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Re: Microdrive Unit Design

Posted: Sun Oct 08, 2017 12:44 pm
by Cristian
Derek_Stewart wrote:replaced the Microdrive unit, with a QLSD. I have never needed a Microdrive since 1990s.

Indeed I think almost nobody needs Microdrives, since they got disk interfaces many years ago.
We're simply discussing about the different mdv unit designs.

Re: Microdrive Unit Design

Posted: Tue Oct 10, 2017 10:00 am
by tcat
Hi,

I was thinking to run `QL health clinic' for all those unwanted microdrives. Some may prove beyond repair, those fixed can be offered back on owner's behalf to QL community to save on postage.

Tom

Re: Microdrive Unit Design

Posted: Tue Oct 10, 2017 8:54 pm
by Cristian
RWAP wrote:Now the less common microdrive unit with straight edges - note the extra red wire on the PCB

My straight-edged units have two red wires. Also I noticed that all these units have only one screw at one corner. The other corner has the hole but no screw.
After several trials I can confirm that their performances are far better than the other keyed-edge units in my possess, both from a mechanical and logical point of view. The cartridges runs smoother with low noise, they can read/write and format faster and better.
Of course this is only my case and counts relatively. I'll share some pictures soon

Re: Microdrive Unit Design

Posted: Tue Oct 10, 2017 8:55 pm
by Cristian
tcat wrote:Hi,

I was thinking to run `QL health clinic' for all those unwanted microdrives. Some may prove beyond repair, those fixed can be offered back on owner's behalf to QL community to save on postage.

Tom

Interesting idea

Re: Microdrive Unit Design

Posted: Thu Oct 12, 2017 1:06 pm
by Cristian
Dave wrote:
Ralf R. wrote:
RWAP wrote:And....making the motor a bit faster (I think there was a potentiometer on the PCB) gives more sectors. So I think, one of your mdv is running a bit faster than the other. I was able to get 235 sectors, but had not used this speed.


This is the opposite of my experience.


I remember the early '90 "Apple Super(floppy)Drive". The more the heads went to the external of the disk, the slower the motor turned.

Re: Microdrive Unit Design

Posted: Fri Oct 13, 2017 12:45 pm
by tcat
extra red wire.


Hi, I thought these wires supply power to the motor, correct?

Tomas

Re: Microdrive Unit Design

Posted: Fri Oct 13, 2017 8:46 pm
by Cristian
tcat wrote:
extra red wire.


Hi, I thought these wires supply power to the motor, correct?

Tomas

Yes I think you're right. Those wires connect to a completely different part of the PCB in comparison with the "standard" mdv units. I'll post some photos ASAP

Re: Microdrive Unit Design

Posted: Sun Oct 15, 2017 8:52 am
by Cristian

Re: Microdrive Unit Design

Posted: Sun Oct 15, 2017 9:35 am
by Derek_Stewart
Hi,

Nice photographs.

One thought occurred to me, is it possible to replace the MDV Tape reader with a more up to date reader?

Not sure what I mean here, just wondering if there is a replacement Tape reader or maybe something else.

Re: Microdrive Unit Design

Posted: Sun Oct 15, 2017 8:49 pm
by tcat
Cristian wrote:As promised, here are some (mediocre) photos of my straight-edged Mdv units:


Hi,

Straight edged ones are usually Iss#5, the ones on your pictures might be even pre-Iss#5 ones, as they do not have two mods applied, two diodes and one track cut from the rear of the head board assembly.

Keyed edged are usually Iss#6 and higher. Visual difference is also motor power black/red leads being connected from different parts of the headboard.

Another clue, Iss#6 and higher have insignia below one of the headboard mounting screws. It would interesting to see, what issue insignia you can read on your keyed edged drive?

Higher sector count during format may not possibly be too beneficial, as may result in poorer compatibility with other drives, or with the very same drive in the long run.

I have coded `mSpeed', a small tool indicating drive speed, that came underway when programming `mDoubler' mDump1,2 tape cloner/dumper/duplicator.

EDIT disclaimer, I might not be entirely precise up to the point, as I can only draw on experience with my two QL internal drives, plus two Iss#5 (kindly provided by RWAP), and another two Iss#6 (kindly provided by Derek), for my tests. I 've also had once Iss#7 unit on loan.

Tom