But in addition it provides a simple command line interface to display or change memory contents or set, display or clear breakpoints. From within FLEX the monitor program can be entered by entering MON on the FLEX prompt. From the monitor program FLEX can be reentered with G CD03.
This documentation describes the monitor programs U5.4 as deployed with flexemu as file monu54-6.s19. It is designed to support Eurocom II/V7 with a memory extension board. It has a FLEX boot loader and automatically boots FLEX if a disk is inserted in drive #0. It needs and only works with a RAM extension. The command input is case insensitive, and automatically converted to uppercase characters.
This monitor program overview shows which monitor program is best suited for which hardware configuration.
The following table gives an overview of the available commands:
Command | Description |
---|---|
A | Display and optionally modify CPU registers. Can be aborted by entering ESC. Register modification is only supported after a breakpoint has been hit. See also command B, C, K or S. |
B XXXX | Set breakpoint at address XXXX. Up to eight breakpoints can be defined. Only supported for an address located in RAM, so it does not work for address range F000 up to FFFF. At address 0000 no breakpoint can be set. See also command A, C, K or S. |
B ENTER | Display address of all eight breakpoints. |
C | Continue programm execution at current PC location. Any CPU register, incl. This command is only supported after a breakpoint has been hit. PC can be changed with command A in between. See also command A, B, K or S. |
D | Boot from disk in drive #0. |
E | Boot from disk in drive #0. |
G XXXX | Jump to address XXXX. |
K XXXX | Remove breakpoint at address XXXX. If there is no breakpoint set at this address BRP is printed. See also command A, B, C or S. |
L | Load a file in Motorola S-Record format from serial port. This can be used with flexemu on Unix like operating systems by redirecting stdin to a S-Record file when starting flexemu on the command line. See also command R. |
CTRL-L | Clear screen. |
M XXXX | Display and modify memory at address XXXX.
. Redisplay contents of current address (Try with address FD00, it displays the actual seconds of the real time clock). CTRL-J or / Display contents of next address. ^ Display contents of previous address. ZZ Entering a two digit hex number changes the memory at current address. ENTER or CTRL-X Leaving M command. |
R XXXX YYYY | Write a file in Motorola S-Record format to serial port for the given address range incl. address YYYY. This can be used with flexemu on Unix like operating systems by redirecting stdout into a S-Record file when staring flexemu on the command line. See also command L. |
S | Command S: Step over a breakpoint. This command is only supported after a breakpoint has been hit. See also command A, B, C or K. |
T XXXX YYYY | Memory dump from XXXX to including YYYY. |
V | Terminal mode: Any input and output is sent or received from or to serial port. |
. | Continue displaying memory content of current address based on a previous M command or address 0000. |
CTRL-J or / | Continue displaying memory content of next address based on a previous M command or address 0000. |
^ | Continue displaying memory content of previous address based on a previous M command or address 0000. |
ZZ: | A two digit hex number. |
XXXX or YYYY: | A four digit hex address. |
Monitor program U5.4 also contains a terminal emulator. The following control characters are available:
Control character |
Description |
---|---|
CTRL-A | Cursor home |
CTRL-G | give a short terminal bell |
CTRL-H | Backspace |
CTRL-J | Linefeed |
CTRL-L | Form feed, clear screen, cursor home |
CTRL-M | Carriage return |
CTRL-N | Switch cursor on |
CTRL-O | Switch cursor off |
CTRL-Q | Cursor up one line |
CTRL-R | Cursor down one line |
CTRL-S | Cursor right one character |
CTRL-T | Cursor left one character |
ESC or CTRL-[ | Start ESCAPE sequence |
CTRL-] | Toggle between soft- and hard scroll |
The following ESC sequences are available:
ESC sequence | Description |
---|---|
ESC E Y X | Set cursor to line Y and column X. X and Y have an offset of $20 |
ESC F | TODO |
ESC R | Switch inverse character output on |
ESC r | Switch inverse character output off |
X or Y: | Any charcter. |