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
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.
By looking on the schematics at the wiki and your drawing, I think you have some mixed lines.
[attach=2]
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
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
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
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
I assume you've modified the PC floppy drive to be DS0? Otherwise it thinks it's drive B:
Bryce.
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
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.
bryce,
I had only tested with patched PCB with one floppy drive and have more to try, so will give them a go.
rpalmer
Quote from: rpalmer on 11:35, 26 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
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
sorry my mistake I see from the picture the /RDY line is not wired to ground
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
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
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
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
What is the chipset on the floppy drive
Ray W
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
Hi Ray P
More sony stuff
Ray W
Quote from: rpalmer on 23:19, 26 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.
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
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
Quote from: Audronic on 10:34, 27 April 17
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
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.
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
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
Quote from: Audronic on 23:22, 27 April 17
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
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.
@Bryce (http://www.cpcwiki.eu/forum/index.php?action=profile;u=225)
Thanks
Ray
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 (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
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
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
Audronic,
I live on the other side of the country so the offer would be expensive for me to collect...LOL
Yes I am using 720 K discs. The continuous light seems to both me much as i would have thought that it come on when drive is selected and motor is enabled.
Ray
@rpalmer (http://www.cpcwiki.eu/forum/index.php?action=profile;u=379)
Hi Ray P
do you have Parados fitted to your machine ?
I often use that in the Verify mode to look at Problem disks etc.
Ray W
audronic,
I do have the ability to create a ParaDOS rom and can replace the internal ROM, but chose not to do so as I want to be able to get the replacement drive to work on the basic unmodified CPC.
I may plan to change to ParaDOS later, but for now I am happy with plain AMSDOS.
rpalmer
Some sad news about the my cpc.
I had just fried the Z80 CPU (accidentally touched GND and 5V using multimeter)... bugger :'(
I have order some DUIP40 8MHz Z80 and expect to get up and going again soon.
rpalmer
While I wait for the delivery of my replacement Z80's.
I have re-visited the web site (http://www.cpcwiki.eu/index.php/DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator (http://www.cpcwiki.eu/index.php/DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator)) detailing how to replace the internal floppy drive with the HxC/PC Floppy and find there appears to be an inconsistency with the cable shown.
The inconsistency is with the cable adapter mentions that the 6 rows of the 26-Way cable from the red line are shift by 1 pair of pins in the PC interface floppy cable.
I checked what the shift in the cable means for a PC floppy interface and find the following occurs:
CPC Pin 2 (/DRV1) connects to Pin 10 /MED0 on the PC floppy interface
CPC Pin 4 (NC) connects to Pin 12 /DRV1 on the PC floppy interface
CPC Pin 6 (/MED1) connects to Pin 16 /MED0 on the PC floppy interface
Pin 14 (/DRV0) is left unconnected on the PC Floppy interface as shown.
What this means is that both /DRV0 and /DRV1 on the PC floppy interface are effectively not driven (in fact they are 'floating'), so how can this interface adapter work if both drive selects are not used? I can only assume that Pin 14 on the PC interface is tied "low", but this is not specified anywhere on the site. Robcfg highlights in yellow what appears to indicate that it is, but the connection would be very hard to join even for those game to try.
Meanwhile I read further down and find that only Pins 1 to 2 of the CPC cable should be moved 1 pair of pins to align with the /IND signal and ground lines with the PC floppy interface while the other signals lines are mapped 1 to 1 with the PC interface. This means that pin 26 of the CPC floppy cable matches with Pin 34 of the interface and so on going backwards up to cable. This mapping of the cable matches more closely how the connection should be done for a 3.5 inch floppy and leaves only the Ready/Side select signal to be modified as required for a standard PC floppy drive.
Have I missed something from the web-site?
rpalmer
Quote from: rpalmer on 13:41, 04 May 17
While I wait for the delivery of my replacement Z80's.
I have re-visited the web site (http://www.cpcwiki.eu/index.php/DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator (http://www.cpcwiki.eu/index.php/DIY:Floppy_Drives#Multi-Adaptor_Cable_for_External_Floppies_.2F_HxC_emulator)) detailing how to replace the internal floppy drive with the HxC/PC Floppy and find there appears to be an inconsistency with the cable shown.
The inconsistency is with the cable adapter mentions that the 6 rows of the 26-Way cable from the red line are shift by 1 pair of pins in the PC interface floppy cable.
