Category : BASIC Source Code
Archive   : QBFAQR01.ZIP
Filename : PCXREAD.BAS

'From: BRENT ASHLEY
'Subj: PICTURES WITH QBASIC
'---------------------------------------------------------------------------
'Here's a PCX loader I found and played with some time ago. There are no
'comments and I'm not sure about converting to other screen modes, but
'it's a start and you're welcome to it. For speed, you'll want to either
'modify this to write to an invisible page and then make the page visible
'(apparent speed), or find a library with PCX routines (some of Tom
'Hanlin's have them) written in assembler.

DEFINT A-Z
DECLARE SUB PCXLOAD (File$)

CLS
PCXLOAD "MyFile.PCX"
WHILE INKEY$ = "": WEND

SUB PCXLOAD (File$) STATIC
SCREEN 11, , 0
OPEN File$ FOR INPUT AS #1 LEN = 16384
SEEK #1, 129
DEF SEG = &HA000
FOR ScrLin = 0 TO 479
Addr& = 80& * ScrLin
LinStrt& = Addr&: LinEnd& = Addr& + 80
Plane = 1
OUT &H3C4, 2: OUT &H3C5, Plane
DO WHILE Plane <= 8
Byte = ASC(INPUT$(1, 1))
IF EOF(1) THEN EXIT FOR
IF (Byte AND 192) <> 192 THEN
POKE Addr&, Byte
Addr& = Addr& + 1
IF Addr& >= LinEnd& THEN
Addr& = LinStrt&
Plane = Plane * 2
OUT &H3C4, 2: OUT &H3C5, Plane
END IF
ELSE
Byte = Byte AND 63
Byte2 = ASC(INPUT$(1, 1))
IF EOF(1) THEN EXIT FOR
FOR Expand = 1 TO Byte
POKE Addr&, Byte2
Addr& = Addr& + 1
IF Addr& >= LinEnd& THEN
Addr& = LinStrt&
Plane = Plane * 2
OUT &H3C4, 2: OUT &H3C5, Plane
END IF
NEXT
END IF
LOOP
NEXT
OUT &H3C4, 2: OUT &H3C5, &HF
DEF SEG
CLOSE #1
END SUB

' end of program