No definitions found for 'IBM 1800'
Perhaps one of these:
ibneiah,
ibm 701,
ipm,
ibm 1403,
ibm 1620,
iwbni,
ibm 704,
ibm 801,
ibm 7090,
ibm 370,
ibm 650,
ippm,
ifna,
ibm 3720,
ibm390,
ivanhoe,
ibn,
ipn,
ibm,
ibfn,
ifiom,
iwfm,
ibm 7094,
ibm 7040,
ipomoea,
ibm 2741,
ipmi,
ivan,
ibm 1710,
ibm 360,
i-beam,
ibm 705,
ibm 1130,
ibm 709,
ivan iii,
iban,
ibm 3270,
ivm