Can my PCW live again? Gotek / FDD query!

[torrind]

Hi All,


I've just joined this wonderful forum and have resurrected my beloved PCW8256 last used around 25 years ago. I discovered that the drive didn't work and so after searching around, replaced the drive belt which seems to have fixed it.


However I have some issues. My Locoscript system disk intermittently loads but more often than not, I get a "disc address mark missing" error loading "script.joy". Sometimes if I keep pressing <enter> to reboot, it can work.


I'm not sure if its the drive or the disk is failing as I have no other system disks to use.


My other option is to use a Gotek drive and I know they've been used but I have no idea how to connect it. I do have one flashed to the latest FF firmware and have bought a 34 pin to 26 pin adapter but cannot get it working.


I've searched this forum for help but from what I've found assumes experience in these matters I don't have.


Can anyone help provide me with a step by step idiots guide for connecting a Gotek drive to a PCW and what files I need on the USB stick please?


Any help would be most appreciated.


Darren

[GeoffB17]

What you describe suggests that the floppy drive is probably OK now, with the new band, but there is a fault with the disk.   If it's just one file, then you can get around this.   Assuming that it's the data area of the disk, then just rename the file, and write a new version of the same file onto the disk, the old file, still there, will cuntinue to 'reserve' the possible damaged bit of the disk.

In case you're interested, the error message means that the format data is damaged, which might or might not incl the actual data.   The fact that it will, after numerous retrys or restarts,  read the data suggests the problem is marginal rather than total.   The act of 'formatting' the disk writes a lot of markers onto the disk, in fact creating a lot of numbered/marked 'boxes' on the disk for data to be inserted into later.   Hence the 'disk mark missing' error

Of course, if you got the system booted, you might find other files with a problem as well.

What version of LocoScript is it?   If you've got SCRIPT.JOY this suggests an older version.  I have an original system disk with that file, but it's not for sale or anything!   But, if it's the right version, something could be done.

Do you have the CP/M boot disk?   Your posting suggests NOT.

I have a Gotek drive, just sat here.   Like you, I understand that it should be possible to get it working, but I've not YET bothered to persue this.   As I have a fully working 3" disk A, and disks, and optional working 5.25 and 3.5" B drives, and 13 @ 8 Mb virtual HDs attached via JonB's uIDE add-on, I don't really need the Gotek.

Any way I can help get your Loco boot disk working?

Geoff

[GeoffB17]

Regarding the Gotek, as I understand it, you need to connect the drive in a special way as the idea is that the Gotek appears to the PCW as a normal 3" drive.   Not sure how possible it is to connect as A: or B:, but if it's A: then I'd assume you can use ONLY 170k images, but if it's B: then you should be able to use 170k or 703k images.   You'd need it as A: to be able to boot.

Then you can have xx separate image files on the USB stick (or SD card ?) and whichever image is selected is the disk that appears to the computer.   I don't think there need to be any specific files on the stick, or loaded on the computer, things are handled by the firmware in the Gotek.   It's all in the connection so that the PCW sees the drive as a normal drive, and I assume the getting of the original boot image onto the stick.   But if it's used as a B: then it doesn't need a boot image.

I think some people use them with an A/B switch so it can be used as either A: or B:?

Geoff

[torrind]

Hi Geoff,


Thanks for the reply.


I am using Locoscript v1.20 and TBH, it does point to a dodgy system disc. I do have CP/M on the other side but that does not load at all. I get sector 0 errors etc.. with an Abort Retry or Ignore error message.


I know nothing about the "JonB's uIDE add-on" Is this an SD card based HD? If so, that sounds like a good option to pursue. Do you have any further info on how I obtain one and how to connect it?


Again, many thanks for taking the time to respond, it's very much appreciated.


I'd like to keep the 3" floppy option, so I may try to make further enquires as to buying working system disks if I can...


Darren

[GeoffB17]

The errors you mention could easily be caused by a floppy drive that isn't tracking the tracks correctly, or even a drive head that needs a clean.   No way to be sure unless you've got a known good disk to check, and your disk clearly isn't reliable anyway.

I'll see what I can find re Loco 1.20, that may well be later than the version I've got.  But I've got various versions incl SPELL and FILE and MAIL, but these may not be compatible with any documents you already have?

I could just stick the versions I have onto a disk, and send you that.   It'll answer the other question, is your floppy drive working OK?

