Execute this TLC script from within the console. Next start the basic program This will allow you to control openMSX with Basic.

TCL code

proc openmsxcontrol {} {
	#scaler factor
	if {[peek 0xc000]==1} {set ::scale_factor 1}
	if {[peek 0xc000]==2} {set ::scale_factor 2}
	if {[peek 0xc000]==3} {set ::scale_factor 3}
	#Scaler Algotithm
	if {[peek 0xc001]==1} {set ::scale_algorithm simple}
	if {[peek 0xc001]==2} {set ::scale_algorithm Sai}
	if {[peek 0xc001]==3} {set ::scale_algorithm ScaleNx}
	if {[peek 0xc001]==4} {set ::scale_algorithm hq}
	if {[peek 0xc001]==5} {set ::scale_algorithm hqlite}
	#scanline
	set ::scanline [peek 0xc002]

	after time 1 openmsxcontrol
}

Basic Code

10 screen0:width80:keyoff:cls
11 s=0
15 ?"Scaler Factor     "
20 ?"[1] Scale Factor 1"
30 ?"[2] Scale Factor 2"
40 ?"[3] Scale Factor 3"
50 ?"------------------"
55 ?"Scaler Algorithm  "
60 ?"[Q] Simple        "
70 ?"[W] Sai	       "
80 ?"[E] ScaleNx       "
90 ?"[R] HQ	       "
95 ?"[T] HQLite        "
96 ?"------------------"
97 ?"[+] More Scanlines"
98 ?"[-] Less Scanlines"
100 a$=inkey$
101 if a$="1" then poke &hc000,1
102 if a$="2" then poke &hc000,2
103 if a$="3" then poke &hc000,3
104 rem renderers
105 if a$="q" then poke &hc001,1
106 if a$="w" then poke &hc001,2
107 if a$="e" then poke &hc001,3
108 if a$="r" then poke &hc001,4
109 if a$="t" then poke &hc001,5
110 if a$="+" then s=s+1
111 if a$="-" then s=s-1
112 if s>100 then s=100
113 if s<0 then s=0
114 poke &hc002,s
210 if a$=chr$(32) then end
211 goto 100

Fun!