Author Topic: help with floppy adapter PCB  (Read 3262 times)

0 Members and 1 Guest are viewing this topic.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
help with floppy adapter PCB
« on: 15:34, 25 April 17 »
People,

Can anyone out there help me with my floppy adapter to get my old classic CPC up and running so that I can begin further developments/testing of expansions. I am tired of waiting to use my 6128 via the tape port as it takes a very long time to run diagnostic programs on the expansions and simple errors in them are slow to be found and corrected.

There is a wiki page detailing the CPC internal disc interface and an example cable adapter for the HxC, but cant for the life of me understand how they get it to work with the HxC as the shift in 6 cable lines dont match the standard floppy interface that is also described. I check the tracks (for shorts and found none) and pin connections and cant seem to locate where I am going wrong.

Attached is the PDF of the PCB. I have checked the cable connections are correct setup and connected and pin header setups correct and all i get is "disc missing" and no disc movements. You may note that the ODD pins are not all connected to the same line. This due to the fact that the AMSTRAD interface (and floppy hardware) has them all connected to ground anyway.

The FDSS is the Floppy Disk Side Select (left is via software, right is via hardware).
The FDRDY is the ready signal (left is fixed to ground, right is supplied by the drive).
The HWSS is the hardware side select (top is for side 0 while bottom is for side 1). This is used to replace the "flipping of discs" in drive A if using AMSDOS.

I initially had both motor on signals tied together and the same for DS0 and DS1, thinking that it would not have an affect This setup seemed to fail to get very far as I could get a catalog of a disc, but would failed to run any program. I used utopia |Dedit and found It failed at times to read past track 8 (why track 8 i dont know). I suspected that having both DS0 and DS1 tied together confused the drive as to which command it was directed to, hence the attached was created to remove this confusion.

rpalmer




Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #1 on: 16:30, 25 April 17 »
Hi,
    the cable drawing was done by me, but I'm not sure what your confusion is. The 6 pin shift is because pins 2,4 and 6 on the shuggart connector aren't required. This fits to the pinout you've attached. But I have a question about your adaper PCB: Are both connectors on the same side of the PCB or is one on the bottom? Because if they are both on the same side you are connecting all CPC signals in the wrong order.

Bryce.

Offline robcfg

  • Supporter
  • 6128 Plus
  • *
  • Posts: 2.225
  • Country: se
  • 8-Bit Technomancer
    • index.php?action=treasury
  • Liked: 989
  • Likes Given: 2245
Re: help with floppy adapter PCB
« Reply #2 on: 16:31, 25 April 17 »
By looking on the schematics at the wiki and your drawing, I think you have some mixed lines.


 [ Invalid Attachment ]

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #3 on: 00:21, 26 April 17 »
Bryce, The pin header for the cable sockets are on the same side (see attached photo for how it is connected). I checked the cables to ensure that Pin 1 is connected to the bottom row of each pin header

Robcfg, I will give that configuration a try.

When I saw the CPC internal interface pinouts, I noted:

Pin 4 is /DRV1 (Drive select 1)
Pin 6 is NC (no connection)
Pin 8 is /MED1 (Motor Enable Drive 1)

and on the PC floppy cable pins, it was

Pin 10 (/MED0 Motor Enable Drive 0)
Pin 12 (/DRV1 Drive select 1)
Pin 14 (/DRV0 Drive select 0)
Pin 16 (/MED1 Motor Enable Drive 1)

And so I assumed that these connect as follows:

CPC Pin 4 (/DRV1) to Pin 14 (/DRV0)
CPC Pin 8 (/MED1) to Pin 10 (/MED0)

That is to comply with the drive select and motor enable pins to access Drive 0, so by shifting the cable 1 pin left it would mean the cable would connect as follows:

CPC Pin 4 (/DRV1) to Pin 10 (/MED0)
CPC Pin 6 NC to Pin 12 (/DRV1)
CPC Pin 8 (/MED1) to Pin 14 (/DRV0)

 Hence my confusion about shifting the cable by 1 pin header as shown by the cpcwiki diagrams as that would not connect the correct cable lines to their functions.

rpalmer

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #4 on: 02:05, 26 April 17 »
@rpalmer


Hi Ray


I have made up the internal 3.5" adapter cable (Bryce) for my old 6128 and it worked perfectly (NO Mods).


