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Amstrad CPC6128 – Repairing the internal floppy drive

The internal drives in these machines need their own separate 12v supply. It's really quite a strange setup... as it means the power supply needs a male (positive on the inside) 5v DC jack and a female (positive on the outside) DC socket to get the machine up and running.

It all makes sense once you realise that the power was supplied by the monitor that came with the set. And since you don't want want the user to be able to get the plugs in the wrong order, having them oppositely-sexed means that there's only one-way-round that they can be connected... unless you try to connect the devices to themselves?

Anyway... I built the required power setup in the prevous post. This time around I actually have a set of strangely-sized Amstrad 3" floppies to test!

I bit the bullet and just tried to read the disks as soon as I got them... because, hey, sometimes things just work... Of course, no dice; it was either "no disc present" or "failed to read" each time. What next? Time to pull the thing apart! I really should've taken photos when I first did this as the amount of ... insect (I think?) debris inside the machine was intense. There were quite a few of either ant, moth or some other cocooning insect homes installed around the motherboard and, as expected, right inside the floppy chassis too. These things seemed to like to be near the warmer components.

There was also a very thick and protective layer of dust. The entire machine was pulled apart and 24hours were spent cleaning and drying. Again, I should've taken photos... but I was too scared to move everything on to the workbench. I didn't want a biohazard scene to break out. A lot of soap-suds later and the machine came up much nicer, but still had a pretty mottled outer-case.

Anyway, back to the floppy drive again. The discs weren't reading... so I watched them try to work whilst powered up. The head was happily scanning through the tracks, but the disc wasn't spinning. Turned out to be the age-old totally-trashed-drive-belt trick. Actually, when I first opened the case I should've realised that the 10mm x 5mm shards of black plastic (of which the texture should've been rubber) were chunks of the belt. They were actually so solid that I didn't recognise that they could've ever been elastic or soft!

Yup, those chunks above are the remnants of the belt. What to do? You could go on eBay and find a legit belt... or you could dig in your stationary draw for something like this.

And then, well, just undo all the screws on the underside of the drive, disconnect a cable or two and fit a rubber band. Be careful not to damage the band on sharp edges when you install it as you'll just be creating a weak-spot which'll tear when you least expect it.

Put everything back the way you found it and give it a go. I managed to get past the "no disc found" errors... but I still couldn't list a directory structure. I popped the disc back out and wiped down the head (there's a single-sided head in the drive, but the disks are double and need to be flipped) with alcohol wipes. No luck... but something occurred to me; there was a lot of play in the part of plastic that pushed the disc down onto the head... which meant that it wasn't actually properly being pressed down?

I gently pressed down on the metal plate that the disc actually sits on, just to see if there'd be better contact with the head, of which is under the inserted disc. Damn! It worked! I had no idea how to run LOGO3.COM, but the directory was there, printed in all its glory.

So, not enough downward force once the disc is inserted... how to fix? There happens to be a spring on either side of the 'floating' part of the chassis that the disc is supported on. I assumed that these springs were life-expired and weren't pulling down as hard as they should be. Probably explains why the disc doesn't 'click' in when you insert it either... it goes in and floats around.

Thanks to Jaycar, I purchased a box of springs. Actually, further thanks to Jaycar... they were free... as I received an AUD$25.00 giftcard in the mail for christmas due to my shopping last year!

Finding matchingly-sized springs was easy enough and installing them was pretty straight forward... just use tweezers to hook the inner loop.

From here, the 'click' was intense. Powering it all back up got me the following...

Snap. Just works(tm). Now... how do I even run Logo?

Nope... After a little googlin', turns out that it needs to be run from the CPM operating system... which is on the disk? Or something...

Getting somewhere...

And then... I have no idea how to use logo...

But win! I now have both an internal and external drive!

Amstrad CPC6128

A friend had one of these a very long time ago and I couldn't resist the urge to snap one up online when an auction came up! I'm really impressed with the size and design of this unit. It's quite heavy and solidly built. The keys have a nice tactile feel to them also.

The CPC6128 produces video through a 6-pin RGB DIN video port, so we'll need to convert that to something more usable. Thank fully I have a SCART to HDMI converter from the MSX. It also has a standard 3.5mm stereo output jack, so that can be fed into the SCART port also.

The internal floppy drive is non-standard. It requires 3" disks, as compared to a PC that uses 3.5". They're also slightly longer than usual disks. Fortunately Amstrad put an edge-connector on the rear for 'Drive B' which is pin-identical to old 5.25" PC disk drive plugs and I happen to have a ribbon cable that'll work.

Anyway.. let's get this thing powered up and running!

