dave@zehntel.UUCP (Dave Funk) (08/17/87)
1581 drive ---------- I have noticed that there is a new Commodore 1581 3.5" disk drive. Apparently, its capacity is on the order of 800K. Does anybody know anything more about this drive? Is it a 'fast' drive (1571-like)? Copying disks ------------- It seems that the 'COPY' command for the C128 will not copy from drive to drive. In fact, the Programmer's Reference Guide claims it can't be done (???). The 'BACKUP' command only works on a dual drive. So what do you do if you have two single drives and want to copy all files from one to the other? -- Dave Funk ....!ucbvax!zehntel!dave Zehntel, Inc. ....!decvax!sytek!zehntel!dave 2625 Shadelands Drive ...."zehntel!dave"@BERKELEY Walnut Creek, CA 94598 (415) 932-6900 x309
sentinel@killer.UUCP (The Sentinel) (08/19/87)
In article <320@zehntel.UUCP>, dave@zehntel.UUCP (Dave Funk) writes: > > 1581 drive > ---------- > I have noticed that there is a new Commodore 1581 3.5" disk drive. > Apparently, its capacity is on the order of 800K. Does anybody know > anything more about this drive? Is it a 'fast' drive (1571-like)? The 1581, as you mentioned, is a 3.5" drive with around 800k (give or take a few) of capacity. It is double-sided. It supports fast serial and burst modes like the 1571. It uses a standard MFM controller chip instead of a custom Commodore GCR controller, so it should be reasonably compatible with MS-DOS and maybe Amiga formats (I'm not sure if anyone has actually done any disk transfer yet, but it should be possible). The 1581's DOS has been rewritten (since the 1581 is quite unlike any Commodore drive in the past), and now allows you to partition the disk into sections. Each partition can be "formatted" to contain its own directory. Each directory (including the main one) holds 296 entries. The 1581 contains an area of RAM that is used as a full track cache. When a sector is requested, the controller reads the entire track in one pass. Then, subsequent sectors from the same track are taken from RAM instead of the disk. This speeds things up significantly, especially directory access... now, opening the last file in the directory takes just as little time as opening the first. All in all, a very nice drive. > Copying disks > ------------- > It seems that the 'COPY' command for the C128 will not copy from drive > to drive. In fact, the Programmer's Reference Guide claims it can't > be done (???). The 'BACKUP' command only works on a dual drive. So > what do you do if you have two single drives and want to copy all files > from one to the other? You've just run into one of the remnants of the PET. To make a long story short, the BASIC disk access commands correspond to the DOS commands. SCRATCH"name" is the same as "s0:name", RENAME"from" TO "to" is the same as "r0:to=from", and so on. These commands come from PET BASIC 4.0. Anyway, the COPY command in BASIC corresponds to the c0: command in DOS. The DOS copy command can only copy within the same device... not too useful on a single drive. The BACKUP command simply issues the "b" command to the drive, which on a dual drive copies one disk to the other. On a single drive this is impossible. The amount of work necessary to copy between two devices is much larger than the amount of work necessary to do the same thing between the drives in a dual drive. With the dual drive, you issue a command and let the DOS do the work. With two single drives, the DOS cannot do this, so the computer must perform the copying itself. I would advise you to invest in a good copying program. Something like Fast Hack 'Em or C-128 Cannon. Those are the only two that I know of that support the 1571 and C-128. Pick one you like... all of the commercial copiers I have seen include a whole-disk copier and a file copier. And PLEASE don't use it to make illegal copies of stuff you don't own... if you like a program, you should buy it. 'Nuff said on that topic... I don't want to start another flame war about protection and piracy. > -- > Dave Funk ....!ucbvax!zehntel!dave > Zehntel, Inc. ....!decvax!sytek!zehntel!dave > 2625 Shadelands Drive ...."zehntel!dave"@BERKELEY > Walnut Creek, CA 94598 (415) 932-6900 x309 -- Rob Tillotson ...ihnp4!killer!sentinel 3922-1 Newport Ave. -or- Fort Wayne, IN 46805 ...rutgers!unirot!sentinel (219) 483-2722 (top one preferred)