diff --git a/lib/linguist/heuristics.yml b/lib/linguist/heuristics.yml
index b74fb15dd9..81c3c0cc74 100644
--- a/lib/linguist/heuristics.yml
+++ b/lib/linguist/heuristics.yml
@@ -87,7 +87,7 @@ disambiguations:
   - language: FreeBasic
     pattern: '^[ \t]*#(?:define|endif|endmacro|ifn?def|if|include|lang|macro)\s'
   - language: BASIC
-    pattern: '^\s*\d+'
+    pattern: '^\A\s*\d+'
 - extensions: ['.bb']
   rules:
   - language: BlitzBasic
diff --git a/samples/BASIC/GPIOGW.BAS b/samples/BASIC/GPIOGW.BAS
new file mode 100644
index 0000000000..1550c33b46
--- /dev/null
+++ b/samples/BASIC/GPIOGW.BAS
@@ -0,0 +1,59 @@
+1 REM GWBASIC program to control MCP23S17 I/O expander inside PC Emulator
+10 CLS
+20 REM
+30 REM check for I/O available
+40 IF (INP(&HE0) AND 1) = 0 THEN GOTO 1100
+80 REM
+90 REM Setup Port A and B as Outputs
+100 OUT &HE1, &HFF
+110 OUT &HE2, &HFF
+120 REM
+130 PRINT "on/off Port A and B"
+140 FOR I = 1 TO 4
+150   OUT &HE5, 255
+160   OUT &HE6, 255
+170   FOR D = 1 TO 200: NEXT
+180   OUT &HE5, 0
+190   OUT &HE6, 0
+200   FOR D = 1 TO 200: NEXT
+210 NEXT
+220 REM
+230 PRINT "on/off single GPIO A0 to B2"
+240 FOR I = 1 TO 4
+250   FOR GPIO = 0 TO 10
+260     OUT &HE7, GPIO
+270     OUT &HE9, 0
+280     OUT &HE7, GPIO + 1
+290     OUT &HE9, 1
+300     FOR D = 1 TO 50: NEXT
+310   NEXT
+320   FOR GPIO = 10 TO 0 STEP -1
+330     OUT &HE7, GPIO
+340     OUT &HE9, 0
+350     IF GPIO > 0 THEN: OUT &HE7, GPIO - 1
+360     OUT &HE9, 1
+370     FOR D = 1 TO 50: NEXT
+380   NEXT
+390 NEXT
+400 REM
+410 PRINT "Check for B3 to B7 as Inputs..."
+420 PRINT "Press any key to stop"
+430 OUT &HE2, &H7: REM setup GPIO B3 to B7 as inputs (bits 3..7 = 0)
+440 WHILE LEN(INKEY$) = 0
+450   FOR GPIO = 11 TO 15
+460     GOSUB 1000: REM checkGPIO (gpio)
+470   NEXT
+480 WEND
+490 END
+1000 REM SUB checkGPIO (gpio)
+1010 OUT &HE7, GPIO
+1020 IF INP(&HE9) <> 1 THEN RETURN
+1030 PRINT "pressed "; GPIO; "...";
+1040 WHILE INP(&HE9): WEND
+1050 PRINT "released"
+1070 RETURN
+1099 REM
+1100 REM expander not available
+1110 PRINT "Extended I/O not available on this board!"
+1120 END
+