Power

The CPC6128 needs 5v @ 2A and 12v @ 0.5A. You'll also need power for an internal PC floppy drive.. so I've used an internal hard disk power supply splitter for my source. This was chosen as I have an external USB-IDE power supply which has the right power requirements for the whole setup.

I found a DC plug and quickly hooked up the 5v line (red wire!) to see if the Amstrad would power up.

Yosh! We have activity (red light illuminated in test above)! The 12v line is actually for the internal floppy drive, of which I don't have disks for, so I'm not too concerned with it. I proceeded and soldered on a floppy power plug, 5v DC plug and 12v DC socket.

After the final changes, the red power light was still illuminating, so it was now time to convert the video output.

Amstrad RGB to SCART

This looked similar to my MSX machine, but there's only 6 pins instead of 8. I followed the instructions here at CPC Wiki and created a cable with a 6-pin DIN on one end and a SCART plug on the other.

Initially, I used the first wiring diagram at CPC Wiki, but this didn't work! I got a quick view of the CPC, but the image wouldn't last. I then tried the Alternative RGB Wiring with LUM to SYNC and SYNC to 16 and we got a picture! I must admit that my SCART to HDMI convertor is noisy!

Note that the picture would blink and the OSD for my TV kept appearing telling me that HDMI 4 was connected. It turns out (as per the instructions on CPC Wiki) that you need to install a 10uf Capacitor across pins 16 and 18 to rectify this.

This was installed and fitted nicely in the plug-housing. Audio was then run through to a 3.5mm jack for the side connector.

Using a PC floppy drive

You'll find all the information you need here to connect a PC 3.5" drive to the CPC. Finding a ribbon cable will be the hardest part... but luckily I've had a few old machines pass through my pile'o'junk lately and there were enough older-style cables spare. I actually swapped a few cables out from older machines for standard newer floppy cables that don't have the edge-connector as the other machines won't ever need them.

We've already got the power plug from above, so all we need to do now is correctly plug the data cable through. It's as simple as pushing the edge connector socket onto the port at the back and then pluging the IDC header plug into the floppy drive. Make sure to get the cable on the right way... if your machine fails to boot at this point, then swap it around.

Final step... add a jumper wire between pins 33 and 34.

I must note that, when idle, the floppy drive's reading light was always illuminated. It also then illuminated the internal drive's busy light also!

I tried a standard 3.5" HD Disk.. but it hated it..

Floppy Disk Images

This was a little trickier. You'll find CPCDiskXP. The latter is a very power piece of disk writing software specifically for the CPC.

I tried initially to get CPCDiskXP to write a DSK file straight to my USB floppy drive, but it failed. It wanted to install a 3rd party 'direct access' driver and this then told me it wouldn't work with USB floppy drives. Fortunately, you can get around this by converting all images to 'usb floppy compatible' images.

Open CPCDiskXP and click the bottom-middle DSK Editor button. From here, choose 'New'.

You'll now be provided with a selection of floppy image formats. Select the USB Compatible radio and then choose a format from the drop-down that'll fit the contents of the disk in question.

Once done, hit Add Files From Another Dsk. Open the relevant disk image and select everything.

You should now see your new image populated with the files from the source disk.

Hit the Write USB Floppy button up top and make sure USB Floppy Drive is selected.

Make sure you have your drive connected and a valid disk inserted. (I didn't, so the next shot is dark and full of errors.)

And now... test!

Winner.

Other games: Prince of Persia, Stunt Car Racer, TMNT, Chase HQ, Spy vs Spy, Locomotion

Microtek MDC-1 Parallel Port Camera

This thing just looks cool! Advertised as 'really simple to use' since it only needs your parallel port, it's a true-colour 640x480 webcam for the Windows Millenium era. Well, I say Win ME, but I could be wrong... the drivers I found are for ME though, so it definitely hung around.

It has a lengthy cable with a little bit of 'interesting' at the end. Sure, you have the parallel port.. which we're expecting.. but then you have an 'adapter' that has male PS/2 on one end and a female AT keyboard connector on the rear. Wait... so... If my PC has an AT Keyboard port, I'm screwed because this has male PS/2... BUT I can plug my keyboard in to the back of it? Vice-versa, if I only have PS/2 ports, I then need an AT Keyboard? Maybe it came with an extra adapter when you bought it knew. Fortunately, I happened to find one in my box'o'junk!

So, in my AT case, I converted the AT to PS/2, plugged in the webcam and then plugged in ANOTHER AT to PS/2 to connect my keyboard! Hooked together...

We have power!

Software

Thanks to webarchive, the original page for the camera is here. Unfortunately, the snapshot they've taken doesn't include drivers. Regardless of the list of files here, they all seem to be for their scanners. Fortunately, Driverguide has a Windows Millenium Driver for the MDC-1. (Mirrored locally at this URL)

Downloading and installing was simple enough on Windows 98 SE. The software needed a reboot and then I had a program folder with Camera Test in it... sure! Why not?

