| 04988 |  (Attn?) | Sets carry when ATTNFLG<> 0. | 
| 0CA60 |  ATTNchk | ATTN exit check with restoreiram | 
| 009A5 |  Debounce | Scans keyboard until no more
 instabilities detected
 returns a map of the pressed keys
 in A.W
 48G[X+] Keymap nibbles:
 (Nibble: [Bit1 Bit2 Bit3 Bit4])
 0: [ON + SPC .]
 1: [0 ' - 3]
 2: [2 1 A RS]
 3: [* 6 5 4]
 4: [MTH LS / 9]
 5: [8 7 SIN alpha]
 6: [BackSp DEL EEX +/-]
 7: [ENTER 1/x y^x SQRT]
 8: [TAN COS right down]
 9: [left EVALSTONXT]
 A: [up VARCST PRG]
 B: [F E D C]
 C: [B none none none]
 49G Keymap nibbles:
 0: [ON RS LS alpha]
 1:
 2: [right down left up]
 3:
 4: [A B C D]
 5: [E F none APPS]
 6:
 7: [EEX y^x HIST MODE]
 8: [0 1 4 7]
 9: [+/- SQRT CAT TOOL]
 A: [. 2 5 8]
 B: [1/x SIN EQW VAR]
 C: [SPC 3 6 9]
 D: [X COS SYMB STO]
 E: [ENTER + - *]
 F: [/ TAN BackSp NXT] | 
| 04999 |  KeyInBuff? | Carry if true | 
| 00C74 |  OnKeyDown? | Carry if true | 
| 00C80 |  OnKeyStable? | Carry if true | 
| 00D57 |  Flush | Flushes key buffer. | 
| 00D8E |  FlushAttn | Flushes attn counter. | 
| 04840 |  POPKEY | ( -> C.A ) Sets carry if buffer
 is empty.Else returns key in
 C.B (and in @KEYSTORE)
 Uses: A.S C.S C.A D1 (sets P=0) | 
| 007B5 |  SrvcKbdAB | ( A.W -> ) Sets KEYSTATEand
 KEYBUFFER |