Use of DSKO$ with POWR-DOS -------------------------- The DSKO$ function of POWR-DOS has the general syntax: DSKO$ SW, SE, AD where o SW is a Switch (SW=0 for read from disk to RAM; SW non-zero for write from RAM to disk) o SE is the disk sector number operated on (0 to 79) o AD is the start (low end) of the RAM block used as a buffer; must be 1292 bytes long and cleared before use -- e.g., CLEAR 0, MAXRAM-1292. This command allows POWR-DOS to pull in a sector from disk, modify individual bytes, or groups of bytes (up to a sector in length), and write the modified sector back to the disk. This function requires that the disk be formatted, but not that there be a directory. This would seem to allow some pseudo-formatting, to get sub-sectors ("blocks") on the disk. For example, each 1292 byte sector could be considered as a set of four 323 byte blocks (320 total blocks on a disk); since 1292 factors into 4*17*19, there are other possibilities. Each block could be used as a data "record" (without a directory structure, a dedicated data base is about the only application I can think of for a disk used this way). Each block could hold it's block number (may not be needed) and data in a format determined by a (to be developed) data base program. With SE as the sector number, the block number would be given by 4*SE+OF, OF is an offset within each sector (OF is 0 to 4, in the above example). Bytes within a block would be identified by an index BT (0 to 322 in this case). Although this has some interest, I'm not likely to pursue it further myself -- since data bases on the Model 100 are not an interest of mine (my data bases are all too big to fit even on a Chipmunk disk!). A down side of this is that the total sector must be read and written to replace any one of the blocks -- suggesting a four-times speed-up if the disk were truly formatted into smaller sectors. From the published data, TS-RANDOM (Traveling Software) appears to do just that. BUT -- although I have not tried it, the POWR-DOS manual says that disks formatted with FORMAT.BA (part of the POWR-DOS package) will accept sector (DSKO$) writes almost 20 times faster than normally formatted disks -- so long as they have not been written to by any file based command. Phil Wheeler [71266,125] Torrance, CA 10/11/86