Kernel: n8vem-mark4: Fix timer interrupt rate

diff --git a/Kernel/platform-n8vem-mark4/kernel.def b/Kernel/platform-n8vem-mark4/kernel.def
index 9f1741d..c48fab5 100644 (file)
--- a/Kernel/platform-n8vem-mark4/kernel.def
+++ b/Kernel/platform-n8vem-mark4/kernel.def
@@ -1,5 +1,6 @@
 ; UZI mnemonics for memory addresses etc
 
+; Move down to 0xF600 to fit the monitor in
 U_DATA                      .equ 0xF800       ; (this is struct u_data from kernel.h)
 U_DATA__TOTALSIZE           .equ 0x300        ; 256+256+256 bytes.
 Z80_TYPE                    .equ 2
@@ -12,9 +13,9 @@ Z180_IO_BASE                .equ 0x40
 MARK4_IO_BASE               .equ 0x80
 
 ; No standard clock speed for the Mark IV board, but this is a common choice.
-; Move down to 0xF600 to fit the monitor in
 USE_FANCY_MONITOR           .equ 1            ; disabling this saves around approx 0.5KB
 CPU_CLOCK_KHZ               .equ 36864        ; 18.432MHz * 2
+Z180_TIMER_SCALE            .equ 20           ; CPU clocks per timer tick
 TICKSPERSEC                 .equ 40           ; timer interrupt rate (Hz)
 
 PROGBASE                   .equ 0x0000