Credit Card-Sized 8-Bit Computer Teaches Machine Language
Write programs using switches and lights, just like the first generation of home computers.
To understand how a processor works, you have to get down to the assembly or machine language level. But, today's programming languages, purposely, have many layers between the user and the hardware's bare metal. While writing assembly is possible on a modern PC, it isn't very fun (or interactive.) SubsySTEMs has an excellent approach to teach how processors work. They created an 8-bit microprocessor trainer that is only 2.25 x 4 inches, or 57 x 102 mm. With this board, you can write simple programs using assembly or machine language without the need of a PC.
Here is what SubsySTEMs said about creating the 8-bit microprocessor trainer:
I love vintage computing and think that using these devices helps really understand how today's computers work on the most fundamental level. You are the "compiler" and have to make the decisions of where to put data and when to get it. This allows you to much better understand variables, memory locations, pointers, and references.
Like very early home computers, the 8-bit microprocessor trainer uses switches and lights for its input and output. (The micro USB connection is for power only.) Instead of switches, like those found on an Altair 8800, the computer trainer uses push buttons. One set for data input and another set for commands. LEDs provide the output of the registers and memory.
There are 62 op-codes in the simulated processor's instruction set. Typical instructions like moving data between registers are available, along with a couple of non-typical instructions. For example, there is a BRT op-code to set LED brightness and TEMP op-code to read the 8-bit microprocessor trainer's onboard temperature sensor.
To see example programs check out the detailed instructions manual, which includes several. One such example is called "Robot Eye," which might be better known as a "Larson Scanner." It is a pattern where LEDs turn on from left to right. Other examples include a timer, a multiplier, and random flashing lights.
To download the manual or to order one, check out the Tindie store page for the 8-bit microprocessor trainer. Each trainer comes fully assembled for $25 (plus shipping.) While there, you might also want to check out SubsySTEMs 4-bit trainer as well.