HXC Gotek not working on 464 DDI interface

[Bignumbas]

I have a 464 with a DDI interface that will not recognise an HXC Gotek usb drive no matter how I slice and dice it.
I have done the 5v mod on the interface board and cut wires to 34 pin connector as per Bryce's instructions.
3.5" floppy works fine.
I have installed Audronics modified Paradosv2m Rom but I get the same problem with the original AMSDOS rom.
I came across this description which is my problem it seems: http://torlus.com/floppy/forum/viewtopic.php?f=8&t=1658.
I tried shorting pin 34 on the Gotek to ground but it does not do anything.
Anybody got any clues?
I have just made some disks with CPCdiskXP and found that I had to write the disk using head 2 otherwise they could not be read in the floppy attached to the DDI, could this be the problem with the Gotek, Head select is wrong?
I tried shorting 31-32, still not working.
How to change that?

[Bryce]

Is the DDI-1 initialising: ie: Does the command |A work or does it give an error?
Is the flat cable fitted the right way around to the HxC?
Is the HxC reacting at all, or does any LED flash when you do a CAT?
Have you tested the DDI-1 with a real floppy drive?

Bryce.

[Bignumbas]

2 x 3.5" floppies work as a and b, I can run CPM\Amsdos and access both drives
The only problem is the hxc gotek usb is not recognised as having a disk
|A  or |B goes to no disk, retry.
The gotek initialises and goes to 000 and I can change disks in the slots but cannot access them.
I have also changed the gotek for another and it works fine in a 6128 internal or external.
??
I seem to remember back in '85 running CPM 3 on a 464 with  a dk'tronics 64kb expansion.
Now it says I cannot do that.
Is this the Mandela effect in action?

[Audronic]

@Bignumbas


Is this of any help ?


http://torlus.com/floppy/forum/viewtopic.php?f=8&t=644&p=4426&hilit=amstrad+amstrad+464#p4426


Ray

[Bignumbas]

No, that's about the amstrad 3" floppy to 3.5" adapter.
Technically if the 3.5" drives work, as they do, the gotek should too.

[Bignumbas]

Connected up a 3" amstrad floppy and that works fine.
Discovered that the cable header has had socket connector #12 removed so you cannot use it for anything but drive A.
I notice that the second cable header has 2,4,6,10,12 removed, so no power and no drive A allowed on that header only drive B.
I changeg the settings of the Hxc config file and can actually get a disk read when I set it for Shugart but I only get disk space no file listing.
I suspect the problem lies in the Hxc firmware unless its one of the chips in the DD1.
The FDC or one of the 74LS38 ?
It is the same circuit used as the 6128, yes?
It works in the 6128???

[Audronic]

@Bignumbas


After the chat on the Phone i would start looking at IC106 and IC108 (74LS38) In the Interface.
They also suggest that you can use 7400"s (NOT Open collector).


Ray

[Bignumbas]

Well I now know exactly what the problem is.If I config parados to use Side 1 on an Amstrad 3" CF2 floppy drive I should see the opposite side of the disk to what I normally see. Yes?
On my system I still see Side 0, no change.
This is what I see as my problem.
If I connect a 3.5" drive to the 6128 the discs I made for the DDI-1 cannot be read until  I change the side to Side 1 with Parados config.
I can then read them as Side1.
SO I have a DDI-1 that is permanently stuck on Side 1. My logic probe says pin 32 is  low (green led)
I have replaced IC106 (74LS38) which controls Ready and Side.
I have now socketed the FDC 765 chip and changed it for a known working one from the 6128.
Anybody got suggestions as to which chip is the problem child?
OR, do I just work my way through them like I did with the dead 6128 I fixed?

[Audronic]

@Bignumbas


Cd101 ( Connector on DDI )

Pin

1   =   34      /Ready
3   =   32      /Side 1 select
5   =   30      /Read Data

etc

31   =   04
33   =   02


Static Test (After Power  up or Reset)

Whats On

First:- (Drive Select)

Pin 08    of IC106      (LO)
Pin 06   of IC106      (HI)

Then :- Side Select

Pin 11    of IC106       (HI) ?
Pin 12-13 of IC106      (LO) ?

Just some Thoughts

Ray

[Audronic]

@Bignumbas


As an after thought what if you put 7400"s in IC106 and IC108 and see what happens ?
It is possible that the DDI-1 is addressing the wrong drive select line ?


Ray

[Bignumbas]

I have already replaced them..
The problem starts on the output from the FDC765 controller chip. Pin 27 (side select) is permanently low)
I have replaced the 765 with a known working one.
It seems to be between the bios and the control of the 765 inputs.
I tested a 6128 and the state of pin 27 is high and I can access both sides of a 3.5" floppy using Parados
There is only a minor difference between the 6128 and the DDI-1 cct.
I an no expert on floppy disk interfaces and there is no cct of the innards of the 765 that I can find.

[Audronic]

@Bignumbas

If pin 37 is LO on the UPD765 what is the logic level on Pin 11 of IC106 (74LS38)
it should be HI (Selecting Head 0) ?.

? Did you say that a 3.5" drive worked on this cable ?

Love the Avatar.

Ray

[Bignumbas]

IC106 pin 11 is low.
If I plug a 3.5" drive into the 6128 everything works as it should, I can select sides with Parados.
If I do the same on the 464 with DDI-1 it is stuck on side 2 and cannot change to side 1.
I cannot change sides with Parados and thus the Gotek does not work because it is stuck on side 2 and it is supposed to be side 1.
The disk images are one sided. I guess if I had a 2 sided disk image I could access side 2.
Is there such an image?
Please send a copy if you have one.

[Audronic]

@Bignumbas


Ok . can you put a 3.5" drive on the end of the DDI-1 and see what happens when you make a Single Sided Disk with some files on it,
using CPCdiskXP (40TK S/Sided).


Ray

[Bignumbas]

I have a temporary fix. 


If I cut pin 32 on the rear of the 34 pin male connecter the Gotek works.
Now if I put a switch on this cut I can choose sides.
I can always solder it back together when I figure this out
Now the HXC Gotek is the same as an Amstrad floppy drive, one sided.
At least it works now.
Desperate times call for desperate measures!
Have you tried an HXC Gotek on a DDI-1 Audronic?
Maybe this is an Alan Sugar protection thing.

[Audronic]

[quote author=Bignumbas link=topic=13040.msg141723#msg141723 date=1487575582]
I have a temporary fix. 

Have you tried an HXC Gotek on a DDI-1 Audronic?

No I don't have a HXC Gotek , I have a normal HXC That i could play with, it's packed away at the moment.
Off to Tasmania for 4 Days, Tomorrow.
Talk to you later     Ray