WIP quick hack to check keyboard

this for some reason only works ONCE
though I can replicate the logic in BASIC
and it works over multiple keys
not sure what's wrong

mandel.s

@@ -42,6 +42,9 @@ CIX    = $f2 ; u8 - index into INBUFF
 INBUFF = $f3 ; u16 - pointer to ascii
 FLPTR  = $fc ; u16 - pointer to user buffer float48
 
+CH1    = $02f2 ; previous character read from keyboard
+CH     = $02fc ; current character read from keyboard
+
 LBUFF  = $0580 ; result buffer for FASC routine
 
 ; FP ROM routine vectors
@@ -73,15 +76,21 @@ stride = width >> 2
 DMACTL = $D400
 DLISTL = $D402
 DLISTH = $D403
+WSYNC  = $D40A
 
 ; OS shadow registers
 SDLSTL = $230
 SDLSTH = $231
 
 ; interrupt stuff
+SYSVBV = $E45F
 XITVBV = $E462
 SETVBV = $E45C
 
+
+; Keys
+KEY_RIGHT = $07
+
 .struct float48
     exponent .byte
     mantissa .byte 6
@@ -126,6 +135,9 @@ char_map:
         .byte 96 + i
     .endrepeat
 
+hex_chars:
+    .byte "0123456789abcdef"
+
 aspect:
     ; aspect ratio!
     ; pixels at 320w are 5:6 (narrow)
@@ -888,6 +900,33 @@ loop_sx:
     jsr mandelbrot
     jsr pset
 
+    ; check keyboard buffer
+    lda CH
+    cmp #$ff
+    beq skip_char
+
+    ; Clear the keyboard buffer
+    ldx #$ff
+    stx CH
+
+    tax
+    lsr a
+    lsr a
+    lsr a
+    lsr a
+    tay
+    lda hex_chars,y
+    sta temp
+
+    txa
+    and #$0f
+    tay
+    lda hex_chars,y
+    sta temp + 1
+
+    draw_text 14, 2, temp
+
+skip_char:
 
     ; check if we should update the counters
     ;