I recently acquired a SELTRON DD40 External 5.25" Floppy Disk Drive, supposedly for Apple II series machines, however there seems to be a dearth of information around this item when I search for it.
I was wondering if anybody is familiar with these drives and has any information about them?
TIA
There were dozens of different brands of compatible floppy drives back in the day. Chances are it is a fairly formula one. A picture (or three) is woth a thousand words. Does it have a 20 pin IDC connector or a DB19? 1/2 height or full height? Have you opened it up to see what brand of mechanism it uses? There were several popular ones that many of the clone brands used.
OK, so some googling produced this:
https://www.ebay.com/itm/224451035001
That drive looks almost exactly like the ones that VTech (sold under the "Laser" name in the US) out of Hong Kong sold back in the day. The mechanism is a 1/2 height, looks like a Mitsumi or similar asian made one. Connector on the one in the auction is a IDC20.
So basically they are a 99% compatible drive to a Disk ][. One difference is they are normally 40 track capable (vs 36 like most Disk ][ which used a Shugart SA390 mechanism).
I should have it Monday, so I'll get more detail then, but it looks half height and has what appears to be a 20 pin IDC connector. I can't make out the power supply connector, and since it doesn't have a PSU I took a bit of a risk on it, though it only cost £30. Pictures are stolen from ebay, so not great.
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Normally these drives don't need a separate power supply because they are powered over the IDC20 cable. I have no idea what that DIN5 connector is. At first I was thinking Commodore Serial Bus, but that's a 6 pin connector. I'm really curious as to what it is connected to.
It would be really awesome if you wouldn't mind opening up the case and taking some pictures inside.
The ebay link softwarejanitor found seems quite similar to the images Ronin47 provided. softwarejanitor's photo clearly shows a (c) 1983 VTL sticker. VTL (Video Technology Limited) later became Vtech, the maker of the Laser line of Apple // compatible computers. I agree the drive is a generic half height 40 track capable drive, hence the DD40 and not DD35 product name. I sold some like thisaround 1987 from Laser, not SELTRON, which came with an IDC20- DB19 adapter in the box so it could be used with a Disk ][ controller or Apple 5.25 controller or //c or Laser 128.
Regarding the power connector, VTL was pretty bad about using a single case for 5 or six products and just swapping the internals, so it might not be used or even connected to anything. A picture of the internals would be interesting. I bet it has a Mitsumi drive installed.
I also sold VTech stuff back in the 1980s including a few external 5.25" drives that as you say look just like this one except for having a "Laser" label on them. And yes, they did includ a IDC20-DB19 adapter. I think I still have at least one or two of those adapters around somewhere. I think the ones I sold instead of the DIN-5 connector just had a block off plate like the one around where the ribbon cable comes out the back of the SELTRON drive. But your guess it may not be even connected could be correct.
And the ones I sold back in the day, I believe were usually Mitsumi drives.
It arrived today, so will try and get some pictures of inside and out tomorrow and post up here.
Family round today so can't do it today.
Awesome, it will be cool to see the pics.
As promised, here are some photos of the Seltron taken today. The drive itself seems to be in overall great physical condition, bar some yellowing. The case is very solidly built and was made in 1983 by VTL. Serial number is 110060. As usual for something from this era, shielding is completely over the top!!
The DIN plug is 5 pin and seems to be factory fit. 5v & 12V can be found at the socket when connected to my Apple ][e. I suspect if you had it connected to a machine that didn't provide power via the floppy controller (Is there such a thing in the world of Apple?), it would act as a power in connector.
Mechanism is manufactured by Sankyo. The belt seems to be in good condition, not slimy or melting, but dry and nicely tensioned.
If I connect it to port 1 of the FDD controller, it tries to boot, though I don't have a suitable boot disk. I did try to copy a disk from my Floppyemu to a blank unformatted 5 1/4" disk, but it kept showing write fails. A disk speed test also came out very odd, but these problems could be simple to solve since there is very little on the PCB, just 6 ICs 2 of which are 74LS series. Also, I'm still trying to work out what I'm doing having owned the machine for about a month and the FDD since yesterday :)
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Very interesting. Thanks for posting the photos.
No problem :)
So after the weird testing results around RPM, I decided to video the drive during testing, and it looks like I'm getting 75RPM rather then the expected 300RPM.
Back to look at the belt more closely, and while it isn't sticky or melting, it feels dry and stiff, so I don't think it's gripping the drive shaft and drive hub at all well.
New belt is on order now and I'll lubricate the hub and clamp spindles and de-grease the drive parts while I wait for that to arrive. The motor seems to spin ok with the belt removed, so fingers crossed the motor is ok.
The head seems to seek ok and the write protect switch tests fine, so I am hoping the problem is just lack of RPM!
What's interesting is that I had buy a drive belt for a record turntable due to the size.
Possibly this drive was intended for use with computers like the Laser 3000 which were pretty rare in the US. Those were a semi-Apple II compatible, and it is possible that the drive controllers and computer power supplies in some of those machines were marginal enough that an external power supply was a necessity for reliable operation. The floppy drive is one of the biggest power consumers in a typical Apple II system.
Look at the floppy drive pictured in this Laser 3000 ad...
Yeah, that looks suspiciously like mine. You may be right about the PSU too, or maybe the Laser 3000 didn't even have power for the FDD so a separate one was necessary.
Interestingly I found this Dual Drive version with another Laser machine, the design elements are clearly the same and the drive mechanism looks identical.
Laser.jpg
Everytime I think this thread is done, it renews my curiosity. I'll pull my Laser 3000 and floppy out of the closet this weekend and let you know what i find.
