These are not cheap - but interesting all the same - especially the side-by-side dual 1581 that harks back to the announced but never released 1572 dual 1571 drive.
(attached image is Jan Neuvian's picture of the 1572)n Neuviansan Neuvians Jan Neuvians
https://bitbinders.com/collections/bitbinders-1581-replica-disk-drives
Yes, I thought I saw the software on-line somewhere so that you could copy from one drive to another in the dual 1581.
Ready for the Bay Area Maker Faire tomorrow,
Robert Bernardo
Fresno Commodore User Group - http://www.dickestel.com/fcug.htm
Southern California Commodore & Amiga Network - http://www.portcommodore.com/sccan
It's not a dual-drive assembly in the same vein as, say, an 8250. In a real dual drive, both mechanisms have the same device number (8, 9, etc.) and a specific mechanism is selected in the command string by specifying 0: or 1:, e.g., RUN "1:MY_PROG",8.
In this dual 1581 unit, the two mechanisms have different device numbers, so the CBM DOS commands that could copy from one disk to another in a real dual-drive unit won't work. Any copy program would be working through the serial bus to read from the source disk and write to the destination disk. It could be made to run pretty fast by using the burst mode routines published by Commodore with the Dev-Pak assembler, along with an algorithm that understands the physical disk layout well enough to minimize the effects of rotational latency and track-to-track seeks.
With all that said, the copying speed will be limited to whatever the serial bus can deliver, which won't be nearly as fast as what even the old MSD dual drive could achieve when internally copying from disk to disk.