pbm_write.bas

1 REM *****************************
2 REM Procedure to store content of
3 REM graphics memory in graphics
4 REM mode GR.8+16 (320x192x1bpp)
5 REM into standard PBM file.
6 REM *****************************
7 REM
8 REM
9 REM
10 DIM FILENAME$(20)
20 FILENAME$="H:TEST.PBM"
30 GRAPHICS 8+16
40 COLOR 1
50 PLOT 0,0:DRAWTO 319,191
55 PLOT 319,96:DRAWTO 319,191
56 PLOT 223,191:DRAWTO 319,191
60 PLOT 319,96:DRAWTO 319,191
70 PLOT 223,191:DRAWTO 319,191
80 CIRCLE 20,20,10
90 EXEC WRITE_PBM
999 STOP 
10000 ------------------------------
10010 REM Store video RAM
10020 REM in graphics mode #8 into
10030 REM PBM (Portable BitMap) file
10035 REM
10040 REM Filename is to be provided
10050 REM via FILENAME$ variable
10055 REM (Example: "H:TEST.PBM")
10060 ------------------------------
10070 PROC WRITE_PBM
10075   OPEN #1,8,0,FILENAME$
10079   REM PBM HEADER: BINARY FORMAT
10080   PRINT #1;"P4";
10085   PUT #1,13
10089   REM BITMAP RESOLUTION
10090   PRINT #1;"320 192";
10095   PUT #1,13
10130   SCREEN_BEGIN=DPEEK(88)
10135   SCREEN_END=SCREEN_BEGIN+7680-1
10139   REM WRITE VIDEO RAM TO FILE
10140   FOR I=SCREEN_BEGIN TO SCREEN_END
10145     PUT #1,PEEK(I)
10150   NEXT I
10160   CLOSE #1
10200 ENDPROC