Pi Boot (Rainbow colored screen like Raspberry Pi boot) | MSX-BASIC version 3+ https://msxjpn.jimdofree.com/%E3%83%97%E3%83%AD%E3%82%B0%E3%83%A9%E3%83%A0/yjk-%E8%A1%A8%E7%A4%BA/

piboot.bas

' Pi Boot (Rainbow colored screen like Raspberry Pi boot) | MSX-BASIC version 3+
' Copyright (c) 2019-2024 BALLOON | FU-SEN
' The MIT License (MIT) - https://mit.balloon.net.eu.org/#2019-2024
100 DEFINT A-Z
110 C=15*8:'Y*8
120 SCREEN 12
130 COLOR 255,0,0
140 CLS
150 FOR X=32 TO 223 STEP 4
160 K=(X-32)*64/192-32
170 LINE(X  ,0)-(X  ,211),C+(K AND 7)
180 LINE(X+1,0)-(X+1,211),C+(K AND 56)/8
190 NEXT X
200 FOR J=-32 TO 31
210 Y=106-(J+1)*212/64
220 LINE(34,Y)-(34,Y+3),C+(J AND 7)
230 LINE(35,Y)-(35,Y+3),C+(J AND 56)/8
240 NEXT J
250 FOR X=38 TO 223 STEP 4
260 COPY(34,0)-(35,211)TO(X,0)
270 NEXT X
280 GOTO 280