Hitachi FDD-412A 8 inch floppy drive

m.vgunten
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Location: Bern, Switzerland

Re: Hitachi FDD-412A 8 inch floppy drive

Post by m.vgunten »

max33cs wrote:
Thu Dec 24, 2020 6:57 pm
197 / 5000
Risultati della traduzione
hi, if you managed to get the emulator to work, i want to buy one of these, i have okuma lb12 lathe with osp, year 1987, used this 8 inch reader, wait for your reply thanks
Our 8 inch emulator is currently on hold as we follow another approach. I will inform you as soon as we have found a solution!

mrwing
Posts: 1
Joined: Wed Jan 13, 2021 4:28 pm

Re: Hitachi FDD-412A 8 inch floppy drive

Post by mrwing »

This is really THE thread i have been looking for.
Been all around to see if i can somehow connect a floppy sim to our old OSP5000 mill (MC-6VA).
already looking at different ways to backup the data on the 8" like with Kryoflux and similar tools.
will look forward to the development of this thread.

CNC_USER
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Joined: Sun Apr 18, 2021 1:22 am
Location: Rezekne, Latvia

Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

Hello! :)
I also have OKUMA MC-4VA milling machine which has this Hitachi drive. And how it always happens -system needs to be reloaded. Unfortunately that's not the only problem here- I have found that terminator resistor array inside of floppy drive was crumbled, did find a replacement but drive still isnt working. Im waiting for an FDC floppy controller board to test if the problem possibly is in board. Can I ask m.vgunten to measure resistance between GND and +5V line on FDD-412A board where connectors for floppy and power cable is located?
By the way- in attachements there is FDD pinouts and connections to OSP5000 FDC board that I got from manuals I have for my machine. Hope it can somehow help. One of the possible solutions would be to make a dump from original 8'' floppies and write it to a 3.5'' floppy (OKUMA OSP5000 and OSP5020 systems have an option of FRP board that is used together with 3.5'' drives). Older OKUMAs are beasts- mechanically everything is in perfect state, CNC system also works, only headache is created because of these oldschool 8'' floppies.
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m.vgunten
Posts: 19
Joined: Sat Jan 18, 2020 5:56 pm
Location: Bern, Switzerland

Re: Hitachi FDD-412A 8 inch floppy drive

Post by m.vgunten »

CNC_USER wrote:
Sun Apr 18, 2021 1:41 am
Can I ask m.vgunten to measure resistance between GND and +5V line on FDD-412A board where connectors for floppy and power cable is located?
Unfortunately I don't have access to the drives anymore, but I will see what I can do. Sorry for that.
CNC_USER wrote:
Sun Apr 18, 2021 1:41 am
By the way- in attachements there is FDD pinouts and connections to OSP5000 FDC board that I got from manuals I have for my machine. Hope it can somehow help.
Thanks, this is certainly helpful, for me and other readers!
If your documentation shows some more details about the Hitachi FDD-412A jumper settings (meanings of each jumper) this would be also useful :)

CNC_USER
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Location: Rezekne, Latvia

Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

m.vgunten wrote:
Mon Apr 19, 2021 7:12 am
If your documentation shows some more details about the Hitachi FDD-412A jumper settings (meanings of each jumper) this would be also useful
I have information about jumper settings on different OSP5000 CNC system boards, but unfortunately there is absolutely no info on these drives. :(
m.vgunten wrote:
Mon Apr 19, 2021 7:12 am
Unfortunately I don't have access to the drives anymore, but I will see what I can do. Sorry for that.
Thats ok. I just wanted to compare that resistance. When terminator resistor (completely new) array is installed, resistance between GND and +5V line is suspiciously low- 27 ohms. Even with removed array resistance is approx. 87 Ohms, which is also too low for circuit based on 74LS logic. Capacitors was the first thing I changed- result stay the same. Something is wrong there.
At the moment I have called to a friend asking if he have some spare floppy drive in a factory he works. Really want to get that machine in a working state. Another hope is one of my old friend who owns a private PC museum, maybe he can lend me 8'' floppy I can connect to Kryoflux.

