Extra tools



Peter Barney,

Letchworth,

Hertfordshire.



Users of Bobby Rao's toolkit machine-code routines for the

Spectrum - page 77, February, Your Computer - may find

these routines useful also. List 3 and 4 are high-resolu-

tion left and right scrolls, but in each case, the byte

listed as 55 or 63 - use only one - will scroll with wrap-

around if 63, or with a white pixel from left or right, as

appropriate, if 55. This same byte poked 0 gives inverse

characters with wrap around.

  List 1 and 2 are high-res up or down scrolls, which may

be of interest as they are much shorter - 53 and 55 bytes -

than the 99 and 97 of the published routines.