Amstrad updates - disc 2

Following on from the previous article post, as Bob would say, "you wouldn't let it lie"

I ordered some cables, actually for the printer conversion project, but as it had 2 x connectors on it, I hijacked it and used it for this first.

There was a LOT of trial and error & learning mistakes 'earnt' during this exercise and I would probably have been quicker and more efficient if I wasn't doing this late at night after long work/work days, but y'know someone has to do the day job as the EPs I work with all seem to be very work shy...

So, armed with screw-drivers, hacksaws and cups of tea... a hacking I went.

I thought I would just cut & splice the existing internal 4 wires that provide the internal 3" disc drive with power, I mean, it'll only be using the power one at a time, wouldn't it?  I had a niggling feeling that this would not work - mainly due to the fact the proper "external 3" disc drives" come with a massive PSU transformer at the back of them, which I kept in mind as I proceeded.

I also had to "trim" the connector down to the custom shorter cable as used to fit to the drive itself:

that will get a big splodge of glue-gun glue at some point.

I assumed that the failure of the drive was due to the power draw, ie. piggy-backing the extra drive was just pulling too much from the 12v / 5v for it handle two drives.

I tested frequently, as you know, you're supposed to do.  I knew what the wonderful noises were coming from the external 3" disc drive - it was the belt riding up the motor and hitting the bottom of the drive electronics board - not really a major concern, but I did remove it, unscrew the motor, clean up the spindle and attempt to move it down as far as it'll go in order to "pull" the belt just that tiny bit further out to put a tiny bit more tension on it.  It seems to work okay.

As you can see, I had to remember how to access the "other drive", |B is the way to do it in AMSDOS and just B in CP/M.  I thought a good test would be to copy a file from the |A drive to the |B drive.  Turns out I had a knackered 3" disc, as the casing was open I could physically see the scratched ring on the disc internals - once I threw that away and got another disc, it all worked fine, copied over nicely and executed no problem.

However, I did find that using DISCKIT3 to format the disc, did show multiple drives and gave the choice of A or B to format, but when invoking to format, it got to sector 0 and, well, hung... all power off was only way to proceed.  Not a major problem, I can just format discs on drive A, once they are formatted, never really need to do it again, just use them.

UPDATE: an interesting note here is that I have the same issue with this when using a PROPER DDI-1 disc drive connected to a 6128 all properly, external cable and external PSU.  Hmmm....

Then I looked at the wall & I noticed I have the carcass of the Spectrum +3 board (that was totally dead - potentially could have been revived, but not in my area of interest), I had already "borrowed" the 3" disc drive and internal cable from it previously - that was salvageable.  I looked at the new PSU that I'd purchased for it, I looked at the 4-cables power cable connector that was used internally to plug in the 3" disc drive... and then I thought, "well, there's my external power source, right there!"

I was wondering what the 4 wires were for? logic said the 2 black ones were GND, but the other 2? A quick multi-meter check and it showed that one was +12v and one was +5v.  Makes sense as the motor that spins the rubber belt around has a big [12v] stamped on it and I'm guessing the circuitry for the board itself will run from the +5v.  I was going to solder some wires to the connector directly, then I found:

https://www.cpcwiki.eu/index.php/Powering_a_CPC_6128_from_a_Sinclar_Spectrum_+3_PSU

and whilst that showed me which were the 12v and 5v (and the "stay-away from" -12v), I then looked at the motherboard and thought, "why don't I just cut out that area and I can just keep it as-is, job done?"

So that is what I did!  After proving it all works okay (and saved me buying yet another PSU), I'll cover the whole thing in glue-gun hot-glue to stop it potentially shorting out on anything.  If I were going to be professional, I'd probably fire up the 3D printer and make a proper little case. maybe, one day.

Well, would you look at that. It was fine, copied file over and executed absolutely no problem.

(I'm no movie director at midnight!)

One slight accident with a hacksaw later....

and a very dead Spectrum +3 motherboard has donated it's PSU and made me happy - the board is fried / dead / Norwegian blue / ex-board, only good for spare parts. shhhh!

Right, multi-meter time:

and this little bundle of mini-mess works fine now:

mission "nearly" accomplished:

after a little tidy-up:

it tucks in nicely, just far enough away to be useful / accessible, but not "in the way".  nice.

And as the universe would have it, at 11:44pm I thought I'd have a quick eBay check...and there was a post for a proper external 3" disc drive WITH cable for £100-ish.  Ah, F--- it, so I bought it, might as well have a proper one, y'know, just incase.

and as if the universe also knew, I found one on fbook marketplace, 2miles from where I live, collect only for £60.  sigh.  anyway, bought that one too! :-) a quick belt swap and clean up & it's working great connected to the "other" 6128 machine.

I also purchased a PSU for the 12v output so I can plug in and power the |A drive, interestingly the PSU allows up to 3amp, so I wonder if that would push that amount of amps through the board and allow multiple drives to be powered okay - as per my original idea.  again, I'll give it a try later on.

and in case you were wondering, I actually purchased a PC cable for connecting 3.5" and 5.25" disc drives together to a PC motherboard.  If you look closely you can see the edge connectors and push in connectors, they do a great job

After getting all this working, it then dawned on me "why" I bought that cable - it wasn't for this project at all!  It was for connecting the CPC Amstrads to an Arduino Teensy so that I can "PRINT" from the Amstrads, to an Arduino, then onto a Raspberry Pi and then to my laser printer (or web page)!

Oh, that's for another article post (I did actually complete this the next day, but will write up later)