thanks - didn't know about showbootcodes, it confirmed they were being passed correctly.
But I've found the problem - I just needed to put waitusb=5 before tce=sda1. I think this is important because tc is on the SD card of my asus eeepc 1000h
Also, to keep my slackware and tc options separate, I moved the append command into the tinycore section of lilo.conf rather than adding to the append in the global section. Now that hda=noprobe is not being set, tc can now see all my sata hard drive partitions as hda1, hda2 etc. - previously tc could only see the single partition on my SD card.
So this is a new issue - shouldn't my sata hard drive be sda and the SD card sdb? This is what the hda=noprobe is for in slackware?