This was an ebay purchase and the following image was included in the listing. This card does not appear to have been included on pickup. I assumed it was the controller card but it's not. Any ideas what this is?

jarcher1701 wrote on 2023-10-15, 21:45:

I assumed it was the controller card but it's not. Any ideas what this is?

This is an MFM/RLL HDD (possibly ESDI), looks to be a more modern 3.5" HH size. It's upside down and you are looking at the PCB (unless this particular model has PCB on the top, some did).

As for your floppy drive issue, the card on your photo is a HDD controller judging by the 20-pin connectors. Is there a floppy drive header on it, and is the floppy drive connected to that? And not to HDD cable?

Good point Deunan ! There is no floppy controller on that Wd1002s it is a 8bit MFM only adapter. I thought the floppy controller was on the motherboard of PC1640, near the ram iirc

Thank you both for replying! Much appreciated.

I'd assumed the controller card had a floppy and HDD connection but it appears not (although, confusingly, the connector did fit the floppy drive).

I've completely removed the controller card. Now I'm just using the data cable coming from the mainboard labelled 'disk drive' along with the standard Molex power connector to connect up the floppy drive (please see photo). The data cable seems to connect in both orientations. I know the red data line needs to be connected to pin 1 but it's not clear which orientation is correct. In one orientation, the yellow floppy light comes on and stays on. In the other, the floppy light never comes on.

With either orientation, the error message displays. With nothing connected to the floppy drive, the error still displays.

There was one occasion - and I'm not sure what caused it - where this drive error message didn't display and it said something about the battery. I haven't been able to replicate that.

My next step was going to be to remove the main board and give all socketed chips a clean and look for any obvious issues. As you can see, there's some light rusting on the shield.

Do you have any further advice?

jarcher1701 wrote on 2023-10-16, 06:33:

I've completely removed the controller card. Now I'm just using the data cable coming from the mainboard labelled 'disk drive' along with the standard Molex power connector to connect up the floppy drive (please see photo). The data cable seems to connect in both orientations. I know the red data line needs to be connected to pin 1 but it's not clear which orientation is correct. In one orientation, the yellow floppy light comes on and stays on. In the other, the floppy light never comes on.

Floppy drive LED should not come on (and stay on) right as the power is applied. If that happens the flat cable is plugged in backwards, needs to be rotated. There should be a notch but many cables didn't have it, some drives didn't either, and some even had it on the wrong side (hence why cables without the notch exist).

If it doesn't work plugged in the other way it might be due to some misconfiguration of the BIOS settings perhaps? Which is possible if the battery went flat or dead (in which case BTW you want to make sure it's not leaking electrolyte and damaging the mobo). I've never had an Amstrad machine so frankly I do not know what and where to check or set to get the floppy configured properly...

EDIT: MFM HDD 34-pin connector is "compatible" with floppy drive one, that is it fits - it's normal. But the signals are different and it will not work properly.

Deunan wrote on 2023-10-16, 10:38:

Floppy drive LED should not come on (and stay on) right as the power is applied. If that happens the flat cable is plugged in backwards, needs to be rotated. There should be a notch but many cables didn't have it, some drives didn't either, and some even had it on the wrong side (hence why cables without the notch exist).

If it doesn't work plugged in the other way it might be due to some misconfiguration of the BIOS settings perhaps? Which is possible if the battery went flat or dead (in which case BTW you want to make sure it's not leaking electrolyte and damaging the mobo). I've never had an Amstrad machine so frankly I do not know what and where to check or set to get the floppy configured properly...

EDIT: MFM HDD 34-pin connector is "compatible" with floppy drive one, that is it fits - it's normal. But the signals are different and it will not work properly.

Thank you for confirming regarding the floppy data cable. I wondered whether a continuous 'on light' on the floppy meant it was the wrong way round. 😀

Hopefully someone can assist with the error code which is still displaying despite the cables now being the correct orientation.

Hello! Thanks for the email. Thought I'd reply here in case it's useful to anyone in future...

It's been a few years since I was working on the PC1512, but I do remember this error. I think Deunan above might be on to something - do you have any CMOS batteries installed? There's a AA battery holder built into the case, think? I think not having the batteries installed can cause it to complain. IIRC there isn't the usual "press ESC for BIOS setup" but you need to boot from a floppy and run a utility to set these values, which isn't very useful if the drive has been changed...

Apologies if that's a bit vague, I'll add more if I remember but like I say, it's been a few years!

ctrlaltrees wrote on 2023-10-16, 12:00:

Hello! Thanks for the email. Thought I'd reply here in case it's useful to anyone in future...

It's been a few years since I was working on the PC1512, but I do remember this error. I think Deunan above might be on to something - do you have any CMOS batteries installed? There's a AA battery holder built into the case, think? I think not having the batteries installed can cause it to complain. IIRC there isn't the usual "press ESC for BIOS setup" but you need to boot from a floppy and run a utility to set these values, which isn't very useful if the drive has been changed...

Apologies if that's a bit vague, I'll add more if I remember but like I say, it's been a few years!

Thank you for responding to my plea for assistance! 😀

I tried adding batteries but unfortunately the error message persists. I will need to check however that power from the batteries is reaching the board. There could perhaps be a break in the wires.

The previous owner removed the hard disk that was installed so I wonder if that is the issue. Could the bios be looking for the hard disk - hence the error? But if there are no batteries, wouldn't that clear the bios automatically?

Thanks again for your help.

Another thought...

The previous owner removed the hard drive from the system. There is a jumper setting on the 5.25 inch drive. It's currently set to 0 (0,1,2,3). Although zero seems logical, should it be 1 - or something else?

I took apart the machine and gave everything a clean. I re-seated all the socketed chips. The error message still appears. 🙁

Does a working floppy drive need to installed and working to get to some sort of system prompt on the Amstrad PC1640? I've tried connecting and disconnecting the original Amstrad 5.25 inch drive and the error message appears regardless. Or could the error message suggest the FDC chip - or surrounding circuity - is faulty?

I've checked the data lines of the floppy cable to the motherboard pins and all are showing continuity.

I've recently picked up a PC1640 and was getting the same error on my screen.
To get past that error, you must have a working 360k floppy drive connected and the setting should be set to: 0

It might be an idea to test the floppy drive in another computer, you may need to change the jumper setting to 1 depending what other floppy drives you have installed.
Also if you haven't already, make sure the drive is getting the correct voltages via the molex.

Once you have a working drive, it should boot straight into DOS (with a boot disk).

I'm currently trying to work out what to do for a storage drive, as a single 360k drive is pretty useless....
I do have the MFM HDD, but it seems to be dead and doesn't sound good at all.

I wanted to return to this post with the solution to my non-working Amstrad PC1640.

It turned out to a dodgy capacitor (C124) that resulted in a blown resistor (R181) which prevented IC110 from being powered by the 5V line. This resulted in an interrupt error which meant the start-up checks were failing - hence the error message. The drive was not being initialised. The drive was working absolutely fine and the PC now boots.

If anyone's interested, you can read about it over at the Vintage Computer Forums.

https://forum.vcfed.org/index.php?threads/ams … -drive.1245278/