
2020-12-15
We are working on a summary of the concept for the next generation MSX. The best feature is that it is a media machine. The second is that it has a function as an IoT controller. Third, it can be extended to personal supercomputers that support the multi-CPU era. These are the above three points.
do you think that we can hope for this MSX machine imagined by Mr. Nishi in 2022? Rather a real machine (like MSXVR but more official) or a simple card for PC? Very exciting this project of Mr. Nishi. It would also be necessary to officially group together CDs or other old games or software and new ones. The only pity point is that it will not be by a Japanese brand.
#561 来年の計画2021-11-17
年の瀬が近くなってきて、来年取り組むプロジェクトの見直しをしている。私が来年本気で取り組むプロジェクトは次の通りである。
１、インターネット高校の展開
２、日本先端工科大学の設立準備
３、MSX次世代のハード開発とソフト開発
４、次世代（DRONE PORT付）物流センターの設計（顧客あり）
５、忍者屋敷、忍者ホテル設計（顧客あり）
このいずれもが、かなりの確度で実現するプロジェクトなのでとても楽しみである。
Google translate:
# 561 Next year's plan 2021-11-17
As the New Year holidays approach, we are reviewing the projects we will work on next year. The projects I will be seriously working on next year are:
1. Development of Internet high school
2. Preparation for establishment of Japan Advanced Polytechnic Institute
3. MSX Next-generation hardware development and software development
4. Next-generation (with DRONE PORT) distribution center design (with customers)
5. Ninja mansion, ninja hotel design (with customers)
I'm really looking forward to all of these projects as they will be realized with considerable accuracy.
#580 MSX3はどこに向かうか2022-01-19
次世代MSXの開発をやっている。FPGAを使ったRaspberryPiと同じ大きさの基盤を中心とした40年前と互換性を持たせたコンピューターシステムの設計をしている。今年中に発表して、amazonで世界中に基盤とキーボード内蔵型とMSXカートリッジ型の３種類を売る予定だ。どういう風に受け入れてもらえるかは未知数だが、Twitterでつぶやくとかなりの反響がある。
WinやMacのパソコンと競争はしないし、できない。iOSやAndroidとは全く別の世界のものである。XBoxやPlayStationやSwitchのような上級なゲーム機でもない。結局教育用の自作パソコンの分野をターゲットにして、RaspberryPiやJetsonなどと共存するニッチを目指していくことになるだろう。Twitterで世界中の人と意見交換をしているが、MSXによってコンピューターの世界に入ったというたくさんの人から感謝された。MSXが失敗ではなかったと感じてとてもうれしかった。日本のマスコミからはMSXはファミコンに押されて失敗したと烙印を何度も押されたことは悲しい思い出である。
Google translate:
Where is the 580 MSX3 going? 2022-01-19
We are developing the next generation MSX. We are designing a computer system that is compatible with 40 years ago, centered on a base of the same size as the Raspberry Pi using FPGA. Announced later this year, Amazon plans to sell three types of boards, built-in keyboards, and MSX cartridges around the world. It's unclear how it will be accepted, but tweeting on Twitter has received a lot of feedback.
It doesn't compete with Win or Mac computers, and it can't. It's a completely different world from iOS and Android. It's not an advanced game console like the XBox, PlayStation, or Switch. In the end, we will target the field of home-built computers for education and aim for a niche that coexists with Raspberry Pi and Jetson. I'm exchanging ideas with people all over the world on Twitter, and I'm grateful to many who have entered the computer world with MSX. I was very happy to feel that MSX was not a failure. It is a sad memory that the Japanese media repeatedly branded MSX as having failed because it was pushed by the NES.
