Slimline gotek drive hardware configuration

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mikeyp
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Slimline gotek drive hardware configuration

Post by mikeyp » Sat May 11, 2019 5:17 pm

So, I’ve flashed my 4th gotek drive with hxc2001 firmware, except this one is a slim one. It’s flashed perfectly and loaded the firmware. I’ve even attached a display. It displays hxc, loads an image as expected but doesn’t communicate with the laptop. I’ve remove resistor RA as suggested here https://torlus.com/floppy/forum/viewtopic.php?t=2019 but it still gives an error on the computer.

I think it’s a hardware issue rather than a firmware issue, hopefully wrong jumpers.

Here is a picture of what I’ve done so far.
6F171DD7-9B79-41E5-9938-11A3478BEA08.jpeg
6F171DD7-9B79-41E5-9938-11A3478BEA08.jpeg (111.38 KiB) Viewed 1500 times
Thank you

Jeff
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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sat May 11, 2019 7:42 pm

You must disable the JA input with this hardware. You can disable the JA input with the custom firmware service :

https://hxc2001.com/custom_fw/

Uncheck the "Extra Select button" option and request the new firmware.
(if possible Place back the RA resistor).

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sat May 11, 2019 10:27 pm

I have replaced RA, made the custom firmware as recommended and flashed it to the device. It still is unable to read from the disk. By the way, the toshiba unit does work with its original floppy drive.
D399F19E-8C51-444F-A63D-A0C6757755E6.jpeg
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Please note, the placement of the display is obviously temporary until it’s all working.

Jeff
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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sat May 11, 2019 11:40 pm

Which file image are you using ?
Is the red led is lit when the try to access the drive ?

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sun May 12, 2019 10:45 am

They're the same .HFE files you helped me fix last time. https://torlus.com/floppy/forum/viewtop ... 767#p19767 These work fine on the standard gotek units.

I think the red LED is the error LED. It blinks once each second when no USB is attached, stops once an image is loaded and blinks once when changing image. It doesn't reflect typical floppy usage. I think perhaps I need to add the second LED as per the other thread linked in my first post.

I think it's more the machine than the gotek drive. It's almost like it's not getting a signal its expecting. I found this post/thread which somewhat describes the issue with a similar machine. http://www.vcfed.org/forum/showthread.p ... post447504 Can the gotek generate a ready signal?

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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sun May 12, 2019 11:30 am

mikeyp wrote:
Sun May 12, 2019 10:45 am
I think it's more the machine than the gotek drive. It's almost like it's not getting a signal its expecting. I found this post/thread which somewhat describes the issue with a similar machine. http://www.vcfed.org/forum/showthread.p ... post447504 Can the gotek generate a ready signal?
I think that this is the issue. The 26 pinout have some more signals than the 34 pins version. Some machines may need them, but currently this is not yet handled by the firmware.

Have a look to this https://hxc2001.com/download/floppy_dri ... al_ENG.pdf
Page 16.

I must know where are going the signals "READY_26P" (pin 8 ) , "DINST" (pin 11), FLOPPY_READY (pin 6)
also interested to know if the pin 7 & 13 are connected.
Do you think to able to do such reverse engineering ?

If not, please scan me in very good quality the top and bottom of the board. i want something good enough to be able to follow the traces on the pictures (using a scanner is better).

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sun May 12, 2019 5:11 pm

I'll have a go.

Pin 6 - Connects to 1K resistor PU2. which is connected to +5V on a rail that travels underneath and via the + terminal of C19, back to Pin 1. It also drops through before PU2, travels along the back, before coming back up and connecting to Mosfet Q6, then 1K resistor RN6, then Pin 12 of chip 74HC04D. Pin 13 of 74HC04D then disappears back under the board before re-emerging and connecting to PIN 59 of the ARM chip. It follows the same path as PIN 2 of the standard floppy connector on this diagram. https://torlus.com/floppy/forum/viewtop ... 998#p15834

Pin 7 - Not connected

Pin 8 - Connects to 1K resistor PU3 which is connected to +5V. It also drops through before PU3, travels along the back, before coming back up and connecting to Mosfet Q4, then 1K resistor RN4, then Pin 8 of chip 74HC04D. Pin 9 of 74HC04D then disappears back under the board before re-emerging and connecting to PIN 55 of the ARM chip. It follows the same path as PIN 34 of the standard floppy connector on the diagram linked.

Pin 9 - Connects to 1K resistor PU14 which is connected to +5V. It also drops through before PU14, travels along the back via jumper JE which connects to VSS pulling it low.

Pin 11 - Connects to 1K resistor PU4. which is connected to +5V. It also drops through before PU4, travels along the back via jumper JD which connects to VSS pulling it low.

