InstallRAMISR - Revision history

Aoineko at 23:05, 8 June 2022

2022-06-08T23:05:49Z

Aoineko at 23:00, 8 June 2022

2022-06-08T23:00:51Z

Aoineko at 22:55, 8 June 2022

2022-06-08T22:55:02Z

Aoineko at 22:54, 8 June 2022

2022-06-08T22:54:47Z

Aoineko: Created page with "This Build tool option allow cartridge program to use page #0 (address 0000h~3FFFh) as RAM. This gives almost 16 KB more memory. If `InstallRAMISR` is set to 1, th..."

2022-06-08T22:54:16Z

Created page with "This Build tool option allow cartridge program to use page #0 (address 0000h~3FFFh) as RAM. This gives almost 16 KB more memory. If <tt>InstallRAMISR</tt> is set to 1, th..."

New page

This [[Build tool]] option allow cartridge program to use page #0 (address 0000h~3FFFh) as RAM. This gives almost 16 KB more memory.

If <tt>InstallRAMISR</tt> is set to 1, the cartridge boot code will automatically switch page #0 to the same slot as page #3 (where RAM is located), then copy a ISR (Interrupt Service Routine) at address 0038h. This ISR handle VDP's V-Blank interruption (each 50/60 Hz) and call an handler function that program must provide: <tt>void VDP_InterruptHandler();</tt>

Warnings:
* This option only work on MSX with at least 64 KB of RAM (otherwise, there is no RAM on page #0).
* Obviously, no BIOS function can be used in this program (unless you reswitched the Main-ROM on page #0 first).

← Older revision		Revision as of 23:00, 8 June 2022
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	* This option only work on MSX with at least 64 KB of RAM (otherwise, there is no RAM on page #0).		* This option only work on MSX with at least 64 KB of RAM (otherwise, there is no RAM on page #0).
	* Obviously, no BIOS function can be used in this program (unless you reswitched the Main-ROM on page #0 first).		* Obviously, no BIOS function can be used in this program (unless you reswitched the Main-ROM on page #0 first).
		+
		+	You can check the [[Samples#Software_Sprite\|Software Sprite]] sample program for a use example.

@@ Line 2: / Line 2: @@
   :: Set RAM in slot 0 and install ISR there (0=false, 1=true)
-  set InstallRAMISR=0
+  set InstallRAMISR=1
 If <tt>InstallRAMISR</tt> is set to 1, the cartridge boot code will automatically switch page #0 to the same slot as page #3 (where RAM is located), then copy a ISR (Interrupt Service Routine) at address 0038h. This ISR handle VDP's V-Blank interruption (each 50/60 Hz) and call an handler function that program must provide: <tt>void VDP_InterruptHandler();</tt>

← Older revision		Revision as of 22:54, 8 June 2022
Line 1:		Line 1:
	This [[Build tool]] option allow cartridge program to use page #0 (address 0000h~3FFFh) as RAM. This gives almost 16 KB more memory.		This [[Build tool]] option allow cartridge program to use page #0 (address 0000h~3FFFh) as RAM. This gives almost 16 KB more memory.
		+
		+	:: Set RAM in slot 0 and install ISR there (0=false, 1=true)
		+	set InstallRAMISR=0

	If <tt>InstallRAMISR</tt> is set to 1, the cartridge boot code will automatically switch page #0 to the same slot as page #3 (where RAM is located), then copy a ISR (Interrupt Service Routine) at address 0038h. This ISR handle VDP's V-Blank interruption (each 50/60 Hz) and call an handler function that program must provide: <tt>void VDP_InterruptHandler();</tt>		If <tt>InstallRAMISR</tt> is set to 1, the cartridge boot code will automatically switch page #0 to the same slot as page #3 (where RAM is located), then copy a ISR (Interrupt Service Routine) at address 0038h. This ISR handle VDP's V-Blank interruption (each 50/60 Hz) and call an handler function that program must provide: <tt>void VDP_InterruptHandler();</tt>