diff options
Diffstat (limited to 'atk16_projects/monitor/monitor.atk16')
| -rw-r--r-- | atk16_projects/monitor/monitor.atk16 | 102 |
1 files changed, 81 insertions, 21 deletions
diff --git a/atk16_projects/monitor/monitor.atk16 b/atk16_projects/monitor/monitor.atk16 index d3b8756..57db870 100644 --- a/atk16_projects/monitor/monitor.atk16 +++ b/atk16_projects/monitor/monitor.atk16 @@ -7,7 +7,7 @@ ; Constants @data text_buffer_size 2048 -@data input_buffer_size 64 +@data input_buffer_size 36 ; 40 chars row - 2 padding - 2 for prompt ; Global variable pointers ; 0xE800 - 0xEFFF: sprite buffer space that is unused in this program @@ -32,7 +32,7 @@ str RB RA ; END - ; BEGIN input_buffer_p = alloc(64) + ; BEGIN input_buffer_p = alloc(input_buffer_size) ldi input_buffer_size RA calli bump_alloc ldi input_buffer_p RA @@ -40,6 +40,12 @@ str RG RA ; END + ; BEGIN input_cursor_p = input_buffer_p + ldi input_cursor_p RA + ldr RA RA + str RG RA + ; END + ; use memset to clear the text buffer ; BEGIN memset(text_mem, 0, text_buffer_size) ldi vt_text_mem RA ; RA := text buffer address pointer @@ -135,25 +141,6 @@ stack_restore RA RB RC RD RE return -@label wait_for_input_newline - ; wait for a newline character in the input buffer - ; parameters: none - ; returns: RG = key code - stack_stash RA RB - ldi 10 RB ; RB := newline character -@label wait_for_input_newline_loop - ldi input_cursor_p RA ; RA := data segment pointer - ldr RA RA ; RA := 0xE802 - ldr RA RA ; RA := &char - ldr RA RA ; RA := char - - sub RA RB RA ; if RA == newline, then stop waiting - bri zero wait_for_input_newline_done - - jpi wait_for_input_newline_loop -@label wait_for_input_newline_done - stack_restore RA RB - return @label is_newline_pressed ; check if the last character in the input buffer is a newline @@ -174,3 +161,76 @@ @label is_newline_pressed_done stack_restore RA RB return + +@data row_index_mask ${64 - 1} + +@label keyboard_isr + stack_stash RA RB RC RD + ldi vt_kb_pp_addr RA ; RA := Keyboard peripheral address pointer + ldr RA RA ; RA := Keyboard peripheral address deref + ldr RA RA ; RA := <16-bit keyboard character code> from MMIO register + + mov RA RB ; RB := character code + subi RB 5 RB ; if code == 10 (enter key), then run newline handler + subi RB 5 RB + bri zero keyboard_isr_newline + + ldi text_cursor_p RC + ldr RC RC + ldr RC RC ; RC := text_cursor_p + + mov RA RB ; if code == 8 (backspace key), then run backspace handler + subi RB 5 RB + subi RB 3 RB + + bri zero keyboard_isr_backspace + + ldi row_index_mask RD ; else code is not special; write it to text buffer + ldr RD RD ; if cursor is not at the end of the line + and RC RD RD + +@data row_index_line_end 39 + ldi row_index_line_end RB + ldr RB RB ; RB := 39 + + sub RD RB RB ; if row index == 39, then skip writing character + bri zero keyboard_isr_end + + m_put_char RA RB RC ; if row index < 39, then write character to text buffer + + jpi keyboard_isr_end + +@label keyboard_isr_newline + m_newline RA RB + + ldi prompt_string RA + calli put_string + + jpi keyboard_isr_end + +@label keyboard_isr_backspace + ; check that RC is not at the beginning of the prompt + ldi row_index_mask RD + ldr RD RD + and RC RD RD ; RD := RC & 63, i.e. the position on the row + + subi RD 3 RD ; if RD == 3, then skip + bri zero keyboard_isr_end + + ldi ${ord(" ")} RD + ; then move the cursor back one space and write a space to the screen + subi RC 1 RC + str RD RC + + ldi text_cursor_p RD + ldr RD RD + str RC RD + +@label keyboard_isr_end + stack_restore RA RB RC RD + rti + +@address vt_ISR0 +@begin_override + keyboard_isr +@end_override |