A computer simulation, utilizing the Landau-Lifshitz-Gilbert equation, of ultra-high- density recording on continuous longitudinal media is carried out. The two important features of this work are the use of a planar-type head, which enables a high write field of 14183 Oe ts be generated at the center of the recording medium, and the media with very high coercivities up to 13010 Oe. From a systematic investigation, it is found that the optimum write field is higher than the medium coercivity by only 3400 Oe over a wide coercivity range. This new finding allows one to write an a medium with a very high coercivity by using a planar-type head. It is demonstrated that a reasonably good bit pattern with a bit density of 605 kfci is generated on the medium with a coercivity of l1720 Oe, and, combined with a high track pitch density of 100 ktpi, a recording density of 60 Gb/in² can be obtained in a single layer medium. With an improved write- head designs even a higher recording density of 75 Gb/in² may be possible since comparison of the results for the bit pattern from the present head profile and the ideal Lindholm profile indicates an increase in the track pitch density of about 20%. Even at this density, the thermal stability parameter (KV/kT) at room temperature is high enough (60) to provide ample room for thermal stability.