Heiankyo Alien
trivia

The hardware is the same as Head-On (Sega) (a copy), with some modifications to the sound. The CPU is a Z-80.

When they started development with the intention of finishing it during the summer vacation, they found that there were no specifications for the hardware's display system, etc., so they had to start from scratch by analyzing the hardware and creating a hardware specification document.

The program was written by TSG members, all writing assembler on paper with pencil.

A member who is good at typing will input the completed programs on papers. He typed them into the only development machine and
assembled it into machine codes.

The completed program is stored in seven 2KB
UV-erasable programmable ROMs.
Burn them, plug them into the actual machine, and try it out then rewrite the program in pencil, over and over.
It was the method of the program development at that time, no simulator no debagger no ICE.

The development was supposed to be completed during the summer vacation, but it never ended.
They were getting nervous as the final exams were approaching after the summer vacation.
In the end, all they were able to do during the summer vacation was analyze hardware specifications and build the framework of the program.
The development of the program was restarted and completed during the fall break after the final exams.

The arcade version of the program uses a rarely used Z-80 instruction called JPE (Jump Parity Even) to improve efficiency.

In early versions, if you put in too many coins, the program stack would break the walls around the city on the screen, allowing the aliens to escape into memory space outside of the screen.

Mysteries of Aliens
- Where do they come from?
- What do they do?
- What do they do when they capture humans?
- What happens when they are buried?

At the Amusement Machine Show in Harumi, Tokyo in October 19, 1979, where the arcade version was first unveiled, someone was playing Heiankyo Alien on a table-type demo machine. In his excitement, he stood up while still gripping the control lever, nearly lifting the entire arcade machine with it!
Seeing this, the person in charge was convinced that the game would be a great success.

Outside of the show place, flyers were being handed out that read, " We are against copyright of game programs! Let us copy them freely!"

Denki Onkyo (1948-1989), which commercialized the arcade version, was a company that manufactured audio components and arcade games, and was headquartered in Ota-ku, Tokyo. In September 1982, Murata Manufacturing acquired 55% of Denki Onkyo's shares and brought it under its umbrella. In April 1989, it was absorbed into Murata Manufacturing and ceased to exist.

電気音響

Theoretical Science Group is a student club at the University of Tokyo. Founded in 1959 by Toshiyasu Kunii, the group conducted research in theoretical sciences such as physics, chemistry, and mathematics (as well as mountain climbing and skiing).
In 1976, under the suggestion and leadership of Hiromichi Hashizume, the microcomputer "KUMICOM " (CPU=8080A, RAM=4kB, no ROM, I/O=Kurotsuko Teletype with paper tape reader/writer) was built, and from then on TSG became a circle with computer theme.
In 1979, the members developed Heiankyo Alien.

理論科学グループ