Beagle Graphics, Double Lo-Res and Virtual ][

["Wayne A. Arthurton" <warthurton@arthurton.com>]

When trying to use Beagle Graphics DGR (double lo-res) on Virtual ][, no matter what I do, ever other column shows a different color.

This is the code I use:

 10  REM  Double Low Res Test
 20  PRINT  CHR$ (4);"BRUN DGR"
 30  &  GR 2
 35  &  COLOR= 5
 40  &  HLIN 0,79 AT 0
 50  &  VLIN 5,15 AT 45

If I run it in Sweet16, the line is solid same color

However, if I manually setup DHR and plot a similar line, the color is uniform

This code:

100 GR
101 POKE 49153,0: REM 80STORE
102 POKE 49234,0: REM NOMIX
103 POKE 49165,0: REM 80COL
104 POKE 49246,0: REM FRCTXT
105 POKE 49236,0: CALL -1998: REM Page 1
106 POKE 49237,0: CALL -1998: REM Page 2
107 POKE 49236,0 : REM Page 1
108 COLOR=3:HLIN 10,20 AT 4
109 POKE 49237,0 : REM Page 2
110 HLIN 10,20 AT 4 

Can anyone give me some insight as to how Beagle's routine differs from the algorithm above.  I would like to email Gerard and see if he can patch it in to work.  

Thanks

Wayne