HP-IB, Amigo/cs80 was Re: hp 9153 floppy & disk

That would seem to be a good idea. I would suggest that the HPIB interface be buffered (using either the 75160/1/2 series of chips, which would use 2 devices, or 4 off 3448 or similar.). As I mentiond a few weeks back it is a lot easier to replace a buffer chip than a microcontorller iff something goes wrong). There should be no broblem with 'banging' the handshake on microcontroller port lines. HP haev been known to do this. IIRC you need a very small maount of external logic (let me check) to ensure one signal changes fast enough. It's only a couple of TTL chips, though (and common ones, like 74x00), not really worth putting in a PLD. HPIB would take 16 port lines of the microcontroller + 2 or 3 to control the buffer driection. And then you need however many port lines it takes to talk to the flash memroy device. As regards code size, IIEC, the HP9133H (SS/80 protocol) has 16K of 6809 conde in it. That should give you some idea as to the complexity. The Commodore and HP command sets are very different. The major difference is that Commodore drives are file-oriented devices (you open a file by name, you can get a directory, etc), while HP devices are block oriented (you ask to read a particular block on the disk, the host OD reads the appropratie blocks to read the directory, then finds the blocks that comprise the file you want, and reads those, etc). Yes, I know the Commodore drives let you read disks at hte block level, but most of the time you didn't do that. H -tony