Hello its me from 2024. I made this back in 2017 and looking back I came across as abit annoying, so I apologize lol


Smallest Computer Ever.

[if enough small computers are made, this thread and the "Smallest Computer Ever" save will be turned into a list of smallest computers]

So, yeah. Thats the second smallest one 65*98.

(8 Bit Computer (max number is 2^8 = 256))

ARCHITECTURE:

8-bit ALU

4 registers

1 "standby register"

30 word RAM (you can write 8 bit values, but read 29 bit values)

31 instruction memory

15 instructions

CPU Speed is dictated by instruction speed, not by a clock.

Varies between 0.2 - 3hz

More information about its size

Size:65*98
Volume: 6370
Particles: approx. 3800

Particle value is approximate, because it creates and deletes particles as it works.

Volume to screen volume ratio:
6370:227104
                    0.0281

Particles to screen max particles ratio:
3800:227104
                    0.0167

Density to volume ratio:

3800:6370

                    0.5965

Pretty dense, considering its kinda hard to fill half of the space a computer actually occupies. Think of your own real PC right now :)

Also:

If you are willing to stack as much of these in one conventional TPT screen, you will be able to get 30 of them without the I/O ports.

What component does what:

Different components are colored and labeled.

Make your own program:

You can see more information about how exactly to program the computer.

All syntax is there. It has a built programmer in the save.

Devices:

Currently there is just 1 keypad, i should probably make it smaller. If you make any device, i can add it.

Computer has an I/O port.

Input - Input a number to the standby register. Associated with: Instruction 3 - IN, Input on IO Port, Direct input (8-bit).

Output - Output a number from the standby register. Associated with: Instruction 14 - DISP.

Standby Register

The computer has a so called "Standby Register". It is used in some instructions.

Its basically a normal register just like the other 4. Its used like a "mediator" between different operations. So if you want to load number 215 and save it to register 2, you should do that:

IN 215

SREG 2

Implementing that register was to make the computer smaller. At least with my deisgn.

Below, * means the instruction is using the "Standby Register".

Instructions (15):

1 ROL                -     Rotate Left (Actually shift) <register A>, then save in REG <register C>

2 ROR                -     Rotate Right (Actually shift) <register A>, then save in REG <register C>

3 IN                  -*   Input a number to the "Standby Register". Leave without operand to request input (outputs code 0x008000000) & waits for direct input on IO port, value goes into the "Standby Register".

4 JUMP               -     Jump to a line in the instruction ROM

5 JUMPIF A>B      -     Jump to a line, IF <register A> (>) <register B>, else increment instruction as usual

6 JUMPIF A<B      -     Jump to a line, IF <register A> (<) <register B>, else increment instruction as usual

7 JUMPIF A=B      -     Jump to a line, IF <register A> (=) <register B>, else increment instruction as usual

8 SUB                 -     Subtract <register A> & <register B>, then save to <register C>

9 SUM                -     Add        <register A> & <register B>, then save to <register C>

10 LREG              -*   Load <register A> to "Standby Register"

11 SREG              -*  Save the contents of the "Standby Register" to <register A>

12 LRAM              -*  Load RAM to "Standby Register". Address is <operand A>. ***

13 SRAM              -* Save the contents of the "Standby Register" to RAM. Address is <operand A>.

14 DISP               -* DISP is basically sending whats in the "Standby Register" to the OUT port.

15 HALT              -   Empty instruction. Stops the computer. Continues if an input is made, or the start button is pressed again.

You may wonder what are those <register A> etc. Well, if you go to the programmator, you will actually see that in each instruction you can assign up to 3 operands (numbers, that may refer to a register or something else, like a RAM address etc. Whether it says <register A> or <operand A> its all the same, but named differently so you know when it uses registers and when that number goes somewhere else, its just a value the current instruction uses to feed to different components so it does different things.)

A, referring to <register A>; <operand A>

B, referring to <register B>; <operand B>

C, referring to <register C>; <operand C>

JMP, used in instructions 4,5,6,7. Goes into the instruction ROM addresser.

Also:

More information about instruction 12: LRAM and instruction 13: SRAM.

Address number is not like a conventional number. They are in powers of 2.

So address 7 for example should be written as 128. Address 8 is 256. Etc.

This was done in order to make the computer smaller. Otherwise it would have needed some kind of decoder for the RAM.

Sample Programs:

Default: Fibonacci Sequence:

IN 1

SREG 1

SREG 2

SUM 1 2 1

SUM 1 2 2

LREG 1

DISP

LREG 2

DISP

JUMP 4

This program does not print each number on new line. It can be done, but the code for new line, space are pre-coded in the RAM. Thats because the computer allows only 8-bit numbers to pass through the BUS and therefore the RAM. However, the display's fault is that it uses all 29-bits for displaying. So i pre-loaded them in the RAM, as when loading, the information is preserved and succesfully delivered through the BUS and the OUT port.

)

JosephAustin:

How about word's smallest 16-bit computer? Also, how about (optional) ram/rom extensions?

Making it 16 bit would screw up the whole design. So, maybe I should start making even smaller, but 16bit computer now, yeah.

Extensions would be really hard to implement, but not impossible without breaking the current desing, so i will try to do it, thanks )