start of tape loading. hw works and have a generation script

2026-10-03 16:29:41 +02:00
parent 47fffc2e71
commit 5897e55094
16 changed files with 784 additions and 106 deletions
@@ -0,0 +1,50 @@
+.include "bios.inc"
+
+.area   TAPELOAD (ABS)
+.org    TAPE_LOADER_ROM_ADDRESS
+
+COMP_PORT       =     0x18
+
+WORK_BASE       =     0x0B000
+LOAD_START      =     0x08000
+LOAD_LIMIT_HI   =     0x0B0
+STACK_TOP       =     0x0BFFF
+
+OLD_SP          =     WORK_BASE+0x00
+
+start:
+        ld      (OLD_SP), sp
+        ld      sp, #STACK_TOP
+
+        di
+
+poll_loop:
+
+        ; Read from the hardware port COMP_PORT
+        in      a, (COMP_PORT)
+        out     (COMP_PORT), a
+        
+        ; Save the raw port status in register B
+        ld      b, a
+
+        ; Print a carriage return '\r' (ASCII 0x0D)
+        ld      a, #0x0D
+        call    BIOS_PUTC
+
+        ; Restore the port status and isolate the relevant bit
+        ; (Assuming bit 0 determines 0 or 1; adjust 'and' mask if it is a different bit)
+        ld      a, b
+        and     #0x01
+
+        ; Convert the binary 0 or 1 into ASCII '0' (0x30) or '1' (0x31)
+        add     a, #0x30
+        
+        ; Print the '0' or '1' character
+        call    BIOS_PUTC
+
+        ; Infinite loop: poll continuously
+        jr      poll_loop
+
+        ld      sp, (OLD_SP)
+        ei
+        ret