Starting the simulator

SicTools simulator can be started either by simply launching sictools.jar or via the command line:

java -jar sictools.jar

If launching via command line, you can also supply the path to the asm / obj file you would like to load:

java -jar sictools.jar examples/zogice.asm

java -jar sictools.jar examples/zogice.obj

Basic features

The main simulator view is pretty easy to understand:

• CPU: displays the values of registers, information about current instruction and controls for running step-by-step or starting / stopping the cpu. You can also hover the register values to see the data in different representations.
• Disassembly: displays the disassembly of instructions and current position of PC. You can also toggle breakpoints.
• Watch: displays symbols from the assembly file and their current value. You can also toggle data breakpoints on their location.
• Memory: shows the bytes in memory, where each byte is represented in hexadecimal.

Input / Output

SIC/XE supports up to 256 devices, which can be accessed via RD, WD and TD instructions.

In order to access devices 0 - 2, you need to start SIC/XE via command line. Devices are mapped in the following way:

• 0 is mapped to standard input
• 1 is mapped to standard output
• 2 is mapped to standard error
• 3 - 255 are mapped to the corresponding <num>.dev files, where <num> represents the device number in hexadecimal format (writing to device AA writes to the file AA.dev).

More examples are available at SicDemos/stdinout.

Textual screen

SIC/XE supports a textual screen that can display ASCII characters.

It can be configured in SicTools -> Settings -> Textual screen, but default configuration is the following:

• Starting address is located at 0xB800
• Size is 80 rows * 25 columns
• Font size is 12 pixels
• Address of each pixel can be calculated by address = screen_origin + y * cols + x
• Each cell is represented by a single byte which contains an ASCII value.

Example

If we wanted to display the letters ABC horizontally and vertically (using the default configuration), we would need to write:

Address	Value	Letter
0xB800	0x41	A
0xB801	0x42	B
0xB802	0x43	C
…	…	…
0xB19	0x42	B
…	…	…
0xB32	0x43	C

More examples are available at SicDemos/text-screen.

Color graphical screen

SIC/XE also supports a graphical screen that can display pixel in different colors.

It can be configured in SicTools -> Settings -> Graphical screen, but default configuration is the following:

• Starting address is located at 0xA000
• Size is 64 * 64
• Address of each pixel can be calculated by address = screen_origin + y * cols + x
• Each pixel is represented by a single byte in the IRGB format (iirrggbb):
  • ii represents intensity - 0, 1, 2, 3 = 20, 40, 60, 80
  • color: (R, G, B) * amp

Table of all available colors (values 0-255 of a byte):

More examples are available at SicDemos/graph-screen.

Keyboard input

The Keyboard can be opened by navigating to View > Keyboard.

Whenever a key is pressed (note that the Keyboard has to be focused), the key’s character value is stored to a predefined location in the memory (default 0xC000). In a SIC program that is utilising the Keyboard, the program should clear the memory location where character values are stored after they are read.