CP/M for Northstar Single Density Disk?

[smp]

Hello all,

As you have seen in my other post, I have successfully achieved a good, stable, working IMSAI system with Z80 CPU, 64K RAM, SIO and Northstar (single density) Floppy disk controller with 2 floppy drives.

I am presently able to boot NS-DOS, and use NS-BASIC. I have successfully used Dave Duffield's NST transfer program to bring a Northstar floppy disk image into the system and write it out to a floppy disk.

Next, I would love to acquire a copy of CP/M. I know that it was available on single density disk at some time, because when I've been scouring the Internet, I came across the Lifeboat Associates manual for it.

I managed to acquire a stash of Northstar floppy disks along the way, mainly to acquire the 10 sector hard sector floppy disks. These disks all happen to be double density, so I cannot read them with my system. And, of course, I have a master copy, as well as a few working copies, of Lifeboat Associates CP/M! So close! I have it in my hands, but my system cannot read the disks!

I have looked around. I got very excited when I saw the zip file called "NorthStar CP/M bootable OS versions" on Dave Duffield's site, but the zip file contains images of double density and quad density disks - no single density disks.

Can anyone point me to somewhere that I might acquire a single density Northstar floppy disk image that has bootable CP/M on it?

I have the Lifeboat Associates double density Northstar CP/M disk - does anyone want to trade for a Lifeboat Associates single density Northstar CP/M disk?

Thanks in advance,

smp

 

[TX_Dj]

Surely, somewhere, I have what you seek. My PCS 80/30 was originally a single-density system with a northstar controller, which was later converted to a Micro Complex double-density controller. If I have it, it's already in the archives. Ken Vaughn was very good about making sure that all of his disks and manuals were archived- he did this prior to the machine getting the smoke let out, which was before he handed it over to me, complete. I have a CD with all the archived data on it, but I know for a fact that his scans have made it into the archives, because on occasion while searching for things related to the problems I was having, I turned up copies of his scanned documentation.

I know he was more interested in Northstar DOS than CP/M, but probably had NorthStar CP/M prior to converting to double-density, after which I know he used Lifeboat Associates' CP/M for his CP/M needs. I'll go have a look at the disks and see if there's anything in there that appears to be single-density N* CP/M. I doubt I have a single density Lifeboat image, because if my memory serves, he says he didn't use anything but Lifeboat CP/M on double-density.

Either way, whatever I have for my system will still require your modifications to work with your system, but I suspect you already know that.

 

[TX_Dj]

This is what I have...

That's a Lifeboat release.

So, no, sadly, it seems that what you're looking for isn't in my archives. Also, all the 2.x CP/Ms from Ken's disks seem to be for DD.

There are other versions of CP/M in there, on single density media (though that doesn't mean much at all), so maybe there's still hope- but in order to get it bootable, of course, you'd have to have a way to write your CBIOS routines into the system.

 

[smp]

This is what I have...

That's a Lifeboat release.

So, no, sadly, it seems that what you're looking for isn't in my archives. Also, all the 2.x CP/Ms from Ken's disks seem to be for DD.

There are other versions of CP/M in there, on single density media (though that doesn't mean much at all), so maybe there's still hope- but in order to get it bootable, of course, you'd have to have a way to write your CBIOS routines into the system.

Hi TX_DJ,

I see the photo you posted, and, at least by the comment "single" written on the label, it would appear that the disk might be single density. Of course, it could also be that "single" means single sided, or single user...

I'm not sure why you say it is not what I'm looking for. Can you explain?

Thanks very much for your attention and effort!

smp

 

[deramp5113]

It does look like the disk from TX_DJ is what you want. You'll probably have to patch for console I/O, but Lifeboat made that fairly easy.

If you don't get anywhere, let me know, I have a source for NS single density CP/M 1.4 running on a Sol-20 that we could make work.

