If I understand well, you were trying to create a 80 GB HPFS partition. The biggest HPFS partition is 64 GB. Therefore, either create 2 partitions or use JFS, which does not have the 64 GB limit.
Though HPFS can handle a 64GB partition, I find the most success at about the 50GB range. Also, anything over a certain size reports weird numbers to BootManager (assuming you have it installed) and some third party drive utilities (older - and possibly newer - versions of the disk widget for WPSWizard for instance). In the case of BootManager, you may find that it shows a negative (or some other weird) value for the size of the partition - simply ignore this. For the disk widget for WPSWizard (at least the version I am using - havent bothered checking for an update) it doesnt seem to calculate free space correctly - again, nothing that causes issues.
Also, in doing a long format (assuming you select that), you may find that the format progress goes to 100% and then starts again, finishing at some odd low percentage. Inotherwords:
95%
...
100%
...
5%
...
10%
...
17%
...
Format Complete.
That is apparently "normal" and can be ignored. The disk is being properly formatted and again it simply seems to be an error in calculating the partition size for the status messages which does not seem to affect the actual format operation in any way.
-Rob