Cool, be really interested to know what you have and how it all hangs together :)
Lucky B*****. I always wanted a Laser 3000. Extremely rare over here in the US. Also the later version sold by other companies like the APlus 3000 which was a more //e clone also extremely rare.
VTL ultimately became VTech from what I've read, they've been around a very long time.
That's true, VTL stands for Video Tech Limited I think. They are still around I think, although they haven't made computers in a long time. My house phones are actually from vtech. But I've had those for at least 12 years so not really current.
They also made "unique" systems like the Creativision (Of which I own an example) which is like someone took a ColecoVision, ripped out the Z80 and stuck a 6502 in it's place.
(It has among the worst controllers I've ever used)
https://en.wikipedia.org/wiki/VTech_CreatiVision
Chesh
Struggling to get a suitable drive belt for the Seltron, the length/diameter is fine, but getting one with the correct width is all kinds of fun :(
That is super cool. Never saw one of those here in the US. The other Laser and VTech products like the Laser 200, Laser 300 were very rare here. I've also never actually seen a Laser 2001, which was apparently the computer version of the CreatiVision.
Well, it still isn't working, but Isorted out a few things today with the Seltron FDD.Number 1 was that the drive motor pulley was either not as clean as I originally thought it was, or it's picked up a load of junk as a result of me playing around with the replacement belts.As I was planning to lightly sand it anyway, I took the motor out for better access and got it cleaned and sanded.I also disassembled the whole top hub that grips the disk and cleaned it with IPA, re-lubed the bearings, and reassembled, and at the same time removed the main drive-wheel off the bottom of the drive hub and cleaned, re-lubed all the bearings for that and re-assembled with the now lightly sanded drive wheel which is more grippy now.So, drive wheel and hub assy all spin nice and freely now, though I am still getting drive belt slippage. More on that later.Next, I did a random capacitor removal from the motor control board, and the cap was reading half it's stated value, so now I don't trust any of the caps on there and have ordered replacements. Annoyingly I can't find my big box o' caps, as it's in another box somewhere after moving house, meaning ordering more!!! One looks quite nasty, and the heat shrink has split so it needs to go.Now, slippage. The new belts I got are not fabric reinforced, so have a bit of stretch in them, and don't work very well, so my hunt goes on. I do have some more coming, but they may suffer the same fate. The original belt does drive the disk, but is still slipping on the motor pulley. It isn't slipping on the disk drive pulley, probably because a) I sanded it and it's quite grippy b) there is a much larger surface area to grip.Whilst running a Locksmith speed test, I used a smooth bar to tension the belt and seemed to have some luck in increasing the overall speed, but I think until I know the caps for the motor control board are good, then I won't necessarily be getting a useful result.Of note, the motor does have additional mounting holes to adjust the tension, and whilst it is now at maximum, I may just be able to tweak it to add a little more.One other thing that did spring to mind is that I'm wondering if the motor drive pulley originally had a rubber coating, now long gone, to help avoid slippage? I haven't seen it before, but I suppose it is possible, as the spindle is not much wider than the motor spindle itself.On another positive note, I have at least worked out how I can trim the 4mm belts down so they fit ok!
Hi,
DD40 floppy drive is for the VZ200 / VZ300 / Laser210 / Laser310 / Salarion fellow / Texet TX8000A, Smart Alec Jr, and Seltron computers. All are pretty much the same thing, just rebranded. Z80 based computers.The "VZ" , "Sanyo" and "Laser" branded drives were all DD40's, ran at 75rpm, using a simpified FM format. 80Kb per side floppy disks. The electronics within were never designed to work with the Apple or compatible computers. The CAT (Laser3000) computer disk drive used the exact same case, but had Apple compatible componentry inside (300 rpm etc)
There are a multitude of VZ/Laser enthusiasts that would pay handsomly for your Seltron drive in working condition.
/dave
Australia
The one he has is definitely the Apple compatible version, you can tell by the IDC20 cable. The other versions for the Z80 machines would have used a 34 pin cable. You can see in the pics the little add-in panel with the cutout for the narrower cable too.
Hi,
Forgot to answer the bit way above about the 5 pin DIN connector. Its for +5v and +12v power for this drive configured for the Z80 machines.
I reckon I'll come across as being "that person", which is not my intention.
The drives for the Selton , VZ and Laser computers all have the IDC20 cables. (I have three drives so can confirm they are not 34).
I would have thought a Seltron Floppy Drive would be for acomputer that is named ' Selton'.75 rpm screams that it is for a VZ/Laser/Seltron as well, rather than Apple.Anyhoo, I no doubt am wrong and will now go away. Good luck with it in any case.
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You may be right... I've never seen an MFM or FM encoded floppy drive that used an IDC connector. Then again the VZ series machines were kind of weird. And not at all common in the US. I have a couple of VZ200's but neither of them work. I have seen a floppy drive that used that same case molding that had the same power connector and a 34 pin cable. Instead of the plastic framed drive chassis it was aluminum though, I think a Mitsumi if I remember right. And I think some of the Lazer marked drives which were for the Apple compatibles had the power connector because the older Lazer 3000s I don't think had a very big power supply and probably would have been greatly taxed running two floppy drives. The clone makers re-used all kinds of components like cases almost willy-nilly between different lines, which makes things super confusing sometimes. Somone on one of the other forums posted what looked like an MSX computer but the board inside was actually an Apple clone.
As for the brand names... Apple clone parts, at least here in the US were sold under all sorts of brand names, including some that were also used to market CP/M computers or parts.