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How to mount a GOTEK emulator into an Amstrad PCW9512

OK, figured out my own questions.
1) It's an issue with the disk detection routines. The Gotek needs an additional "OR" circuit ( functionally a negative AND ) between Motor and Disk Select lines so that it only works when BOTH are low. Introduction of a 74LS32 was suggested, and works OK. Now I can use the Gotek and the CF2 DD drive simultaneously. As I want to be able to read/transfer from CF2, I removed the 720 drive and placed the GOTEK there, so the GOTEK is Drive A now.
2) The images I had were fine, but the detection routines still spook the Gotek into not starting sometimes. So I have to remove the USB and reinsert it at times to make first boot. Then it boots just fine and both drives work. I can't boot from B: though so I can't boot from my CF2 system disks.
3) Locoscript was also being affected by the drive detection, so once I added the extra logic to the Gotek, it started working fine, and lets me save/load from B as well.

I am still looking for;
Any images of the Public Domain software released for this model. I found some other Amstrad PD on archive.org, but not specifically for the 9512. Can anyone offer a suggestion?

Thanks
David.

p.s. The 3D printed Gotek adapter I made up works great. Looks like it was meant to be in there. I just realized there's only few sites that can be used to upload photos, so I'll work out how to get pictures up here.
 
ajacocks said:
That looks very nice @cj7hawk ! Printed Solid sells a couple of beige filaments that are made to resemble the plastic colors that Commodore used. Perhaps one of these might be close?

https://www.printedsolid.com/products/jessie-pla-1-75mm-x-1kg-beige-500?variant=39502756380757
https://www.printedsolid.com/products/jessie-pla-1-75mm-x-1kg-tan-64?variant=39502751694933

- Alex
Click to expand...

Indeed, I was thinking that, but white was as close as I had, and I've ordered a "Milk" white in case it's closer, but it's difficult to get the right color in Australia. Also, PLA is very shiny, so I did some experiments over the weekend hitting them with a quick blast of matt spraypaint, and discovered the unprimed plastic absorbs the paint very effectively as the pigments seem to get absorbed by the plastic. That might also make scratches less of a problem, as long as I match the two colors somewhat, and it's not likely to wear out easily since there's no real contact with the surface when using. But I haven't painted this one yet ( I make some similar ones in Black for Spectrums and Amstrad console-style models. )
 
Looking forward to seeing results for your 3D printing, the mounting I bought on line has broken, thin as a wafer, I am going to reassemble gotek and run it outside the 9512 for now.
 
cj7hawk said:
Indeed, I was thinking that, but white was as close as I had, and I've ordered a "Milk" white in case it's closer, but it's difficult to get the right color in Australia. Also, PLA is very shiny, so I did some experiments over the weekend hitting them with a quick blast of matt spraypaint, and discovered the unprimed plastic absorbs the paint very effectively as the pigments seem to get absorbed by the plastic. That might also make scratches less of a problem, as long as I match the two colors somewhat, and it's not likely to wear out easily since there's no real contact with the surface when using. But I haven't painted this one yet ( I make some similar ones in Black for Spectrums and Amstrad console-style models. )
Click to expand...
looks great!
 
I need a print for my Osborne and online services are probably worth a look.

Not got it yet but I'm trying https://www.surfacescan.co.uk/ to make a full height Gotek mount and for ~£30 its being printed in PETG and polished.

If its good, I will get a new Amstrad adapter made up too.

Would you share your files as that mount looks really good.
 
Hmmm. 30 pounds for an adapter... That sounds a little too high... I could buy an old spectrum board for that much !

Prototype file attached. In celebration of my getting my first dedicated CP/M machine and getting my GOTEK working, since I too relied on threads like this and others for help - :)

So I'll return something to the community to share... I'll release this STL file under Creative Commons Share alike, attribution, no derivatives. ( CC-SA-ND )..

Feedback is appreciated - :)

Distirbution license: https://creativecommons.org/licenses/by-nc-sa/3.0/

David
 

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  • FDD-PCW9512-adjusted - Copy.zip
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Thanks for sharing, it looks nicely designed.

There is only one full height adapter for sale and its more than that, doesn't look well printed, its postage is more than that and it looks as if its in that material which snaps at the grain boundaries (or what ever their called).

Do you know any online services that are cheaper in the UK ?

What printer and material do you use, might need to justify one :)
 
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The biggest problem with designing something like a full-height caddy is that I have to have a full-height drive or a full-height bay specification to work with. I do work for museums at times recreating items that they simply don't have enough of, but creating an exact duplicate is a slow and time consuming task. Also, print time is based on volume, and the longer the print time, the more someone is going to charge you. That little caddy I shared is small and only takes about 4 hours to print, but a full height one would take at least an entire day.

The 9512 caddy I released today is based on one I designed for the ZX Spectrum +3 and was because I found the other Gotek adapters weren't all that great when I looked at them, but everyone used them and some people even sold them without changing them. But you couldn't read the display while your hands were on the console, and they stuck out way too far, which I didn't like. Because most of the design work was already done, I managed to disassemble my PCW9512 in a single day, repair it, figure out how to get my gotek working on it and then modify the design, print it and reassembled it the next day with it's new drive bay. 3D printers are good like that.

