Another disk imaging project

On Wed, 3 Aug 2005 10:27:01 -0500 Patrick Finnegan <pat at computer-refuge.org> wrote: I think the beauty of an open design is that you in particular don't have to be capable or motivated to build the hardware yourself, but there are multiple other people who are capable and (possibly) willing to build one for you. A 'closed' design lives and dies at the whim of the person who designed (and built) it. A publised 'open' design constructed with TTL gates could, for example, be constructed by someone who prefers CMOS or ECL (!) who is motivated to adapt the design. (I know, as a packrat with a huge junkbox, that when I see a logic circuit I want to build I always immediately begin adapting it to the TTL I happen to have on hand.) ----------- (stepping into a discussion where I am a latecomer, and don't mean to step on feet or exceed my expertise)- Isn't a disk controller really just a specialized logic state machine? When I studied the 1771 in tech school I remember it as being fairly rudimentary stuff, i.e. nothing that a general purpose Micro couldn't be coerced into doing. In fact, the whole reason for the dedicated controllers of the past was that when the whole system's 'brain' was just a Z80 or 6800 (or even just a 6502) processor, a hardwired 'dedicated peripheral controller' design was the only way to 'extend the machine' to do as complex a task as control a floppy drive. These days, we're not so resource-starved that the machine it's 'plugged into' only has a simple 8-bitter as it's sole CPU (i.e. the Z80 chip isn't a $75 item that the whole rest of the machine surrounds,) so it seems like if all the resources of a Z80, or a PIC, or similar processor were thrown at the task, with some additional generic (i.e TTL gates) hardware outboard, it could be a highly flexible controller. (pardon my processor bias in the above. plug in your favorite arch. as desired)