una posible respuesta podria ser la siguiente:
'Código para transmitir
Dim FileName As String: FileName = "C:\BinFiles\Test.Exe"
Dim Offset As Long
Dim FileData As Byte
Open FileName For Binary Access Read As #1
For Offset = 1 To FileLen(FileName)
Get #1, Offset, FileData
MSComm1.Output = Chr$(FileData)
Next Offset
Close #1
'Código para recibir
'Se asume que File #1 ya ha sido abierto en alguna parte del código y
'que ByteCount ha sido declarado como Long e inicializado a 0.
Private Sub MSComm1_OnComm()
Dim TmpStr As String
Dim StrLen As Long, I As Long
Dim FileData As Byte
If MSComm1.CommEvent = comEvReceive Then
While MSComm1.InBufferCount > 0
TmpStr = MSComm1.Input
StrLen = Len(TmpStr)
For I = 1 To StrLen
FileData = CByte(Asc(Mid(TmpStr, I, 1)))
ByteCount = ByteCount + 1
Put #1, ByteCount, FileData
Next I
TmpStr = ""
Wend
End If
End Sub
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