Amstrad PC1640 - Faulty Floppy Disk Controller or Disk Drive

[Malc]

Do you need an original, or are there adaptors out there for using a modern keyboard?

I don't know of any adapters, Original will do but i'm in no hurry, Will see what turns up, Had this for nigh on 20 years and this is the first time i've powered it up.

 

[Malc]

It would be interesting to see what Rudd's Diagnostic ROM makes of the situation.

Out of interest I just ran RDR on my Amstrad PC1640, Works fine Ignore the 'Keyboard Fail' it's because i don't have the Keyboard for it.

 

[jarcher1701]

Out of interest I just ran RDR on my Amstrad PC1640, Works fine Ignore the 'Keyboard Fail' it's because i don't have the Keyboard for it.
View attachment 1269158

It would be very interesting to run that on my machine once I have it verified up and running (still waiting for the system disks).

Did you burn it to EPROM and replace the Amstrad ROM? Is that the only way of running it?

 

[modem7]

Did you burn it to EPROM and replace the Amstrad ROM? Is that the only way of running it?

Yes, that it the only way of running it.

 

[jarcher1701]

The Amstrad system disks arrived today. Some pics attached of it working. All seems okay.

Some minor issues:
-Disk is not always read when first inserted into drive. Reinserting seems to resolve this.
-Not visible in photos is a vertical band of a slightly darker image on the left side of the monitor (only visible with a white background)

I tried a 5.25 inch game I have - PGA Tour Golf. Although the disks were read and the directory could be viewed, the game didn't launch. The disk was accessed for a few seconds and then the disk light stayed on and nothing happened. Bad sectors or damaged disk perhaps? I don't know if the disks are working as I've never had a machine with a 5.25 inch drive before.

I do need to replace that cap I removed and clean the drive again.

 

[jarcher1701]

Hello all. Happy new year!

I've been investigating this PC a bit more. The Amstrad system disks all work absolutely fine and GEM seems to load and function fine as well. This has been confirmed via the original Amstrad floppies as well as via Gotek disk images (FlashFloppy).

However, trying to load games of this era - such as Prince of Persia, PGA Tour Golf, Double Dragon and even Planet X3 - either nothing happens on the screen (just a black screen or flashing cursor) or there's a garbled screen.

In Planet X3, selecting Monochrome Hercules or any of the CGA modes on start-up just results in a garbled screen - although the audio seems to work. Please see screenshot 1.

The display DIP switches are set as per the yellow highlights in the second screenshot. I have an MD monitor.

Thanks in advance!

 

[austfox]

I believe Prince of Persia was the first game I ever purchased for my PC back in the late 80's. I dug out the disks to test on the PC1640. Disks were in immaculate condition because they have been stored in an airtight plastic tub for the last 30+ years!

I thought I had a PC-MD monitor to test them on, but all mine are either PC-CD or PC-ECD. On my PC-CD monitor the jumpers were originally set to CDMono and I got the message along the lines of 'Graphics mode not available', but worked well when switching to CDColor:




I tried your settings for MDMono (off, off, on, off, off) but got a garbled screen, however the MDMono CGA compatible 40 column mode worked (on, off, off, on, on):

Edit: actually, looks like I read the table wrong... the CGA comp 40 column is part of the CD display, not the MD display. Did you try the MDText mode?

 

[jarcher1701]

Thank you for taking the time to test Prince of Persia @austfox.

As you suggested, I tried MDTEXT and it worked for Prince of Persia and Planet X3. Screenshots attached. Planet X3 looks high res and quite impressive in that mode.

So MDTEXT is meant to support the IBM 'Monochrome Display Adapter' MDA standard. That makes sense. A few games clearly support this. I tried Indianapolis 500 in this mode and I got an error - saying no CGA, EGA or VGA card was detected - which I suppose makes sense.

I'd be keen to try and get the MDMONO to work though - which is basically EGA but in shades of grey. This is what I had set before and games I would expect to work here didn't - such as Indy 500.

I'll have to do a bit more testing.

 

[austfox]

Just thought I'd point you to a YouTube channel that has a few videos on the Amstrad PC range and talks about the video modes:

PCRetroTech

 

[genesis8bit]

Hi,

MDTEXT is for MDA (no pixels, just characters) or Hercules (compatible with MDA but with a 720 × 348 pixel mode). So in MDTEXT you should be able to use any program capable of Hercules mode.

MDMONO should you let to use any CGA (4 greys) / EGA (16 greys) programs.

I only had a PC 1512 back in the days though, a PC 1640 with an ECD monitor would be wonderful, at least I can play with my PPC 640 and the PicoMEM (midi on a PC XT is so sweet).

 

[coolchilli]

Hi everyone -

I've just unboxed my PC1640 which I've had stored for about 30 years. Quite remarkably it started, complaining initially of the battery, then the hard drive - perhaps unsurprising after such a long time...

