Re: MFM drive gone nuts

On 2014-07-20 at 19:46:23, MikeS (dm561@torfree.net) wrote:

> I really get a little annoyed sometimes by this de rigeur childish
> IBM-bashing, especially when the 'basher' doesn't seem to understand what
> he's calling "utterly sick", "PC-crap", "stupidity" etc.
>  
> First of all, the twisted cable is only required with a PC-compatible
> *FLOPPY* drive controller; hard disks can be (and usually are) connected the
> 'standard' way with straight-through cables and drive selected with one of
> four possible jumpers/switches.
>  
> Note that if you do choose to use a twisted HD cable (which allows
> moving/swapping drives without having to worry about changing DS settings)
> the 'twisted' wires are *not* the same as in a floppy cable.
>  
> Also note that this technique of Cable-Selecting drives by their _position
> on the cable_ that you find so "stupid" (as opposed to having to set arcane
> switches/jumpers on each drive) was also used with IDE drives, especially on
> the later boards using 80-conductor cables.
>  
> As to the "utterly sick" and "stupid" twisted *floppy* cable, not only did
> it allow installing/swapping drives without changing any jumpers or
> switches, but it was an IMO ingenious way around the issue that most drives
> of
> the day had no provision for individually controlling the drive motors;
> select one drive and its motor and all other drives on the bus would spin
> (with unnecessary wear on disks and drives and wasting considerable power).
>  
> The "PC-crap"py twist allowed using the unused drive 3 and 4 select lines to
> individually control the motors in drives 1 and 2.

I am sorry but we shall have to "agree to disagree" and keep our opinions. Seeing the cut'n twisted cables makes me sick. Made me back in the days and every reminder of this brings the same feelings. Not only it caused the problem that drive address was depending on the position on the cable (!) rather than what I wanted it to be and I cut more than enough times my hands/fingers trying to route cables inside those cheap metal cases, in the REQUIRED order of connectors (when the drives COULD NOT be reodered in the case due to size difference or customer's preferences for example) but AFAIR effectively disallowed the use of more than two drives! It could have been done by the book and without cutting and twisting cables as Amiga design shows us. No, Amiga didn't have problems because of that. The problem was that this [..] PC approach caused the twisting of not only the cable but the whole connecting standard. Instead of deciding myself which drive is which and having up to four of them if needed, it enforced often unroutable configurations.  The lack of jumpers and provision for individual motor control is the result of this, not the cause. They were just not needed.

Using CS (cable select) as an OPTION on IDE harddrives makes much more sense, because a) there were never more than two and b) they don't have to be addressed by "master" or "slave" and they don't have to be externally accessible.

P. S. I am sorry if I offended your feelings on the ingenuity of this approach. I shall try to keep my emotions and opinions more on a leash.

--  
SD!

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