CNC_USER
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Joined: Sun Apr 18, 2021 1:22 am
Location: Rezekne, Latvia

Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

So here is the news: my FDD-412A isn't working (hope it is not one of these HITACHI modules, will look at electronic a bit later), I received an FRP board for OKUMA and 8'' floppy adapter from DBIT. How stupid is an idea of reading data from 8'' floppies (with the help of Kryoflux) and writing that dump to a new 3.5'' disk? I know there is a difference in speeds, what other obstacles can I face here? Floppy controller on FRP board is D72065C.
I know You guys have more experience in these questions. I think together we can come to some result.

m.vgunten
Posts: 19
Joined: Sat Jan 18, 2020 5:56 pm
Location: Bern, Switzerland

Re: Hitachi FDD-412A 8 inch floppy drive

Post by m.vgunten »

CNC_USER wrote:
Sun Apr 18, 2021 1:41 am
Can I ask m.vgunten to measure resistance between GND and +5V line on FDD-412A board where connectors for floppy and power cable is located?
Sorry for my late answer. I'm not sure if this is still of interest ... anyway, a colleague of mine has measured the following values on two floppy drives:
24.7 Ohm
26.4 Ohm

mofugginyeti
Posts: 1
Joined: Wed Sep 22, 2021 6:08 am

Re: Hitachi FDD-412A 8 inch floppy drive

Post by mofugginyeti »

Guess I'm in the old okuma club too.. Any update about an emulator? Got a mc4va and mc5v and need to get the control software backup off a floppy or copied before the inevitable happens. I have 2 sets of backup floppys and a punched tape from okuma. Do any of you guys know if the control software can be loaded from the tape reader? If there's no floppy emulation solution, I want to try a ardunio based tape emulator but still have the problem of getting the data off the floppy disks.

CNC_USER
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Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

mofygginyeti- what control system does Your machine have- OSP5000M-G or OSP5020M-G ? If You have a tapes (there should be 7 in total) then it is possible to load software files if You follow these instructions- see attachements.
I purchased in final new floppy drive to replace non-working from my machine and installed CMOS memory boards in place of bubble memory. Now software loads in a 6-8sec if comparing to 30-40sec when bubble memory was used. Did find old ROBOTRON 8'' floppy drive. Im thinking to use Kryouflux to get files from floppies- just to keep a copy of them.
P.S. I know this is irrelevant question to this topic- but do You guys use an IGF on Your machines (milling ones)? I have a floppies with all needed software, but can't find information how to load IGF. :?
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Khalil
Posts: 3
Joined: Sun Dec 12, 2021 3:12 pm

Re: Hitachi FDD-412A 8 inch floppy drive

Post by Khalil »

I leave you an image of the interface that I got from the person who sold it to me.

https://ibb.co/hVC7pDs

Khalil
Posts: 3
Joined: Sun Dec 12, 2021 3:12 pm

Re: Hitachi FDD-412A 8 inch floppy drive

Post by Khalil »

m.vgunten wrote:
Thu Sep 24, 2020 7:19 am
Dear Joe

Thank you so much for the pinout ... very useful!

If you are able to connect the FDD-412A drive to Standard 34 Pin IDC Connector I am very interested. Please let me know about your solution!
Until now I am not able to handle the data separator pins ...

Thx Martin

Good afternoon, did you make any progress in the connection?

Khalil
Posts: 3
Joined: Sun Dec 12, 2021 3:12 pm

Re: Hitachi FDD-412A 8 inch floppy drive

Post by Khalil »

The Sharp fdd412 floppy drive has an identical jumper configuration in its number of pins, and in the floppy drive that I have in my hands the configuration matches the standard.
Attachments
posibles jumpers.png
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CNC_USER
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Location: Rezekne, Latvia

Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

Want to jump again in discussion- did You guys have any results with the drive? Im trying to get data from installation disks (OKUMA OSP5000M-G), but I cannot figure out- where exactly is DATA READ pin/output. From the pictures here an output shoud be on pin 37 (Data area). But I managed to get something out from disks(that looks like flux stream, but Kryoflux doesnt understand it and thinks that it's unknown data) only on pins 35 (Separated data) and 39 (Separated clock).But if we take a look on circuit fragment which is also here, they are inputs!!! And that circuit is not from this floppy drive- its from device side, not the floppy drive. :shock: And how to understand that note in pinout about pin 37: Used as FILE DATA-N by selecting short plug? Please help- this drive is driving me crazy.
Guntis

Jeff
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Re: Hitachi FDD-412A 8 inch floppy drive

Post by Jeff »

Try to make a preservation stream with the kryoflux and use the hxc software to open the raw files.

CNC_USER
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Re: Hitachi FDD-412A 8 inch floppy drive

Post by CNC_USER »

Situationwith these OKUMA system disks isn't that easy. Only the first track is encoded as FM, all other information is some rather obscure method of encoding. This is how it looks (two separate disks from two different machines, one machining centre with 10 files on it, second from lathe- 18 files on it). Kryoflux understands and decode only first track on both. Both disks arent damaged nor held near any magnetic fields, machines read these perfectly. Problem is in getting out one 256 byte file with machine parameters. :cry:
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