scottpiersall/sicvm

A SIC Virtual Machine, Emulator Assembler, loader, and Linker

sicvm's Issues

Decimal Button

Create a new button in the memory table which displays the table in decimal.

Place it alongside the hex and binary buttons.

Can't step through .obj file

I loaded my .obj file and it won't let me step through my program. I think it went straight to the end of my program because my program counter is at 26 and there are other values in my registers. I tried to set the value of the program counter using Machine
then Set program counter to ,but it did not do anything.

Binary Button

Make the binary memory view button work

Bytes do not work

Instructions I have encountered that do not handle bytes:
WD
COMP
ADD

Basically anything a byte touches, breaks.

Only time it seems to work is for bytes in sets of 3

Run button issues (enhancement)

Disclaimer: enhancement, not bug

The run button appears to occupy the entirety of the program's processing, leading to crashes if anything loops, and long periods of time where the application window is unusable.

If multithreading is possible, maybe it would be doable to keep the window functioning properly while the code is running.

Other useful features that could go along with this would be a visual indicator showing that the code is in the process of running, and/or a stop button.

Use binary literals and consts for CPU constants

For things that are constant in the CPU, such as CC max (binary 11) we can use constant literals to make code easier to digest for new contributors.

Example:

// definition
public const byte CC_Max = 0b11 << 6;
// OR
public const byte CC_Max = 0b11000000;
//
// later in the code
//
case 0x30: //   JEQ 
    if ((SW & CC_Max) == 0)
    {
        PC = TA;
    }
    else { this.PC += 3; }
    break;

Alternatively, we can consider making them static and initializing them using their actual values, e.g.

public static byte CC_Max = 0b11;

and later either translate them as needed or simply doing the conversion during the declaration, not sure, we can get creative.

Missing start causes Assembler to output wrong object code.

Expected output similar to

HNONAME00000000002B
T0000000B5445535420535452494E47
T0000161500000000000B04001650800054800B2C001938001C
E00001C

But as we can see, output is

HSRC 00000000002B
E00001C

Reserved memory causes undefined behavior unless jumped over

If you try to use resb, resw, word, or byte anywhere that the program counter reaches, it leads to unintentional behavior and sometimes stalls the machine.

My guess as to why this happens is it tries to run the contents of the reserved memory as if they were opcodes, when it should instead get skipped over.

For now, this is avoidable by placing all reserved memory in places that are bypassed with J, JGT, JEQ, or JLT.

JEQ doesn't work properly

JEQ does not jump on CC is equal to.

SIC VM only recognizes \t between operator and operand

My lines are aligned correctly with \t, but some lines have a space and \t between instruction and operand.

JEQ uses wrong conditional for checking if it should jump

JEQ jumps when CC is 10 | 01, making the only case where it doesn't jump, when cc = 0.

Current Instruction

Currently you can only see the next instruction on the panel on the top right. It would be extremely useful to know what instruction we are currently on.