I've tried to boot to floppy disk (admittedly, unknown condition) - and this failed. Now I'm trying a GoTek with an IMG file of MS-DOS 3.20 which seems to be a version for Amstrad computers. In return I'm getting the error reported here "Error: Faulty Disk controller or Disk Drive".

I had to use an edge adapter to get my Gotek to fit the Amstrad cable, but I noticed there is a second Shugart connector on the cable (that appears to be glued? to the motherboard) - so I'm going to wire up an extension and see if I can get the Gotek to work this way.

I'll report back my progress in case other users have had similar trouble. But by the looks of things, I think the motherboard will need to come out and I'll need to go hunting for failed caps and resistors...

 

[modem7]

Hi everyone -

Hi. Welcome to these forums.

... complaining initially of the battery, ...

Which will be for the PC1640's real-time clock.

... then the hard drive - perhaps unsurprising after such a long time...

After 30 odd years, a possibility is 'gummed up' lubricant on the spindle. Do you hear/feel the platters turning ?

I've tried to boot to floppy disk (admittedly, unknown condition) - and this failed.

After 30 odd years, a possibility is deteriorated lubricant on the drive's head carriage rails - see [here]. It is a problem that is often reported. Certainly something to check out.

Now I'm trying a GoTek ...

In case you are unaware: Because the PC1640 uses a flat/untwisted floppy cable, you may need to change the drive-select jumpers on the GoTek.

 

[coolchilli]

thank you for the warm welcome @modem7 - it's good to be here. I'm finding forums like this invaluable for getting my collection of 8- and 16- bit computers back into service...

RE: Hard drive - yes, I hear the platters turning. If you know of any good DIY guides to repair the HDD, I'd be grateful - frankly, I'd written it off...

I'll cehck out the link on the FDD - thanks for this.

As for the GoTek - no, I was totally unaware of this! I'll look into the jumper settings, as with the original FDD connected, I get no such errors!

 

[modem7]

RE: Hard drive - yes, I hear the platters turning. If you know of any good DIY guides to repair the HDD, I'd be grateful - frankly, I'd written it off...

The hard drive controller is also 'in the equation'. (Yes, it is more likely that the HDD is the problem.)
In case of poor connection, reseat the controller in its ISA slot a few times.
In case of poor connection, reseat the connectors on the drive and cables.

Although you hear the spindle turning, there is a possibility that deteriorated (or partially solidified) spindle lubrication is resulting in the spindle not reaching full speed. We have had cases of people being in a similar situation to you, and their HDD 'comes good' after it has been left running for a while.

Deteriorated aluminium electrolytic capacitors in the HDD ? (They can dry out.)

All kinds of possibilities.

What is the make-mode of HDD controller and drive ?

As for the GoTek - no, I was totally unaware of this! I'll look into the jumper settings, as with the original FDD connected, I get no such errors!

The IBM PC family, and most clones, use a particular type of 'twisted' floppy cable, shown at [here]. Accordingly, the drive-select jumpers on both attached floppy drives are set to the second drive-select position.

The PC1640 is an example of a clone that uses an untwisted cable. I presume that the first drive (A) is set to the first drive-select position, and if a second is fitted, that one set to the second drive-select position.

 

[coolchilli]

thanks again @modem7 - i'll come back to the HDD later on the hope that with a few hours of spinning it might come back to life itself.

with the Gotek - the only guide to jumpers I can find is this: https://hxc2001.com/docs/gotek-floppy-emulator-hxc-firmware/pages/firmware-settings.html

I don't actually have any jumpers on the S0, S1, or M0 positions, and can't find any spares close to hand - so will order a pack and report back once they arrive and I've got this set to S1 (which I assume from the page above is the correct setting).

Will report back here so other users with similar difficulty have a reference point.

 

[modem7]

I don't actually have any jumpers on the S0, S1, or M0 positions, and can't find any spares close to hand - so will order a pack and report back once they arrive and I've got this set to S1 (which I assume from the page above is the correct setting).

The web page that you pointed to includes, "Generally for PC compatible machines the jumper to set is "S1". For Shugart compatible machines this is S0 or S1 for the second drive."

Notice the "Generally". Although the PC1640 is considered a PC compatible, no PC compatible is a 100% clone, and we know that the PC1640 differs in the area of the floppy interface. That is probably why the author used 'generally'. I am expecting that you will need to use the S0 setting (first drive-select setting).

Maybe someone here who has tried a GoTek in a PC1640 will confirm.

 

[coolchilli]

so... a month later, my bag of jumpers has arrived from China. Switching the PC1640 on this morning, and the screen initialises OK, but the base unit power cycles. Doesn't seem to be a loose connection, and judging from the faint whine the monitor is making without the DIN-14 plugged into the base unit - I'd say it's time for a recapping of the power supply circuitry in the screen...

... so this project will need to go on hold for a little while until I get a chance to do some soldering. Will report back though - rest assured!