Nice... it just worked perfectly. Terrible in low-light, but that's to be expected!

For those running open source software, you may be in luck. Is this a Linux Driver? Is this the same one? Maybe this?

Looks like they made sequels: Microtek Eyestar 2? And a USB version also.

Revolution 3D – Ticket To Ride – AGP Graphics Card

I didn't even know this company existed. I've recently acquired a box'o'crap and there was a really strange-looking AGP graphics card in it.

Turns out it's a Number Nine Visual Technology Ticket To Ride Revolution 3D AGP Graphics Card with 8mb of WRAM? There's more information on it here at the VGA Museum. Vogon's Driver Library has the drivers for it for Windows 9x! (Note that they're always in 7-zip format, so get the Windows 9x version of that here.) Here's Wikipedia's data on Number Nine Visual Technologies.

They actually used Beatles lyrics/song-titles for the names of their chipsets/cards. How very random. The card used the IBM RAMDAC and had WRAM ... of which I'm still trying to understand.

Wait... woah... the wayback machine not only has the original Number Nine Technologies website saved, but you can even download the original HawkEye drivers for this card!

So, crap 3D game performance and 'very good' 2D performance/image quality. The card has a 'VGA Enable' on it, so I assume, like early 3dfx cards, you could have this as a secondary and only use it when the application required it. Which is interesting; if the 3D is crap.. then you'd have a second monitor for crap-ness. Instead they supposedly actually were good enough for their 2D!?

Here's a demo of the 3D performance... browse right to the end to see Unreal. Here's a review of it on Tom's Hardware, pitted against a few other cards of its time. All under Windows 95! Shock, it didn't score good at all for 3D... but for 2D it wiped the field.

VC Collection (Russian) has a review of the card. I was happy to see it not coming last! Then I realised that it was being compared against an S3 Virge DX!

Installation

Software was instead pulled from vogons and running setup produced the following...

Wait, what? Setup won't actually install the drivers? It'll just install the control panel? Time to fight through Device Manager...

And, of course, it wouldn't be Windows 98SE without a reboot...

The desktop then rendered beautifully over VGA at 1600x1200.

Games!

Screamer ran very nicely... but this isn't a true 3D game. It has it's own engine and just renders as standard 2D.

Quake 2 was a different story. It ran 'OK' at 320x240. 'Sluggish' at 640x480 and 'Useless' at 800x600.

But that was to be expected as this is not a powerful 3D card!

Wavetables – PRO32AW

Whilst in Thailand I picked up an ISA card with a daughterboard. It was part of a collection of crap from a market where the SIMMs and card were rusting and .. well ... I took a punt!

Turns out the card was an ESS1868, but the daughterboard was an Avance PRO32AW! Talk about lipstick-on-a-pig! I suppose someone wanted the cheapest SB16 experience with a 'better' MIDI quality? It seems this is a clone of a AdMOS Adwave 32, down to just a simple text modification on the PCB. There's a site (Japanese) here that mentions this fact.

The Wavetable module plugs on the header on the sound card and (usually) then disables midi-out on the joystick port.

After a lot of tinkering, I worked out the following. To get a wavetable to work, you need to adjust the IDSP/ADSP jumpers.. where ADSP seems to be the additional DSP card. If you don't have jumpers (The ESS1868 didn't ... and my Vibra 16S/C also didn't), then you'll probably find a new Gameport Joystick detected when Windows loads... unfortunately, this will conflict with your original joystick port.

To correctly install a wavetable under windows, your best option is to entirely delete the soundcard from windows first! Remove everything from device manager (especially the Gameport Joystick!) and then shut the machine down. In this state, the card will be found a-new when windows loads and you shouldn't get resource conflicts. It seems that jumperless sound-cards disable the joystick output when a wavetable is added and then re-route the midi messages to the wavetable. The main confusing part was that the new 'Gameport Joystick' used the exact same addresses and resources as the conflicting port!

After getting it all to work, I managed to pass the audio through my laptop and record the output of each piece of hardware. Here's the source file from Mr Trachtman's Archive.

Here's the basic ESFM Synth:

Here's the Vibra 16 FM Synth:

And then the PRO32AW wavetable:

And then my beautiful Roland Sound Canvas SC-55.

And finally, a friend's Yamaha PSR (Thanks Nathan!)

Play all at once ...Muhahaha... Reset

I found the wavetable sound to be much better than the internal FM synth on the ESS1868. I actually don't mind the wavetable when compared to the SC-55, but was definitely hoping that the SC-55 would come out on top.

I wonder how I replace the soundfonts!?