[cctalk] Re: ESDI drive imaging
Den sön 23 apr. 2023 kl 08:34 skrev Christopher Zach via cctalk < cctalk@classiccmp.org>: > Not that I know of. Esdi has a much faster data rate and I think that > outstrips the BBB solution. > Not necessarily. Yes, data rates are faster in ESDI. Up to 24 MHz and perhaps higher. But in ESDI the data separator is in the drive. The interface has a Data signal AND a clock signal so it is just a matter of storing a bit on a clock edge. The MFM emulator needs to oversample the data signal greatly to be able to decode the data correctly using the software MFM decoder. That would not be necessary with ESDI. But there are a number of complications with ESDI. Firstly there are both hard sector and soft sector formats and then not all soft sector formats are identical so using a different controller than which was used to format a drive is likely to be difficult. A reading device need to understand the format since the Read gate signal need to be enabled and disabled at certain times to allow for the data separator to resync in the gaps between sectors so the method used by the BBB solution to just read everything into a buffer at high speed for later processing wouldn't work AFAIK. To some extent the older SMD interface is similar to ESDI. Both have the data separator in the drive. Both have hard and soft sector formats. The difference is how commands are sent to the drive. SMD uses a parallel bus and tag while ESDI uses serial signalling. I have seen a device which interfaces an ESDI drive while providing a SMD interface to the host. /Mattis > C > > On April 22, 2023 6:18:39 PM EDT, Dennis Boone via cctalk < > cctalk@classiccmp.org> wrote: > >I think I know the answer to this, but just in case: > > > >Is there a way to image ESDI disks other than to hook them up to their > >usual host controller and use the host? E.g. for MFM, I'd grab the MFM > >Emulator board. > > > >Cheers, > > > >De >
[cctalk] Re: ESDI drive imaging
Not that I know of. Esdi has a much faster data rate and I think that outstrips the BBB solution. C On April 22, 2023 6:18:39 PM EDT, Dennis Boone via cctalk wrote: >I think I know the answer to this, but just in case: > >Is there a way to image ESDI disks other than to hook them up to their >usual host controller and use the host? E.g. for MFM, I'd grab the MFM >Emulator board. > >Cheers, > >De
[cctalk] Re: ESDI drive imaging
On 4/22/23 17:14, r.stricklin via cctalk wrote: > > I can’t say that’s been my experience. I guess I've led a sheltered life. I will say that some ESDI controllers do have a bewildering variety of configuration options. And the Q for the DTC 6280 does confirm your experience. http://www.franken-online.de/ymmv/files/DTC_Q So, I spoke too quickly. Nevermind. --Chuck
[cctalk] Re: ESDI drive imaging
> On Apr 22, 2023, at 4:44 PM, Chuck Guzis via cctalk > wrote: > > On 4/22/23 15:18, Dennis Boone via cctalk wrote: >> I think I know the answer to this, but just in case: >> >> Is there a way to image ESDI disks other than to hook them up to their >> usual host controller and use the host? E.g. for MFM, I'd grab the MFM >> Emulator board. > > In my experience, you can use any ESDI controller--the drive has much of > the logic on it, similar to IDE, but not quite as integrated. I can’t say that’s been my experience. ok bear.
[cctalk] Re: ESDI drive imaging
On 4/22/23 15:18, Dennis Boone via cctalk wrote: > I think I know the answer to this, but just in case: > > Is there a way to image ESDI disks other than to hook them up to their > usual host controller and use the host? E.g. for MFM, I'd grab the MFM > Emulator board. In my experience, you can use any ESDI controller--the drive has much of the logic on it, similar to IDE, but not quite as integrated. --Chuck