Yes, the xIDE thing is VERY neat.   Check down this section of the forum and you'll find a chunk of info about it.   I was able to get a complete one, Maybe only kits available now?   The device attaches to the expansion interface on the back of the PCW, and the little card with the works on uses a DOM, 128 Mb (Disk On Module) which is a sort of industrial variant of a CF card.   CP/M cannot access 128 Mb, so the card formats to 13 @ 8 Mb drives, which CP/M can access.   So I have drives C thru P (excl M: which is present already).   Using these drives is significantly faster than the floppy drives, on a par with M:, but of course permanent.   8 Mb is still pretty large for a CP/M drive, so it's well worthwhile using the USER areas to give, in effect, the function of DOS sub-dirs, and 208 separate 'disks' on line (13 drives, each with 16 user areas).   You need to use a later version of CP/M that supports FID extensions.   I use a J15CPM3 file, Jon supplies a .FID file which loads at boot and announces drives C:,D:,E: etc.


Geoff

[torrind]

OK So whilst I now have a twin Gotek system on my 8256, all works perfectly and I'm a happy bunny!


However, what is driving me insane with frustration is AUTOBOOT mode.


When I select AUTOBOOT.HFE, it boots perfectly and I can see all my files. I can assign different .hfe images to the 15 slots....


....BUT


How do you load a specific image from a certain slot (eg slot ? Pressing the 'logical keys' like ENTER or RETURN just add the currently selected image to a slot.


I have tried every key but to no avail - Obviously i'm missing something!




Darren

[Starglider]

OK So whilst I now have a twin Gotek system on my 8256, all works perfectly and I'm a happy bunny!


However, what is driving me insane with frustration is AUTOBOOT mode.


When I select AUTOBOOT.HFE, it boots perfectly and I can see all my files. I can assign different .hfe images to the 15 slots....


....BUT


How do you load a specific image from a certain slot (eg slot ? Pressing the 'logical keys' like ENTER or RETURN just add the currently selected image to a slot.


I have tried every key but to no avail - Obviously i'm missing something!




Darren

Hi Darren

This thread was started partly so you could get info on getting Gotek working with the PCW. Would you be kind enough to share very simple step-by-step instructions of how you finally achieved it for those of us who have come along after you that are looking for the same result? Much appreciated!

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic

[torrind]

Hi Starglider,


Apologies for the delay in responding - I've only just logged back on for the first time in a week or so...


I'll post what I did shortly...


Darren

[Starglider]

Thanks, I can't wait!

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic

[torrind]

Hi Starglider,

Apologies for the delay in getting back to you. Ok, so the following steps are how I got my twin Goteks working on my Amstrad PCW8256 - I'll assume you know nothing about anything, so please don't be offended if I'm teaching you to suck eggs! 

I've attached a few pix to illustrate and hopefully make things clearer.

1. Firstly, Flash your Gotek(s) to the latest version of Flashfloppy (mine are at 0.11) - There are plenty of YouTube videos on how to do this. I recommend using the Goteks internal flash feature to do this and not using one of those external USB HxC adapter thing-a-magiggies (I just found it easier).

2. Once you've flashed them, you will need an adapter cable to connect the Gotek Drive to the Amstrad ribbon cable (see my pictures) You can either make one yourself, or buy one. I got mine from a chap on eBay by being cheeky and asking him (he makes them for a few pounds) The eBay seller in question is called "Lemaru". (search for "Gotek USB Floppy Emulator Mounting Bracket - 3D Printed". Whilst this link is for the Amiga bracket, he does print the Amstrad PCW drive brackets too (as shown in my pictures). I highly recommend getting these printed yourself or by someone else as they are very professional. Im my case, Lemaru produced the Amstrad Brackets and two adapter cables for about £30 if I remember rightly.

3. Once you have the adapter cables and 3d printed caddies, take the Gotek boards out of their 3.5" enclosures and screwing them to the brackets, attach the cables with the adapter and screw back into the PCW case. Make sure you orient the bracket the right way inside the case (ie drive window at the top) as this will ensure the screw mounts line up inside the case.  (Note: The drive windows aren't for the standard red LED display only for those tiny LCD displays as in my pictures, again easy to install)

4. Once everything is connected and installed, power everything up and you should get the display as per my pic.....

5. To boot / load software, download some bootable Amstrad .HFE or .DSK images eg LocoScript or CP/M+ (these names are interchangeable and they also load if you rename them from HFE to DSK and vice versa) and place on a USB for the upper drive (these images need to be 195KB in length as the bottom drive is of a higher capacity and they won't work. Conversely, images for the bottom drive (778KB won't load on the top drive). Always boot images from the upper drive. Place all images onto the USB and use the buttons to scroll through them to select the image to load. If all works ok, the Amstrad should boot from them.

6. There are other whizzy things you can do like use a menu to select files and not rely on the up and down buttons to select them (I couldn't get this working hence this original query)

7. I think that's it - Please feel free to message me privately if you require further info - I hope I've explained it well enough??? If you get stuck with image files, let me know and I'll email them to you. I also have almost all games for the PCW so if you (or anyone needs any games, I'll see if I have them and send to you!!).

