commit ba7c8d

2026-11-02 08:54:46 Bob Green: -/-

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`programming/sbc3 emulator.md` ..
@@ 11,7 11,33 @@

	## Using the emulator

-	Starting the Emulator with a NetBSD image
+	### ROM image
+	the emulator runs in two different ways:
+	- Boot into the ROM monitor
+	- Load a program (e.g. netbsd) into RAM and run it
+
+	If you wish to run the monitor, you'll need to provide a copy of it. You need to create a folder in the mame tree and put the file in there. Here's what I did:
+	```
+	bob@bsddev2:~/Mame-SBC/mame$ mkdir -p roms/sbc3
+	bob@bsddev2:~/Mame-SBC/mame$ cd roms/sbc3
+	bob@bsddev2:~/Mame-SBC/mame/roms/sbc3$ wget https://mega-micros.co.uk/system_roms/v2.05b118_68681/system_rom_v2.05b118_27c322.bin
+	bob@bsddev2:~/Mame-SBC/mame/roms/sbc3$ ln -s system_rom_v2.05b118_27c322.bin ./sbc3.bin
+	```
+	I use a symbolic link so that's I can have multiple monitors and use the symlink to set a default.
+
+	Starting the emulator with the monitor
	```
	$ ./sbc3-term.sh -hard card.hd -quik netbsd
	```
+
+	Starting the Emulator with a NetBSD image
+	```
+	$ ./sbc3-term.sh -hard card.hd -quik netbsd
+	```
+
+	### Environment variables
+	Some aspects of the emulator can be overwritten using environment variables. See the table below for more details:
+	\| Name \| Function \| Default \|
+	\| :--- \| :--- \| --- \|
+	\| BAUD \| Sets the baud rate for the console port. \| 230400 \|
+	\| JUMPERS \| Change which jumpers (connected to IP0-5 on the duart) a present. Specify a list of numbers, from 0 to 5 inclusive. \| 0 1 2 \|