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How to mount a GOTEK emulator into an Amstrad PCW9512

Hi. It is possible to convert .EMS autoboot files to run in CP/M? I'm not able to load autoboot images yet.
Another question. Anyone has loaded Locoscript from Gotek?
Thanks.
 
Hi, the problem is I can't load autoboot images in my gotek. If I load CP/M first (making the swapping method) I can load any CP/M image executing the .COM file without problems. But autoboot images doesn't work. So I was asking if there is any way to "extract" .EMS files from the autoboot images to make it work under CP/M or any other method to load autoboot discs. Locoscript is also an autoboot image, so I can't load it to print my old works in the daisy printer.
 
Do you mean line profile.sub? eg: https://forum.vcfed.org/index.php?threads/autoexec-bat-for-cpm.63383/

Or do you mean instead of the .EMS CP/M file?

Hopefully John will come by and correct me where I'm wrong, but I think the boot sector loads up enough to go looking for the EMS file. You could patch the boot sector, or load CP/M and use profile.sub

Or you could copy a suitable boot sector from another disk possible also...

It's something I'm only recently playing with, and I have some success, but not always. I'm still finding my way there.

David.
 
The boot sector loads the EMS file. If the disc image is for an 8000-series PCW and you want to load it on a 9512 (or vice versa), you need to alter the checksum of the boot sector. The 8-bit checksum of an 8000-series boot sector is 0FFh and of a 9512 boot sector is 01h. The byte at offset 0Fh can be changed (increase or decrease by 2 as appropriate) to make the checksum come out right.

I'm not aware of a CP/M program that manually loads and launches an EMS file, but I don't think it would be too hard to write one.
 
Hi again. After lots of try and error, I found that my dsk files, even the 9512 versions, where made for 360k units, so my pcw9512 was unable to run them. I doble-step those .dsk with HxCFloppyEmulator and now are running propperly.
Now I have another question: Can I load 8256/8512 images in my 9512 using the Gotek and doble-step to make 720k images? I tried, but doesn't seem to work.
If any of you can do it, please, tell us how, because it whould be very interesting for 9xxx users.

And last question: My original Locoscript disk Spanish version died, so I'm looking for a DSK file. Any idea where can I find it?

A lot of thanks.
David
 

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To make an 8xxx disk run in a 9xxx machine ( assuming it can read the disk, since there are some circumstances where it can't ) - You just need to change the boot checksum from identifying an 8xxx machine to a 9xxx boot checksum. Then most of the disks boot OK, unless there's an actual incompatability,

I did write a program to change the DSK image file from 8256 to 9512... But mostly I just do it manually with another program I wrote. If you ned to do that, let me know and the program is pretty poor, but I can send it to you - it's written in freebasic if you want the source. It's just a command line basic tool for viewing files on Amstrad disks, moving them about, between disk images, etc.

There's a PCW wiki located at: https://www.habisoft.com/pcwwiki/doku.php?id=es:start
There's also the Amstrad forums where a lot of PCW users hang out.

David.

p.s. There are also format incompatabilities. You can sometimes get around these by interrupting the boot process.
 
Thank you for your fast reply cj7hawk.
I'd like to take a look on your programs to convert image disk files to 9512. I don't know how to change the boot cheksum (sorry), so if you explain me how to do it, I will appreciate your efforts.

I know almost every page with PCW image files, but I can't find Locoscript in Spanish in any of them.

Thank you very much.

David

To make an 8xxx disk run in a 9xxx machine ( assuming it can read the disk, since there are some circumstances where it can't ) - You just need to change the boot checksum from identifying an 8xxx machine to a 9xxx boot checksum. Then most of the disks boot OK, unless there's an actual incompatability,

I did write a program to change the DSK image file from 8256 to 9512... But mostly I just do it manually with another program I wrote. If you ned to do that, let me know and the program is pretty poor, but I can send it to you - it's written in freebasic if you want the source. It's just a command line basic tool for viewing files on Amstrad disks, moving them about, between disk images, etc.

There's a PCW wiki located at: https://www.habisoft.com/pcwwiki/doku.php?id=es:start
There's also the Amstrad forums where a lot of PCW users hang out.

David.

p.s. There are also format incompatabilities. You can sometimes get around these by interrupting the boot process.
 
Thank you for your fast reply cj7hawk.
I'd like to take a look on your programs to convert image disk files to 9512. I don't know how to change the boot cheksum (sorry), so if you explain me how to do it, I will appreciate your efforts.

I know almost every page with PCW image files, but I can't find Locoscript in Spanish in any of them.

Thank you very much.

David

@Davidhg2k

Sorry, I got badly offtrack with a few recent life events, but I've uploaded the file to Github so you can download it.

First, it's written in BASIC - So you need to download FreeBASIC.
Link: https://www.freebasic.net/

Then unzip it somewhere and get the .BAS source file from here.

Put that in the same directory where you unzipped the FreeBASIC compiler.

Then open a Command Line window, navigate to the FreeBASIC directory and type FBC64 CPMTOOL.BAS and it will compile the CPMTOOL binary.

Copy a copy of the DSK image file you want to change to the same directory (FreeBASIC directory)

You can then type CPMTOOL and it will run, and produces it's own command line. Type HELP to get the help, but the commands you need should be like this; (Assuming the image is called something like CPM8256.DSK and make sure you're working with a copy of the DSK image, because it WILL change it. )

MOUNT CPM8256.DSK A:
A:
DIR A:
STAT
BCOPY A: A: 1

And that's about it, then type EXIT or QUIT.

It will rewrite your boot sector with the "fiddle" byte set to force a checksum of 1, which will make an 8256 disk boot on a 9512.

It works the other way too, but I've used this to make 8256 boot-only games boot and work on my 9512, and tested it on real machines, and it seems to mostly work.

The program is VERY buggy, and I didn't fully understand CP/M when I wrote it, but it still has some useful features, and can usually move files between disk images without corrupting them ( but not always, hence always work with a new image. )

One day I'll write a simple version just to change the boot sector of a DSK image file, but for the moment, this still works.

David.
 
Glad to hear it :)

The only thing I'll add is that there are some slight hardware differences between the 8256 and 9512 so some software may have issues, but they are also close enough that often it works.

It should be possible to copy a 9512 boot sector to an 8256 disk too, but I haven't had as much success with that as I have with just changing the disk boot checksum. Though the failures I've had there might be buggy software also.

Mostly the only disks I want to copy over are games disks, so they don't use the different hardware.
 
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