I use a Tiertime UP300 for most of my printing as it is very precise and has a good quality repeatable output capability. It's a commercial printer and costs around US$2500. But my second cheap printer I have is a Flashforge Dreamer Dual-Head which you can get on Amazon for about USD$700 I think. The single-head version is about US$550. ( just checked, my guesses were correct ). It's actually a very flawed printer, but making it work properly only costs around $10 of parts, and the rest it can print itself when you get it. These transform it from a cheap printer into a reasonable one, though the output isn't as good as the Tiertime.

I printed one of the caddy's up on the Dreamer and it came out OK, Actually, it was a very poor quality filament that cost me about US$20 including delivery, which was because it is a garbage filament. It took me a while to get it printing, but now it prints, the output looks nice, though for some reason it comes out looking a little hand-painted... Suits the era.

I would consider selling them online... Except that I'm in Australia and I'd rather that the community is able to get it a little easier than ordering one from Australia, and I'm not the most reliable seller since I don't have the time. So easier to share it out and give something back to the community and then at least anyone can print it up and more 9512's will be resurrected :)

If you really want to start using a 3D printer, you also need some CAD software to design with. Scanning is generally a pretty poor method to use, and I've watched the experts do it and looked at their outcomes, and I really don't like it at all. The tools I use are calipers, rulers, digital protractors ( interesting note - The Amstrad PCW9512 caddy angle is 7.5 degrees ) and then design from there, build, test, modify, repeat. Works well.

If you have a full height drive, and want to measure it up, and have access to a printer ( or get your own ) I might be able to assist with a model. Large flat sections print up well, and generally the layers don't cause too much of an issue. After that, it's all about getting the holes and shapes in the right place, and finally, about making it look nice. Part of that is how close it needs to be to the original, and how much it needs to change to accommodate the knobs, displays, buttons, etc. Simplay making something strong isn't that difficult. I 3D print LOTS of strong stuff. Handles, etc. Even my sliding door has a 3D printed mount for it's rails that has held up now for 5 years and still works as designed. A good design for printing is designed to understand where a 3D model will break and compensates for it. Most 3D printed stuff is relatively strong, and even the failed print I had yesterday is probably good enough that most people would regard it as acceptable. The caddy is probably stronger than the rest of the Amstrad ( And it does get very knocked around when you put the top back on... Seems to need a little force... Typical Amstrad. )

Let me know if you want some assistance designing up your full height adapter.

David.
 
That one looks pretty good. Someone spent a bit of time on it.

I was thinking that if you modeled it after the old Shugart, you could hide the USB port and buttons beneath the drive-lock lever, so that they were hidden, but it looks like simply adapting the default Gotek 3.5" drives is a good option too.

BTW, do you know about the need to add a 74LS32 when connecting the Gotek up to the 9512+? You can take a jumper from DS0, MOT, 5v and GND and run the inputs into a single OR gate, then connect the output to the other pin on either DS0 or MOT inputs. Otherwise the Gotek will select when you go to either drive, and you can't install a second drive.

That was the final step that tripped me up. The 74LS32 is the small blue heatshrink item on my adapter.

Regards
David
 
Yep, I have the gate in mine though its a 9512, trying to fool the ready signal to detect the drive properly.

Have you managed to boot your 9512 so you can run 8256 programs ?
 
That's an interesting question. My 9512 reads 180K disks OK. Is there something there I need to know to make it run? I haven't tried loading an 8256 program yet - I'm still at the point of just working through the OS and getting the different programs to run. I only found some 9512 software for the first time last night, but haven't tried it yet. Is it something to do with the detection routines?

Thanks,
David
 
I have found that if you do the intial boot using the 9512 disk (the bit with the lines down the screen), then swap to the disk for the 8256, then it loads and runs all the 8256 software without a problem including the games that wont run if you boot it fully with the normal 9512 CP/M disk.
 
cj7hawk said:
Do you have access to a 3D printer?
Click to expand...
No mate but I am looking around, I was really disappointed with the mounting I bought that broke. I may buy a 3D printer or get one for Christmas. its holding me back from the good stuff I want to do to see my 9512 running. Liking this thread guys keep it coming.
 
Hello,

I'm somewhat mystified regarding the comments just now about swapping the disk during the boot process. This should lead to disaster. This needs a fair bit of clarification.

most of the PCWs are just the same system, only the (?) 9256+ is a little different. All should be able to run the same software. If there is something to stop this, then it's a very specific something and there will be a way around it. So as far as software for your machine, you can be looking at anything for 8xxx or 9xxx machines, and if there's something that seems NOT to work, then we find out why there's a 'problem' and fix it.

For example, the only thing that makes any sense regarding Gary's comment about swapping disks is that the boot process may involve multiple stages. Firstly, the loading of the .EMS/.EMT System file, this CANNOT be interrupted as described. But this may be followed by the loading of one or more .FID drivers, which again, should not be interfered with, but if there IS a problem with one of them then you simply rename the file to deactivate it, and this will prob. be followed by the running of the PROFILE.SUB, the CP/M equiv of DOS's autoexec.bat, and it may be possible that something in that may be causing a problem and the disk swap might stop that something from loading. I'd need to see what's in the disk dir (re any .FID files that might be there) and see what's happening with the PROFILE.SUB.

But again, just about any PCW software should work on any PCW. Though there may be the occasional Copy protection issue, esp with games, for example some games that expect to run from a 170k A: drive might do a check of space available on the disk and refuse to run if the result is wrong, as it would be if you run from a CF2DD disk on a 9512.

Geoff
 
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