A bit out of left field :- why not use the HXC or an other drive  as an external drive as drive B (1)
you just have to make a 34 pin cable Pins 1 to 1 34 to 34 with appropriate connectors ?


Good luck        Ray
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #5 on: 13:35, 26 April 17 »
Hi audronic,

Did you have to change the floppy drive itself to supply a ready signal?
Did you install ParaDOS or remain with AMSDOS?
If AMSDOS then floppies only get to use one side, which is limiting the total space available, unless you had some way of selecting which side to work with.

Ray


Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #6 on: 14:49, 26 April 17 »
I assume you've modified the PC floppy drive to be DS0? Otherwise it thinks it's drive B:

Bryce.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #7 on: 16:05, 26 April 17 »
Bryce,

I modified the PCB so that CPC Pins 4 and 6 connect to Pins 10 and 12 and CPC Pin 8 to Pin 16. This leaves Pin 14 with no connection. This is as per the cable.

Robcfg highlighted pin 14 in yellow and I assume that this not connected at all. If this is wrong then I can patch this as well to ground to correlate with the info from robcfg. By doing this it will of course not match the cable from bryce as there it mentions no pins being joined. :'(
The drive is configurable and set to Drive 0, yet I still have no luck. I also tried setting it to Drive 1 and it sill does not work..... very confusing as to why the adapter fails :-[ .

If wondering why I chose this path, is because my first attempt via a modified cable failed miserably and the previous picture shows a new 26-way cable replacing the original.

Rpalmer

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #8 on: 18:01, 26 April 17 »
Why don't you just make the cable as I have shown in the Wiki? This is a known good configuration (I and others have built and used this design many times), so if it doesn't work then you know the problem lies with the drive.

Bryce.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #9 on: 23:27, 26 April 17 »
bryce,

I had only tested with patched PCB with one floppy drive and have more to try, so will give them a go.

rpalmer

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #10 on: 01:04, 27 April 17 »
Hi audronic,

1)  Did you have to change the floppy drive itself to supply a ready signal?

2) Did you install ParaDOS or remain with AMSDOS?

3) If AMSDOS then floppies only get to use one side, which is limiting the total space available, unless you had some way of selecting which side to work with.
Ray

Hi Ray P
1) Yes i used a common floppy drive a Sony MPF920.

and cut a track and added a wire link to Pin 34.


2) I have installed Parados 1.2 which i modified to default to A 40 Single sided and B single sided (used with the Sony MPF920)
If i need 80 track i can configure Parados for what ever is required.



3) Parados over comes the limitation


Good luck   Ray W


« Last Edit: 01:15, 27 April 17 by Audronic »
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #11 on: 01:19, 27 April 17 »
audronic,

So you in essence changed the interface on the drive rather than changed the cable to make it work. Which means you hard wired the /RDY line to ground on the floppy drive. Which track did you cut?

I have a SONY MFP902-1 and assume this is the same one you used for your internal 3.5 disk drive.

My aim with the PCB was to avoid making physical changes to the floppy drive, since one wrong modification will likely wreck it and getting a new drive is very hard as most computer suppliers no longer stock floppies.

rpalmer

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #12 on: 01:21, 27 April 17 »
sorry my mistake I see from the picture the /RDY line is not wired to ground

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #13 on: 01:30, 27 April 17 »
@rpalmer


Hi Ray P


Have a look near pin 34 and you will see that the trace is cut i forgot to include that in the Photo.
and Ooops i forgot the drive as incomes is wired for Drive 1 (one)


In the photo there is JC31 a ZERO ohms resistor that sets the drive ID Remove this and put a short on JC30 and the drive will become Drive 0 (A)


Ray W
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #14 on: 01:57, 27 April 17 »
audronic,

Thanks for the info, but my SONY floppy drive is not the same as that in the picture so its moot point about changing anything on it.

Rpalmer

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #15 on: 02:18, 27 April 17 »
@rpalmer


What is the chipset on the floppy drive


Ray W
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #16 on: 02:25, 27 April 17 »
@rpalmer


Hi Ray P


More sony stuff


Ray W
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #17 on: 10:19, 27 April 17 »
audronic,

So you in essence changed the interface on the drive rather than changed the cable to make it work. Which means you hard wired the /RDY line to ground on the floppy drive. Which track did you cut?

I have a SONY MFP902-1 and assume this is the same one you used for your internal 3.5 disk drive.

