INT 16 - KEYBOARD - SET TYPEMATIC RATE AND DELAY
AH = 03h
AL = subfunction
00h set default delay and rate (PCjr and some PS/2)
01h increase delay before repeat (PCjr)
02h decrease repeat rate by factor of 2 (PCjr)
03h increase delay and decrease repeat rate (PCjr)
04h turn off typematic repeat (PCjr and some PS/2)
05h set repeat rate and delay (AT,PS)
BH = delay value (00h = 250ms to 03h = 1000ms)
BL = repeat rate (00h=30/sec to 0Ch=10/sec [def] to 1Fh=2/sec)
06h get current typematic rate and delay (newer PS/2s)
Return: BL = repeat rate (see above)
BH = delay (see above)
Note:   use INT 16/AH=09h to determine whether some of the subfunctions are
supported

See also: 1609

1603 - KEYBOARD - SET TYPEMATIC RATE AND DELAY