Darren

[torrind]

Here are the attachments I couldn't add to my previous post

[Starglider]

This is astonishing and amazing! Thank you so much.

Just 2 things come to mind:

1. Are you saying I can't use the standard Gotek LED display with this? Where did you get your LCD display versions?

2. I have a lot of original 3" disks that I want to keep using. But I also want to be able to boot from Gotek. Might you know of a way to boot from drive B?

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic

[GUNHED]

To boot from anything else than drive A you need to hack the boot ROM. Since it's documented it shouldn't be a problem. 

[torrind]

@Starglider - Sorry if I didn't make that clear - Yes you can still use the red LED it just wouldn't fit in the window on the 3d printed caddy


@Gunhed - Thats useful info for point 2 - I'll investigate this myself, thank you.




Darren

[torrind]

Something I forgot, but is probably obvious so for completeness I'll still mention is connecting the power.


I just used standard circuit board jumper wires to connect from the existing Amstrad power leads (black - ground and orange 5v) to the Gotek GND and 5v connections




Darren

[Starglider]

To boot from anything else than drive A you need to hack the boot ROM. Since it's documented it shouldn't be a problem. 

Pardon me but I cannot seem to locate that after a Google and a forum search. Any pointers appreciated.

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic

[JonB]

To boot from anything else than drive A you need to hack the boot ROM. Since it's documented it shouldn't be a problem. 

Sorry Gunhed, but I think you are mistaken.

The PCW does not have a boot ROM. Instead, the boot code is force fed into the processor by the printer control chip, as explained here: http://www.chiark.greenend.org.uk/~jacobn/cpm/pcwboot.html

You can't hack the contents of the printer control chip, it is read only. There are ways to get around this to boot a PCW from, say, a hard drive, but they are complex and difficult / costly to implement. If you go this way, you also need to modify the EMS file so that it loads FIDs and the startup script (if you have any) from B: as well. Lots of work.

Fortunately, there is a far easier solution. If you want to be able to have a Gotek as one drive and a 3" floppy as another, yet be capable of booting from both, just install a switch on the 0/1 drive select lines that swaps them over; that way, when the PCW tries to boot from drive A:, you get to choose which physical drive is selected by virtue of the switch position.

[JonB]

How to wire up your select lines so that they can be swapped over with a switch.

These two diagrams should help. On the left hand side are the select lines coming from the PCW's motherboard ("S0 in" and "S1 in"). On the right hand side are the select lines on the two physical drives ("S0 out" and "S1 out").

The component in the middle is a DPDT switch (double pole, double throw) which has two positions.

In position 1, physical drive 0 is connected to select line zero and physical drive 1 is connected to select line 1 - as per normal, so the PCW will boot from the top drive.

 

Select drive 0 as boot.jpg
(693.76 kB, 1701x556 - viewed 96 times)

In position 2, the select lines are reversed, so that physical drive 1 is connected to select line 0 and physical drive 0 is connected select line 1. The PCW will boot from the bottom drive.


 

Select drive 1 as boot.jpg
(697.41 kB, 1701x556 - viewed 96 times)

[robcfg]

You could have a modified rom on a Diagnostics board, but obviously, you'd need someone to write that rom code.

[JonB]

Quite right, Rob - but that is exactly the sort of cost / complexity that needs to be avoided, because it doesn't give you anything more than switching the select lines does (for this use case, anyway). Plus, you have to modify the EMS file too (as outlined above). I doubt Starglider wants to do that much work, just to be able to occasionally boot a floppy disk after replacing Drive 0 with a GoTek.

[robcfg]

Definitely!


I just wanted to point it out in case it’s useful for anyone.

[Starglider]

Thanks for the wiring schematic!

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic

[torrind]

Hi Starglider - Hope you're well.


I'm hoping you can help me - Did you manage to install your Gotek drives successfully? And if so, did you ever manage to get the wiring schematic working to switch booting between the A: and B: drives?


I couldn't figure out what wires to splice from the PCW ribbon cable? I made a hash of it but thankfully it didn't destroy my system?


If you have an idiots guide on how to do this, I'd be grateful.


Kind Regards,


Darren

[Starglider]

Hi Darren, unfortunately I haven't got tons l round to this, though it's on the list. It might be six months away though as there's a lot of projects on the list! I don't actually have the board yet, though if the creator wished to lend one to my channel it might speed up my featuring it ️

Thanks!, Starglider aka ԹҽɾíƒɾɑϲԵíϲ's RҽԵɾ๏ RҽϲíԹҽs
️ http://youtube.com/perifractic
️ http://patreon.com/perifractic