Pin 13 - Not Connected

I like electronics but I'm not very good, so I'll scan the board on the good quality copier at work on Monday anyway so you can confirm what I've found.

By the way, I'm not sure about your pinout in the PDF. It doesn't agree with the gotek, or the posts here https://torlus.com/floppy/forum/viewtopic.php?t=1932 and here http://old.pinouts.ru/HD/26pin_microfloppy_pinout.shtml which is why I've traced pins 6,8 and 9.

Edit:
I've since found this statement here https://retrocomputing.stackexchange.co ... s-disabled which might explain the different pinouts:
Ready was traditionally the signal that went active after the motor had been turned on and two index holes had passed. So it primarily indicates that a disk is present, and also implies that the drive has had time fully to accelerate.

IBM redefined that pin to indicate disk change — it goes inactive when a disk is ejected and active again when the head steps a track.

I would dare imagine the resistor allows you either to pick a behaviour, or to intermingle them; a combination of both tests works on some machines.

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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sun May 12, 2019 7:01 pm

This is quite interesting.

The name in my pdf is in shugart mode. When you use the pc mode, the pin "FLOPPY_READY" pin become a disk change pin.

Have you tried to change the density jumper (JE) ?

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sun May 12, 2019 7:37 pm

Removal of JE gives no change. The computer still says "Not ready reading drive A"

Jeff
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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sun May 12, 2019 10:04 pm

mikeyp wrote:
Sun May 12, 2019 7:37 pm
Removal of JE gives no change. The computer still says "Not ready reading drive A"
You probably need to change the pin 8 (pin 34) output setting. Use the hxc software to generate a custom config file.

Should be something like this :
setting.png
setting.png (32.83 KiB) Viewed 1440 times
Don't hesitate to change the pin 34 setting since i am not sure about the right polarity (nReady or Ready...) ...

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sun May 12, 2019 10:25 pm

Jeff wrote:
Sun May 12, 2019 10:04 pm
Don't hesitate to change the pin 34 setting since i am not sure about the right polarity (nReady or Ready...) ...
nReady was just the trick! It works!

In summary, the following worked:
  • Custom firmware with "Extra Select Button" Disabled.
  • Everything else default (Jumpers S1, JD and JE connected).
  • Custom config file as in the above post but with nReady for pin 34 (pin 8 on a 26 pin device)
Thank you again!

Would you still like the scans of the circuit tomorrow?

Jeff
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Re: Slimline gotek drive hardware configuration

Post by Jeff » Sun May 12, 2019 10:56 pm

Nice ! :D
mikeyp wrote:
Sun May 12, 2019 10:25 pm
Would you still like the scans of the circuit tomorrow?
Yes, this may help me to make a better support for these board.

Send me them to hxc2001 at hxc2001.com.

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Mon May 13, 2019 12:26 pm

I've sent you the images Jeff. Thank you again.

For others searching or googling out there, the machines the goteks are being fitted to are a Toshiba T-Series T3400CT where the floppy drive is still working but my floppu disks are getting less reliable and soon another will be fitted to a Toshiba T1850C which needs a replacement hard disk. I have yet to order that one's gotek and firmware though.

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Sat May 18, 2019 5:27 pm

I just wanted to post an update to help others out there. I’ve discovered that 0 Ohm resistors RA, RB and RC directly correspond with jumpers JA, JB and JC on the 34 pin gotek drives. As such, RA can be removed to mean custom firmware isn’t required, though as above, if you don’t want to remove it then you don’t have to, you just need to use appropriate firmware which disables the select button. If you wish to fit the select button, you must remove RA, the button can be soldered to these contacts and you must use the regular firmware.

The same goes for RB which I have removed to fit a buzzer. I can confirm this works as expected.

I have fitted a 7 segment LED display for now but will shortly replace it with the oled display.

Lastly, I have fitted a bi-colour LED as there isn’t room for two separate LEDs. It is important you use common anode LEDs here as common cathode won’t work. The polarity is at least marked on the circuit board. In my case the shortest cathode was green and is the leg nearest the buttons. Red is nearest the USB port.
2D076E8A-29B6-4C83-9B41-31E1F490266A.jpeg
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I will update the thread with my completed unit once the displays arrive and I’m done.

mikeyp
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Re: Slimline gotek drive hardware configuration

Post by mikeyp » Tue May 21, 2019 8:17 pm

Hi Jeff

I've just swapped in the OLED display which as you can see works flawlessly, however it does cause an odd issue, once initialised the red error LED stays on constantly. The green access LED works as normal.
IMG_1900.jpg
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If I swap back in the 7 segment display, it works normally, off most of the time and lighting red when I press a button etc.
IMG_1901.jpg
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Is this a bug in the firmware or something the OLED is causing?

Thanks again

Michael

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