vax780: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/vax780 - from package: simh

You may install the required package with command apt-get install {package}

Error in other languages:
vax780: bevel nie gevind nie
vax780: comandă negăsită
vax780: comando não encontrado
vax780: commande introuvable
vax780: command not found
vax780: käsku ei ole
vax780: không tìm thấy lệnh
vax780: komanda nerasta
vax780: Kommando nicht gefunden.
vax780: kommandot finns inte
vax780: komut yok
vax780: nie znaleziono polecenia
vax780: níor aimsíodh an t-ordú
vax780: no se encontró la orden
vax780: no s'ha trobat l'ordre
vax780: opdracht niet gevonden
vax780: parancs nem található
vax780: perintah tidak ditemukan
vax780: príkaz nenájdený
vax780: příkaz nenalezen
vax780: команда не найдена
vax780: командата не е открита
vax780: 命令找不到
vax780: コマンドが見つかりません