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--- vc-3_system_interrupt_table [2026/01/21 01:40] – appledog
+++ vc-3_system_interrupt_table [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-= VC-3 System Interrupt Table
-The VC-3 is a system, running on the SD-8516.
-== Introduction
-I guess this interrupt system is part of the KERNAL, so should be more "VC-3" as it is system software. What follows is a simple list of the interrupt, what it does, it's calling parameters and it's return codes. I guess this should be called "Stellar BIOS V1".
-== Calling Convention
-Each INT subsystem has it's own convention. However, the INT 05h system was done first so it represents a general convention you can expect going forward.
-Parameters:
-- Function number: `AH`
-- Small values: `AL`, `B`, `C`
-- Pointers: `ELM`, `ELD`, `ELX` (EL-group)
-Returns:
-- Values: `B` (or `A` if needed)
-- Status: Carry flag
-- Updated pointers: Same register (ELM/ELD)
-Example Code:
-<codify armasm>
-LDAL #'A'
-LDB #1234
-LDAH $11        ; VAR_SET
-INT $05
-LDELD @string
-LDAH $62        ; IO_GETNUM
-INT $05
-; B has parsed number
-</codify>
-== INT 10h - Video Services
-    ; ============================================================================
-    ; INT 10h - VIDEO SERVICES
-    ; Stellar BIOS Video interrupt handler
-    ; ============================================================================
-    ; Function dispatch via AH register:
-    ;   AH=00h: Set video mode
-    ;   AH=01h: Set cursor shape (reserved)
-    ;   AH=02h: Set cursor position
-    ;   AH=03h: Get cursor position
-    ;   AH=0Eh: Write character at cursor (teletype)
-    ;   AH=0Fh: Get current video mode
-    ;   AH=13h: Write string at cursor
-    ;   AH=14h: Scroll screen up
-    ;   AH=15h: Clear screen
-    ;   AH=16h: Get video parameters (rows, cols)
-    ; ============================================================================
-=== AH=00h: Set video mode
-* Returns: AL is 00 on success, 01 if the mode failed to init.
-Available modes:
-* Mode 0: 22x23 console
-* Mode 1: 40x25 console
-* Mode 2: 80x25 console
-* Mode 3: still thinking, graphics, or superterminal? 1280x800 "128x40"font via 10x20 charset??
-=== AH=01h: Set cursor shape
-=== AH=02h: Set cursor position
-=== AH=03h: Get cursor position
-=== AH=0Eh: Write character (teletype)
-=== AH=13h: Write string
-== INT 11h - Keyboard Services
-=== AH=00h: Read character (non-blocking)
-* returns character code in AL and keyboard flags in BL.
-=== AH=01h: Read character (blocking)
-* returns character code in AL, keyboard flags in BL, and time spent waiting in ms in C
-=== AH=02h: Get keyboard flags
-* returns keyboard flags in AL.
-=== AH=03h: Check if key available
-* returns the number of keys waiting in AL. I.E. 0=no keys available, 1+= has keys waiting.
-== INT 12h - String Services
-=== AH=00h: strlen
-=== AH=01h: strcpy
-=== AH=02h: strcmp
-=== AH=03h: strcat
-=== AH=04h: atoi
-=== AH=05h: itoa
-== INT 13h - Math Services
-=== AH=00h: Multiply 16-bit
-=== AH=01h: Divide 16-bit
-=== AH=02h: Random number
-=== AH=03h: Absolute value
-== INT 14h - Memory Services
-=== AH=00h: memcpy
-=== AH=01h: memset
-=== AH=02h: memcmp
-== INT 15h - File/Storage (future)