Classic Computer Magazine Archive COMPUTE! ISSUE 61 / JUNE 1985 / PAGE 10

Runaway IBM Keys

My new PCjr is great except for one irritating feature. When I rest my finger on a key, the computer prints a long line of identical letters. When I press the backspace key to erase the extra letters, it repeats, too. How can I stop this repeating feature, or at least slow it down?

Peter Gliewell

You can find the answer to this and many other questions about IBM Personal Computers in the new book from COMPUTE! Publications, Mapping the IBM PC and PCjr by Russ Davies. Most microcomputers supply a repeating function for only a few editing keys such as the cursor controls or space bar. The PCjr has what IBM calls a typamatic keyboard: Nearly every key repeats when you hold it down. (The exceptions are keys such as Enter, which you would never want to repeat.)

Depending on your tastes, the typamatic function is either a godsend or a curse. The following program slows down or eliminates your PCjr's typamatic function:

100 PRINT "Enter a number to
    adjust typamatic"
110 PRINT " 0 - Return to n
120 PRINT " 1 - Increase in
    itial delay"
130 PRINT " 2 - Half rate o
    f repeat"
140 PRINT " 3 - Both 1 and
    2 above"
150 PRINT " 4 - Typamatic f
    unction off"
160 INPUT X : IF X<0 OR X>4 GOT
    O 160
170 X = X * 2 : DEF SEG = 0
180 Y = (PEEK (&H488) AND (&HFF-
190 POKE &H488, (Y OR X)
200 PRINT "PCjr typamatic fun
    ction now adjusted"

The typamatic function uses two different time delays. There is a short initial delay between the time you first press a key and the time it begins to repeat. After repeating begins, there is another slight delay between each repetition. The program lets you adjust either or both of these delays. Note that the typamatic function affects the entire keyboard: If you turn it off, none of the keys—including the space bar and cursor controls—will repeat.