Another C1P build

[ronin47]

Thanks!

I searched and searched, but couldn't find gerber files for the Klyball D-13 V2.0 data separator pcb.
So, I contacted Mr. Klyball himself, to request the files...
He did not provide a link to the gerber files, but instead, provided a link to the online PCBWAY website that will produce a minimum batch of 5 PCB's. https://www.pcbway.com/project/sharepro ... 1cc3b.html

Having no other option, I ordered 5 pcb's from PCBWAY. (shipping cost was DOUBLE the cost of the boards )
The process was quite seamless: the boards arrived after 8 days, without issue.
I populated all 5 boards.
I sold one to a forum member. Shipping cost (DHL with tracking), for that ONE populated pcb, to Georgia USA from South Africa was $40!!!

H.

Thanks so much, I'll have a look I'll likely order 5 from PCB way and then sell the spares to recoup a little cash.

[HOWARDHB]

Hurrraaaay!

The MPI 51 floppy drive arrived this afternoon.

Using the Greaseweasle, I wrote C1P-OS65D_3.36_Tutorial5.HEF to a new floppy in the MPI 51...


IT BOOTS UP PERFECTLY!

MPI 51 WORKS.jpg (396.16 KiB) Viewed 5163 times

[bxdanny]

Congratulations again.

I'm wondering if, when you use a 5.25" disk drive with the Klyball A-13 board, the head loads and unloads when the disk is accessed, or if it stays constantly loaded like the MPI drives with the internal data separators did when connected directly. I presume the motor still spins continuously.

[HOWARDHB]

When either the MPI 51 or the Teac FD-55 is connected to the D-13 data separator, the head is permanently loaded and the motor runs continuously. (On the Teac FD-55, the motor starts when the door latch is closed, but the MPI 51's motor runs regardless of the door/ latch)

I note that there is circuitry (re-triggerable monostable 74LS123) on the Klyball D-13 that, if jumpered correctly, would stop the motor from running a few seconds after the INDEXOUT signal toggles, but I have not yet tested it.

MOTOR.png (287.64 KiB) Viewed 5189 times

[HOWARDHB]

Now that the the OSI 610 disk "system" is working flawlessly, I turned my attention to the SAMSUNG SFD-321J 3.5" stiffy drive that I could not get to work...

I measured the index pulse frequency, to determine the disk RPM, when connected to the data separator:
It is 6 Hz, which is 360 RPM !!!!
All of the OSI disk images (.hfe) that I have, specify 300rpm and are FM "encoded" at 250Khz data/clock rate.

Q: How to make the 3.5" Samsung drive run at 300rpm, with NO rpm "jumpers" or "solder bridges" on the little drive's pcb?

Well, after dowloading and reading the spec. sheet, I discovered that the rpm of the drive is controlled by the the disk media itself.
I read that high density disks will run at 360rpm/500Khz data rate, and standard density disks run at 300rpm/250KHz, which is exactly what we need!

But how does the drive know what density disk is inserted???

Turns out, the drive has a sensor, (opposite the "write protect" notch) that detects the inserted media's density!
All I had to do, to have a working stiffy drive, was to cover the hole in the HD disks that I had on hand, thereby "tricking" the drive to run at 300rpm!

HIGH DENSITY.jpg (277.48 KiB) Viewed 5135 times

Now I have a working 3.5" disk drive too!!!

STIFFY WORKS.jpg (255.34 KiB) Viewed 5135 times

I was able to copy (disk to disk) all the 5.25" disks that I have working in the MPI 51 drive, by utilising the OSI disk copy function on OS65d 3.3 Tutorial Disk #5, to new 3.5" disks!!! (connected as drive "D" - no twist in the floppy cable)

Copying to/from the GOTEK, also works flawlessly!!!

What remains now is to make the enclosure that I've designed....


H.

[ronin47]

Definitely getting a buzz to get my 610 built now!!! Time to start a build box with all the parts

I've added 5 data separator PCBs to my cart at PCBWay, just waiting for the order to be reviewed.

EDIT - order is processing

[HOWARDHB]

Awesome!

Note that the Klyball data separator uses a SN74121 and NOT a normal TTL 74LS121 !

H.

[ronin47]

Awesome!

Note that the Klyball data separator uses a SN74121 and NOT a normal TTL 74LS121 !

H.

I'll tap you up for more info once I get building, but appreciate the tip

I need to start counting sockets on the 610 so I can get some ordered and start my build box. Probably have all the rest of the passives in stock, but I'll need to order more RAM, hopefully the same seller on Ali Express has more as all the ones I got worked just fine. Hopefully I'll have most of the logic IC's, though I don't have a 74121, I know that for sure.

I'm also going to be building a Cosmac Elf II https://github.com/awasson/AVI-ELF-II and I've just finished a Z80-MBC2.

Wish me luck!!!

[HOWARDHB]

Good luck!

[ronin47]

Good luck!

Thank you sir!