A good mind-breaker useful for solving a real tasks. For example, tasks that programmers solved when sending man to the Moon. Along the way, you’ll acquire Assembly programming skills and refresh your math knowledge.
All Reviews:
Mostly Positive (14) - 78% of the 14 user reviews for this software are positive.
Release Date:
Apr 21, 2020

Sign in to add this item to your wishlist, follow it, or mark it as ignored

Early Access Software

Get involved with this software as it develops.

Note: This Early Access software is not complete and may or may not change further. If you are not excited to use this software in its current state, then you should wait to see if it progresses further in development. Learn more

What the developers have to say:

Why Early Access?

“Full-function Assembly binary computer in the ‘sandbox’ mode. The idea of our App suggests the existence of a training mode. While it is still under development, we decided to give users familiar with the programming basics the opportunity to play with the Computer in the ‘sandbox’ mode using manual.

Since this is the first binary computer of its kind, we would like to receive feedback from users with suggestions for future development.”

Approximately how long will this software be in Early Access?

“The release of the App is scheduled for the second half of the 2020.”

How is the full version planned to differ from the Early Access version?

“In the full release it is planned to add a training mode, the option for sharing the programs, and more.”

What is the current state of the Early Access version?

  • The App works in the ‘sandbox’ mode.
  • The Computer contains full list of Assembly instructions.
  • There is a step-by-step debugging mode.
  • Feature of saving & loading programs
  • There is the User Manual and the Instruction Set Guide (in the App Help, the documentation on the website, files to download).

Will this software be priced differently during and after Early Access?

“Yes, the App with additional functionality will cost more.”

How are you planning on involving the Community in your development process?

“It is important for us to get feedback from users on the Computer to develop a training mode and to possibly add other functions. We will carefully read reviews and discussions on the Steam forums and take into account the views of community.”
Read more

Buy ASTRA-256 Assembler

See all discussions

Report bugs and leave feedback for this software on the discussion boards

About This Software


Maybe it sounds unusual but let us introduce a binary computer programmable in Assembly language.


  • The ASTRA-256 software is an effective tool for those who want to learn the Assembly language, not knowing where to start.
  • It is a fun toy for ‘real programmers’ and those remembering the old LPG-30, Altair 8800, PDP-11.
  • Finally, it’s a very good mind-breaker, not wasting your time. With the ASTRA-256, you can solve real problems. For example, those real programmers solved at the dawn of computing. Along the way, acquiring Assembly programming skills, refreshing your math knowledge.


  • Assembly language allows to most effectively manage all the hardware resources. So it is used for programming many microcontroller devices.
  • Assembly is still used to optimize programs written in higher-level languages.
  • Assembly experience will give you an insight into how the magic happens. What turns hardware understanding only zeros and ones into a living intelligent computer?


In the software, we tried to marry the atmosphere of the iconic first computers with a practical training tool. At the same time, you can prove yourself working in limited-resource conditions in which real programmers had been working in their days.


The software represents a virtual computer with a von Neumann architecture. At your disposal are the following resources:


The 8-bit processor has an 8-bit accumulator, as well as 8-bit registers mapped to memory: instruction counter, input register, output register, stack pointer, FLAGS register.


The Astra-256 has 256 bytes of memory (exactly as it was in the first versions of the Altair 8800).

Instruction Set

The Assembly instruction set is quite extended and contains 102 instructions. But a novice user does not need to know all of them. It is enough to know only part of them to start writing the first assembly code.

To learn more about instructions, click on the Help View button in the app or read detailed documentation on the official website. You might want to print it for more immersion in the programming process.

Instructions grouped into 11 subdivisions:

  • Processor Control Instructions
  • Data Transfer Instructions
  • Exchange Instructions
  • Arithmetic and logical Instructions
  • Shift Instructions
  • Bit Manipulation Instructions
  • Stack Manipulation Instructions
  • Unconditional Transfer Instructions
  • Conditional Transfer Instructions
  • Input/Output Instructions
  • Miscellaneous Instructions

We provide the user with an extended set of instructions similar to those found in all modern microcontrollers, microprocessors. The ASTRA-256 allows for getting basic programming skills in low-level hardware. On these foundations, you can master the coding of any modern microcontroller. After all, its basic operating principles remain the same.


The ASTRA-256 is a tool with everything at hand. It allows puzzling over the solution of tasks with limited resources.

Write in Assembly language a square root extraction program, a trigonometric function calculator, or an interactive game. And maybe you will be the next real programmer who sends a man to the Moon.

System Requirements

SteamOS + Linux
    • OS: Windows 10, 8.1, 8, 7, Vista (32, 64 bit)
    • Processor: Dual Core 2 GHz
    • Memory: 64 MB RAM
    • Graphics: Requires a Direct3D 11 compatible videocard
    • DirectX: Version 11
    • Storage: 50 MB available space
    • OS: Ubuntu 16.04 LTS 64-Bit
    • Processor: Dual Core 2 GHz
    • Memory: 64 MB RAM
    • Graphics: Requires a OpenGL 1.4 compatible videocard
    • Storage: 50 MB available space

What Curators Say

1 Curator has reviewed this product. Click here to see them.

Customer reviews

Review Type

Purchase Type


Date Range
To view reviews within a date range, please click and drag a selection on a graph above or click on a specific bar.

Show graph

Filter reviews by the user's playtime when the review was written:

No minimum to No maximum
Display As:
Show graph
Hide graph
Excluding Off-topic Review Activity
There are no more reviews that match the filters set above
Adjust the filters above to see other reviews
Loading reviews...