Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-14, 14:49

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Are you using a suitable 720k floppy that was formatted on a different drive known to be working properly? (I used an original software disk).

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-14, 14:45

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Actually that first pic looks like a perfect read of track 0. The first column (with all the 0's) shows the track ID actually read from the disk. You can ignore the second column which is the sector being read. The third column is the number that matched the seeked track ID; the fourth is those that …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-13, 13:01

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

PS... I've also used ImageDisk on an old 5.25" drive that had an issue with the top and bottom heads being out of alignment with each other. I have to say that it's really VERY satisfying when you successfully realign the heads, hear those high pitched beeps in IMD, and end up with a working drive. …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-13, 12:54

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Alignment using IMD It's actually pretty simple once you get to using IMD. I'd suggest checking out these two links that explain the process quite well - this is what I read first. https://vswitchzero.com/2018/05/07/5-25-floppy-drive-alignment/ (and the old thread link too) And from Dave Dunfield …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-13, 12:48

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

4865 disassembly part 2: This is how it looks with the drive removed. 4865 disassembly 6.jpg Flip it over and remove these two screws holding the drive in the metal bracket. 4865 disassembly 7.jpg Now you can plug the cable and adapter back in and proceed to using IMD to do the alignment. As per my …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-13, 12:39

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

4865 disassembly part 1: A small clip can be seen through the rear vent slots on each side of the drive. Use a small screwdriver or similar to gently press one clip in, while using your other hand to pry the two halves apart (fingernails work, or you could use a pry tool). Then do the other side. …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-13, 11:46

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Sure, no problem... will post a pic soon.

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-12, 06:31

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

If your controller has support for 4 physical drives (like the IBM FDC included with the PC and XT) you can start the program with the switch /4 to enable the menu choices of "C, D" which again, mean units 2 and 3. Thanks for the info... when I first read your reply I was like... wow you've gotta …

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Re: How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2021-04-11, 10:09

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Hi robbo007, Yes, apologies for not mentioning the work that I had to do first, which was making up a custom cable! :-) You're right that IMD won't work with an external drive, so you need to get it connected to a regular floppy controller to be seen as drive A: or B: Background: Internally, the …

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Re: Help fixing rare CL-GD610/620 VGA card

Posted on 2021-04-08, 04:10

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by InbetweenDays

in Marvin \ Video

in Marvin \ Video

The new RAM chips fixed the corruption - well, the vertical lines at least. It's interesting that the dodgy ones work fine with an external display, with no visible artifacts. The only thing left is that dark horizontal line through the middle of the LCD, which I'm assuming to be a problem with the …

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Re: Help fixing rare CL-GD610/620 VGA card

Posted on 2021-02-12, 06:30

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by InbetweenDays

in Marvin \ Video

in Marvin \ Video

Awesome, really glad to hear it @InbetweenDays! I'm curious how your recreation of the -22V PSU goes as that's a weak point of my setup (or any of these) as far as bizarre, unique parts goes. Easy done... grab yourself one of these from eBay: "MC34063A Reverse Voltage Module Positive To Negative …

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Re: Help fixing rare CL-GD610/620 VGA card

Posted on 2021-02-01, 09:48

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by InbetweenDays

in Marvin \ Video

in Marvin \ Video

Good news -- the card is fixed (kinda) and working! But first a big shout out of thanks to incanus and Jonas-fr (Is there a way to tag someone?) -- without your replies I'd not have known that a utility is required to switch output to the external VGA connector (which is a bit weird I must say). It …

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Re: Alesis S4+ vs SC-55 for GM games - Youtube vid

Posted on 2020-11-23, 08:11

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by InbetweenDays

in Marvin \ Sound

in Marvin \ Sound

That demo song still brings back fond memories for me, a quarter of a century later... 😊

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Re: Alesis S4+ vs SC-55 for GM games - Youtube vid

Posted on 2020-11-23, 08:09

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by InbetweenDays

in Marvin \ Sound

in Marvin \ Sound

Yes that's the one I'm comparing. The LSL6 video will show it off well as it sounds amazing & better than the Sc-55 on most of the music in that game.

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Alesis S4+ vs SC-55 for GM games - Youtube vid

Posted on 2020-11-20, 03:09

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by InbetweenDays

in Marvin \ Sound

in Marvin \ Sound

I've just uploaded a comparison video to Youtube for anyone interested... Alesis S4+ versus the SC-55, using Prince of Persia 2. https://www.youtube.com/watch?v=HM5BnGKHAg8 I'm intending to do another comparison using LSL6 when I get around to it... I might take requests for others but no, I'm not …

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Re: NEC Powermate 386/33i running slow

Posted on 2020-10-27, 01:25

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Post detailed photos of motherboard if you can. Forgot to mention that there are no jumper or switch settings related to the cache, just in case that's what you wanted to check. There's some relevant info here . I'll take some pics when I can but in the meantime here's a pic of one from an eBay …

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Re: NEC Powermate 386/33i running slow

Posted on 2020-10-27, 01:20

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Well, if the cache is non-functional, then I could see it benchmarking about the same as a 386-25 with cache. Maybe one of the chips went bad, or needs to be re-seated. Yep, that's the way I'm thinking. Unfortunately the cache chips are soldered on otherwise I'd have tried cleaning / reseating / …

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NEC Powermate 386/33i running slow

Posted on 2020-10-26, 15:26

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Ok, so I've just been through an adventure setting up a Powermate 386/33i... as you'll realise if you read the "how-to" info I've just posted for posterity. :-) The one thing I'm yet to resolve is that it's running quite slowly. (Apparently the Powermate 386s were a bit slow anyway). NSSI benchmarks …

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How-to / info: NEC Powermate 386 BIOS setup utility

Posted on 2020-10-26, 15:11

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

Disclaimer: This information is based on my experience setting up an NEC Powermate 386/33i. It probably also works with other Powermate 386 systems, but anything you do is at your own risk and I take no responsibility for any damage you cause following any of the information in this post. When it …

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How to: IBM 4865 external 720k floppy drive (Alps DFL413C02B) head alignment

Posted on 2020-10-16, 04:36

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by InbetweenDays

in Marvin \ General Old Hardware

in Marvin \ General Old Hardware

I couldn't find this information anywhere else online so after I finally worked it out, I thought I'd post here. This is for the IBM 720k external floppy drive type 4865 as used with the 5160 & 5170. Internally mine uses the Alps DFL413C02B which apparently is the same drive as used with the PS/2 …

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