My aim with the PCB was to avoid making physical changes to the floppy drive, since one wrong modification will likely wreck it and getting a new drive is very hard as most computer suppliers no longer stock floppies.

rpalmer

It doesn't look like you have changed the drive to DS0. SEL0/1 (JC30/31) is still in its original position.

Bryce.

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #18 on: 12:34, 27 April 17 »
@Bryce


The photos were to help Ray P to see if he had that chip set in his Sony 920 Drive.


But they work well i have used both chip sets with my 6128.


Ray
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #19 on: 13:59, 27 April 17 »
@Bryce


The photos were to help Ray P to see if he had that chip set in his Sony 920 Drive.


But they work well i have used both chip sets with my 6128.


Ray

That doesn't answer the question: Have you moved the ~0R jumper on JC30/31? Or is it still in the position seen in that photo?

Bryce.

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #20 on: 01:22, 28 April 17 »
@Bryce


I am a bit confused ?
Which Photo Please ?


I have used these drives as Drive A with the link connected as per photo " Sony MPF920-z-121-hires (kipper)" ?
and i have changed the drive assignment link for Drive B.?


The Photo AMIGA-Sony MPF920E CXA48061Q Chipset-- WORKS is shown as Drive A ?
The Photo Amstrad Sony MPF920-03 is shown as Drive B as Indicated by the Pointer ?


What is your Point ?


Ray
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline Bryce

  • The Hardware Guy.
  • Supporter
  • 6128 Plus
  • *
  • Posts: 11.041
  • Country: wf
  • It's not broken, it just hasn't been fixed yet.
    • index.php?action=treasury
  • Liked: 3914
  • Likes Given: 407
Re: help with floppy adapter PCB
« Reply #21 on: 10:17, 28 April 17 »
@Bryce


I am a bit confused ?
Which Photo Please ?


I have used these drives as Drive A with the link connected as per photo " Sony MPF920-z-121-hires (kipper)" ?
and i have changed the drive assignment link for Drive B.?


The Photo AMIGA-Sony MPF920E CXA48061Q Chipset-- WORKS is shown as Drive A ?
The Photo Amstrad Sony MPF920-03 is shown as Drive B as Indicated by the Pointer ?


What is your Point ?


Ray

In this photo here. JC30/31 (Marked in red) are incorrect. To properly work as drive A: the jumper should be removed from JC31 and soldered across JC30. Otherwise the drive is only reacting to the SEL1 signal, not SEL0.

Bryce.


Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #22 on: 10:49, 28 April 17 »
@Bryce


Thanks


Ray
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline rpalmer

  • 6128 Plus
  • ******
  • Posts: 547
  • Country: au
  • Liked: 362
  • Likes Given: 18
Re: help with floppy adapter PCB
« Reply #23 on: 15:46, 29 April 17 »
hello people,

Well I managed to get something working, but it was not a complete success.

The video I uploaded to youtube (
https://youtu.be/ZL0do-DBHhI) shows where I am at (sorry about the quality as I was holding the camera and trying to operate everything with one hand).

In the video, I can get a catalog of a disc, but when I run a program the drive seems to be "locked" with the motor left on or something. I suspect and most likely need to make further changes to the PCB (this is the 4th iteration).

I must stress that the PCB is where I want to have all interface issues dealt with rather than 'modding" a floppy drive to suit as information on the old floppy drives (mid 1990's types) I have is very scarce.  I also still need these disc drives to still work in my very old PCs. The other reason being that if the PCB does everything required then anybody can upgrade their classic 6128 without the need for use of a soldering iron.

rpalmer

Offline Audronic

  • 6128 Plus
  • ******
  • Posts: 1.265
  • Country: au
  • I know RST3 . I now know a little More.
  • Liked: 296
  • Likes Given: 630
Re: help with floppy adapter PCB
« Reply #24 on: 02:14, 30 April 17 »
@rpalmer


Hi Ray P
If you ever come to Victoria I have 1 Sony 920 waiting for you already modified for the princely sum of $ 00.00 (No returns accepted)
I looked at the Video and was wondering if the 3.5" disk was faulty as the light flashes were consistent for part of the video and then changed the pattern ???

PS Are you using a 720K disk ?

Good luck on the project.


Ray W
« Last Edit: 02:16, 30 April 17 by Audronic »
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.