I checked what the shift in the cable means for a PC floppy interface and find the following occurs:
CPC Pin 2 (/DRV1) connects to Pin 10 /MED0 on the PC floppy interface
CPC Pin 4 (NC) connects to Pin 12 /DRV1 on the PC floppy interface
CPC Pin 6 (/MED1) connects to Pin 16 /MED0 on the PC floppy interface
Pin 14 (/DRV0) is left unconnected on the PC Floppy interface as shown.
How do you come to this conclusion? If I skip the first 6 cavities, then pin 2 of the CPC (Index) goes to pin 8 (Index) of the PC floppy connector. Pin 4 (DSEL0) goes to PC Pin 10 (DS0) and CPC Pin 6 (NC) goes to PC Pin 12 (DS1). Pin 14 of a PC floppy drive (the one that gets skipped in the middle of the flat cable) is DS2.
Just a wild guess here, but as well as mixing the pin numbers, are you possibly looking at the pinout of a shuggart controller instead of a PC floppy drive pinout?
Bryce.
Edit: For reference, here is the pinout of a PC floppy drive vs. Shuggart controller pinout:
http://marcosim.homepc.it:8080/sites/Marco/FloppyArduino/index.php/downloads/Floppy_Pinout.pdf (http://marcosim.homepc.it:8080/sites/Marco/FloppyArduino/index.php/downloads/Floppy_Pinout.pdf)
Edit 2: If anyone is wondering why I connect CPC Pin4 although it's not connected in the CPC, this was to allow certain ABBA switch methods to work with the cable.
Ok, I've just spotted that someone (not me) added a section with "Signal assignment on connectors" and has wrongly listed the Shuggart CONTROLLER pinout instead of the Floppy disk shuggart pinout. That could be the reason for some of the confusion.
Virtual slapping to whoever did that, I'll change it now....
Bryce.
Edit: Pinout corrected on Wiki page. Maybe now it makes more sense?
Bryce,
At the web side the connections in "Internal floppy connector CD201 to standard floppy connector 34pin" section showed that only 2 lines are moved and it is this which is inconsistent with moving 6 lines in the cable layout in the section "Adaptor Cable for Internal Floppies / HxC emulator".
The section "Standard floppy connector 34pin" is now currently incorrect as it previously it was correct.
rpalmer
The one i use is the "Current" for all the old machines i work on.
Good luck
Ray W
Quote from: rpalmer on 21:59, 04 May 17
Bryce,
At the web side the connections in "Internal floppy connector CD201 to standard floppy connector 34pin" section showed that only 2 lines are moved and it is this which is inconsistent with moving 6 lines in the cable layout in the section "Adaptor Cable for Internal Floppies / HxC emulator".
The section "Standard floppy connector 34pin" is now currently incorrect as it previously it was correct.
rpalmer
Sorry, but you are wrong. The google image you have linked to is NOT the pinout of a floppy drive, it's the pinout of a floppy drive
controller which is different. Unfortunately this mistake is repeated all over the internet which is extrememly annoying. I deliberately included this link earlier: http://marcosim.homepc.it:8080/sites/Marco/FloppyArduino/index.php/downloads/Floppy_Pinout.pdf (http://marcosim.homepc.it:8080/sites/Marco/FloppyArduino/index.php/downloads/Floppy_Pinout.pdf) because it shows both the controller and floppy pinouts so that the differences can be seen.
Equally, whoever made these tables in the CPCWiki (someone called Petermeier according to the Wiki records), didn't even manage to copy the CD201 pinout correctly from the schematics. If you look at the attachment below you will see that DSEL1 (marked in green) definitely doesn't go to CD201, it only goes to the 34way connector (as it should be). Only DSEL0 (red) goes to the CD201. And pin 8 is not MED1 because the 765 doesn't have MED signals. The CPC MotorON (which is what pin 8 really is) is derived externally from IC212 and enables the motor of all drives at the same time.
The easiest way to resolve the inconsistencies would be to remove all those tables from Peter completely as they are full of errors. Or someone needs to take the time to go through them all and correct them.
Eitherway, the two cables diagrams that I made, both the external multicable and the internal 26 to 34way cable have been built many many times and are working fine for anyone who has one, so they are definitely correct.
Bryce.
ah the waters part and the path is made clear...thanks bryce
Quote from: rpalmer on 09:24, 05 May 17
ah the waters part and the path is made clear...thanks bryce
Call me Moses :D
Bryce.
Edit: For those who are interested. The pinout difference between the controller and the floppy drive is what makes the famous cable twist seen in PC floppy cables possible. By twisting the cable you are swapping the positions of /DRV1 + /MED1 with /DRV0 + /MED0, hence making the drive with the twist to A: and without twist B:.
no for good news...
