'===========================================================================
' Subject: SCREEN COMPRESS/DECOMPRESS        Date: 07-11-97 (20:20)       
' Author:  Andrew Below                      Code: QB, QBasic, PDS        
' Origin:  bel@obninsk.ru                  Packet: TEXT.ABC
'===========================================================================
'Screen compress/decompress and horizontal scrool demo.  7/11/97
'---------------------------------------------------------------
'Hi.
'Here is a little screen compress/decompress demo program. I found
'OUT register number, that decreases or increases text scan line flag.
'Just look - it's COOL!
'
'But on my machine, then screen comes up, in the bottom part prints
'strange garbage. If anybody can remove it, please e-mail me how.
'And, If you can tell me, why when screen scrolls horizontally,
'it going up to 1 line, please e-mail me too.
'
'Thanx,
'Andrew.
'E-mail: bel@obninsk.ru
'
DEF SEG = &HB800

SCREEN 0
CLS
FOR a% = 1 TO 23
 LOCATE a%
 COLOR a% MOD 15 + 1
 PRINT STRING$(80, CHR$(a% + 64))
NEXT a%

FOR i = 15 TO 0 STEP -1
  OUT &H3D4, 9
  OUT &H3D5, i
  WAIT &H3DA, 10
  FOR t = 1 TO 4000: NEXT t
NEXT i
FOR i = 0 TO 15
  OUT &H3D4, 9
  OUT &H3D5, i
  WAIT &H3DA, 10
  FOR t = 1 TO 4000: NEXT t
NEXT i
FOR i = 80 TO 0 STEP -1
  OUT &H3D4, 13
  OUT &H3D5, i
  WAIT &H3DA, 13
  FOR t = 1 TO 4000: NEXT t
NEXT i
FOR i = 0 TO 80
  OUT &H3D4, 13
  OUT &H3D5, i
  WAIT &H3DA, 13
  FOR t = 1 TO 4000: NEXT t
NEXT i

DEF SEG
COLOR 15