@bbcmicrobot
#bbcmicrobot MO.1:MOVE0,1023:V.19,1,2;0;19,3,5;0;5:O=0:F.C=0TO1:F.D=0TO105:GC.0,RND(3):P."Error F rc ";:N.::MOVE192,1023:N.:P%=@%:[OPT 2:.a lda#19:jsr&FFF4:lda#6:sta&FE01:lda#19:jsr&FFF4:lda#11:sta&FE01:JMPa:]:?&FE00=12:CA.a
I ran @geoffl's program and got this.
Source: https://bbcmic.ro/?t=baFmB #bbcbasic
Owlet BBC BASIC Editor

#bbcmicrobot MODE0:P.''''"Line smoothing test"''''''''''''''''"Line smoothing test":V.5
DRAW1280,100
MOVE0,100:DRAW1280,200
MOVE-24,512:DRAW1280+24,616
MOVE0,612:DRAW1280,712
P%=@%:[OPT 2:.a lda#19:jsr&FFF4:lda#11:sta&FE01:lda#19:jsr&FFF4:lda#6:sta&FE01:JMPa:]:?&FE00=12:CALLa
I ran @geoffl's program and got this.
Source: https://bbcmic.ro/?t=baTr5 #bbcbasic
Owlet BBC BASIC Editor

#bbcmicrobot
P%=@%:[lda#19:jsr-12:lda&70:sta-511:rts:]
MO.2:F.L=H. TO8^5S.4:!L=RND:N.:?-512=12
?&70=5+RND(11):CA.@%:G.30
#bbcmicrobot P%=@%:[lda#19:jsr-12:lda&70:sta-511:rts:]
MO.2:F.L=H. TO8^5S.4:!L=(RND AND&3F3F3F3F):N.:*FX9,0
GCOL1,8:V.5:P.'" Temporary fault"''" Do NOT adjust"''SPC6"your set."
?-512=12:I=0
REP.I=I+1
?&70=5+RND(11):CA.@%:U.I=102
F.L=0TO7:V.19 L 0;0;19 L+8 7;0;:N.:?&70=11:CA.@%:I=INKEY(102)
F.L=0TO15:V.19,L,L;0;:N.
GOTO40