I've made a minimal BIOS that works enough to load and run either of the CP/M 1.3 system builder binary files SR400.SYS or SR128.SYS as described in the Operating system system guide.

Disks are emulated using a disk image file that is just a binary dump of all the sectors from a standard disk in physical order.

However, there seems to be some problem with it in that only some images work and those that do fail when a single byte is changed. This is not a problem while CP/M is running, the image only fails when CP/M is restarted with the changed image. The error seems to be somewhere in the BDOS with it ending up in a loop constantly reading through all the directory sectors.

As I only have the BDOS as a binary I've not looked too hard for a fix yet.

I'm also missing some fundamental system programs like PIP, FORMAT and their ilk.


I think you may be able to do this with file I/O and a little software on the windows side using the files as pipes.


This as well, just have a cron write the date to a file every midnight.

Lee.

Ok, I just looked at my source to check and it actually loads the s-record versions of the BDOS, CPM400.SR or CPM128.SR, not the binary .SYS versions.

Lee.

Thanks for the tips Lee,

I found zips of the 1.2 source and 1.2 and 1.3 binaries at http://cpm.interfun.net/cpm68k.html on August 2. Must have gotten lucky because when I try the link now I get UNRESOLVED_HOSTNAME error. The 3 zips are around 600 kB each and I'd be happy to send them to you. I also found a disassembler for the PC. Haven't tried it yet, in fact this whole project is just a gedankenexperiment so far.

According to my User's Guide the FORMAT program supplied by DR was specific to the Motorola EXORmacs computer. Other computer vendors supplied their own versions of FORMAT.

-Bruce-

_________________
-=BWS=-

I've grabbed a lot of CP/M 68k from various places on the net in the past, a lot of which seem to be available here http://www.cpm.z80.de/binary.html including the 1.2 and 1.3 archives I think you have.

I've made the disk file format the same as the Motorola EXORmacs computer disk format so the FORMAT from DR should have worked. What I did was added the FORMAT.S code, with some necessary changes, to the BIOS code to get it to make a blank disk every time the BIOS started and it did create what looks like a valid disk file, but it didn't work.

I have a disassembler that runs under EASY68K but disassembling the BDOS is something that can wait for the shorter winter days.

What I'm not sure of ATM is what to do to generate a system disk once I have the BDOS and BIOS working together and what other things I'm missing to put on it.

There's quite a bit of CP/M 68k software that would be interesting to use under EASy68K, different languages, compilers and some classic games.

Lee.

Thanks for the link Lee. I didn't get an email--is that because you posted without quoting?

I'm not sure I'm following you on all this; sounds like you can get your BIOS to "format" a binary file on the PC's HD so it looks like a floppy. You would then need to INIT it to create a directory, I think.

I have a pgm called SYSGEN (from SORD) that makes a formatted disk bootable. When run it prints out:



Wish I had more time for this
--Bruce--

_________________
-=BWS=-

I've found what was wrong. I was using disk header and disk parameter values from an example BIOS and some of those values were incorrect.

I also worked out the difference between FORMAT and INIT. FORMAT does a complete, hardware specific, low level disk format writing each sector before initializing the directory. INIT just initializes the directory. You should only need to use FORMAT on a new disk and the empty disk image I've created is effectively already formatted and initialized.

On a side note there is a bug in the format source that means four times as many sectors are initialized than are used by the directory. This is harmless though as an the content of an empty sector is undefined.


It seems I will need to create most of those files for the EASy68K version of CPM. One utility I will have to do is a version of PIP that can copy files to/from the PC's drive via the AUX I/O channel otherwise I'm going to have to build disk images by hand.


There's never enough time.

Lee

Hi, Lee. I'd love to try CPM68k on Easy68k. I'm new to both, but have implement CPM80 on my IMSAI. Would you be willing to share your implementation? Thanks very much,
MT

PM sent.

Lee.

Any chance I could get a copy too ?
Would love to play on cpm68k again ...
Thanks in advance.

I would also love to play with CP/M 68K for EASy68k. Please let me know if this is possible!

Did anyone ever get CP/M 68K working in EASy68K? If not, does anyone know another emulator that can get CP/M 68K up and running?

Thanks!

I have a version that works but I don't have the CP/M 68K sysgen tools to make a bootable image.

Lee.

Could you send me what you have so that I could tinker with using it, incomplete as it may be?

same step for me:
Have CP/M68 running from the S-records and would need to add the BDOS-routines to r/w floppy disk images.
Anyone still has some information on that?

Hi Guys,
Been reading these posts with great interest.
I am quite new to Easy68K but am finding it to be a really excellent tool to work with.
I've done lots of MSP430 Microcontroller programmming which has an instruction set thats sort of a cross between 68000 and PDP-11 but haven't ever really programmed in 68000 assembler until now.
I am finding it pretty easy going though due to the above mentioned similarities to the microcontroller I have been using.

So to the point...........

I would really like to get a CP/M 68K up and running on Easy68K even if its not perfect so may I kindly ask if any of the code mentioned in the above posts might still be available as a starting point for my experiments?

Ultimately I plan on building a 68008 board with enough ROM and RAM to allow me to play with CP/M on some real hardware as well.

Regards

Lynton
England, UK