I just installed my new Z80 cpu and my beloved CPC is alive and kicking goals....yeah... ;D
The new cpu are the 8MHz variety...oh do i wish i could push it to their specified 8Mhz speed.... that would make the CPC run like usain bolt LOL.
rpalmer
I have just etched and tried an interface with the same pins moved as detailed by bryce, yet I still cannot get the drive to work as expected.
The youtube video https://youtu.be/XochiSlCAtU (https://youtu.be/XochiSlCAtU) shows that the drive spins to get the disc moving after the command "CAT" is issued, but then there is only a "whinny" sound. The command does not return.
If i remove the disc after the whinny sound starts I get "disc missing" error.
The floppy drive is a TEAC FD-235F and has pin header to set the drive as DS0/DS1 (I chose DS0). It also has a DC/RY select ... guess what I chose RY for disc ready.
I also tried an Alps DF-354H modified to be DS0 and not DS1... it too failed to work.. although i cant tell if the motor was spinning as the cover blocks seing in motion.
Before anyone says oh you must have a short somewhere to get the drive to make that whinny sound.....
I check the interface for shorts and found none.
I checked the cables and found none there as well.
I checked if the cables to see if they were not aligned when inserted ... they were both properly inserted.
I checked if the pins from the CPC interface went to the correct pins on the floppy drive...guess what they were correctly linked (pin 26 to pin 34, pin 24 to pin 32, etc)
Attached is the PCB photos and eagle layout in PDF.
WHAT HAVE I DONE WRONG?????
I would like to note one of my previous attempts seemed to work, but resulted in the drive making a similar whinny noise and on that occasion the cat command did return. The sound did not stop though.
rpalmer
Are you sure the power part is correctly wired?
I mean, it seems that on your pcb you removed the 12v, but if I remember right the power pins are really swapped so you are feeding 5v to the wrong pin.
Sent from my iPhone using Tapatalk
robcfg,
If the 12V were fed to the floppy drive then it would not have worked at all as I had disconnected the 12V supply with the monitor (it was not needed anymore) and the drive would have no power at all.
rpalmer
What OS are you using? AMSDOS or ParaDOS? If the disk is starting to spin but nothing else happens, then your problem seems to be with the ready signal.
Bryce.
bryce,
I am using AMSDOS. I can program an EPROM with paraDOS, but I understand that should not be a problem.
Can't be the ready signal as the TEAC drive provides it. The Alps drive does not but the jumper was tied to ground and so the CPC was seing the drive as 'always' ready.
Rpalmer
Are you sure the FDC circuitry is ok? Have you any 3in drive that works on this CPC?
Bryce.
Bryce,
Sadly I don't have a spare one, which makes this effort so much more harder to get working.
One of the previous PCBs seemed to work when I was able to get disk catalogs, but I was unable to run anything cleanly. It maybe the discs have corrupted sectors, but again I cant tell easily if the media is kaput or the copy I had the corrupted sectors when copied back. My copy was from original discs of CP/M+ which was used for testing. I was also testing a copy of Disc Master which started up but gave disc errors.
rpalmer
The reason I ask is because it is very easy to damage the two output buffers on the FDC if you wrongly connect a drive. I suspect that you have damaged the FDC circuitry and your adapter / disk drives are actually fine.
Bryce.
I have a spare FDC chip I could try.
I don't think there is an issue with your FDC, my external drive is playing up and has symptoms like yours but the internal drive is just fine. Before you start desoldering chips can you get an external cable and connect it to the back of the machine, jumper the ready signal and it should work as drive B. I would try that before desoldering anything, if that doesn't work then maybe there is another issue somewhere.
tjohnson,
My FDC was socketed and I can replace it when i need to... thank heavens for forward thinking almost 15 years ago.. ;D
rpalmer
Quote from: rpalmer on 13:06, 16 May 17
tjohnson,
My FDC was socketed and I can replace it when i need to... thank heavens for forward thinking almost 15 years ago.. ;D
rpalmer
That's good. Do you have an old school floppy cable with the edge connector? Definitely think it's worth trying that, i have a feeling it might have something to do with the adapter.
Sent from my E5823 using Tapatalk
I originally had an external 3.5 drive connected, but was used in my first attempt to replace the internal one when it dies 10+ years ago.
Alas the drive is all that is left as my many moves due to work has resulted in loosing the housing and setup.
I will have to make up a power adapter and cable to perform such a test.
rpalmer
Can you buy the right sort of cable in a local electronics store where you are?
i would have to search through all of my cables to locate the one to connect the drive, but i am sure i have it somewhere.