Mike

 

[TX_Dj]

I had said not what you were looking for, because I believe you said you weren't looking for a lifeboat release, but instead something that N* put out directly. Perhaps I assumed wrong.

It should be in Ken's archives, I'll dig through my copy tonight if I can remember exactly where I put the CD, and then we can see if it's in there. If not, as we talked about in PM, there are other options.

Plus, as Mike says above, it seems he has essentially the same - so perhaps his will work for you as well.

Keep in mind, these are all 1.4x CP/M, not the 2.x CP/M that most people think of when they think CP/M.

I likely have the docs for this release also, which again should be in Ken's archives which were published in various places as well as his disk data.

 

[glitch]

I FINALLY HAVE COPIES TO SHARE!

Martin Eberhard got me a copy of CP/M 1.4 for single-density North Star controllers. The copies I have also appear to be Lifeboat Associates. As far as I can tell, North Star never released their own version -- I guess that's not surprising since they had their own North Star DOS, which came with the controller.

The copies I have are virgin factory media (no I/O routines) or generated for the MITS SIO-B serial console. I've written a definition for Dave Dunfield's North Star simulator that successfully boots the MITS-generated images as they are. I haven't finished documenting them and making actual generated copies for my systems' I/O, but I can make the images available now if anyone needs them.

TX_Dj, can you make NST images of the single-density disks you have? If you have no way of producing copies/images of your disks, I'd love to get my hands on them for imaging.

 

[smp]

Martin Eberhard got me a copy of CP/M 1.4 for single-density North Star controllers. The copies I have also appear to be Lifeboat Associates.

Glitch sent me a copy of the CP/M 1.4 disk set for the single density Northstar controller. I used the Lifeboat instructions I obtained out on the Net to patch my I/O, and I successfully got CP/M up and running. Thanks a million, Glitch!

Next, I have to dive back in to the Lifeboat instructions and learn about relocating CP/M to take advantage of more memory...

Hallelujah !!!

smp

 

[smp]

Hello again, all,

I am happily working with my IMSAI system with Northstar single density controller, with either Northstar DOS v5.1S or with Lifeboat Associates CP/M.

The CP/M system is generated for a 16K system (with Northstar, that means you must have 20K RAM). I have attempted to try the Northstar relocation command (NRELOC) in order to relocate my system up into high memory, since I have 64K RAM with my system monitor at F000 and the Northstar bootstrap at E800 and E900.

So far, no luck. I have been able to see that the system generates a 54K CP/M system and locates it up at C100 and above. I also reassembled the bits of code I need for my user I/O routines, and I see they are properly located at DC00. As a check, I calculated that a 54K CP/M system should have its jump table at 3E00+bias, that's 3E00+9800=D600, and yes, it is there. So, I've gotten it all in memory, and I've done the proper commands to save it off to disk. I have verified that it all comes back in properly when I boot the disk. The only problem is that I get no I/O after the system boots. The best I can figure is that the system boots but it is not properly associated with my new I/O code.

I checked, and, yes the CP/M jump table has proper jumps to my bits of I/O code. So, I'm stumped.

Has anyone else gotten CP/M working with a Northstar single density controller, AND successfully done a relocation for more memory that the original 16K system?

Thanks for listening...

Next, I'll see if I can get things to go as a more standard 48K system.

smp

 

[Chuck(G)]

It should be known that, by and large, Lifeboat didn't do the CP/M adaptations for a given system on their own. Rather, they took code from OEMs and others and packaged them up with few changes and offered a retail outlet for them. Most OEMs did not want to get into the onesy-twosy retail end of the business.

 

[smp]

Next, I'll see if I can get things to go as a more standard 48K system.

OK! I've solved my problem.

What I was missing was that the NSYSGEN was regenerating the original UNPATCHED bits of user I/O code. Since my code is *very* much the same as the unpatched code, I was not noticing that it was not *my* code when I checked that it was properly placed in memory.

I now know that I have to load my newly assembled bits of I/O code *after* I boot the newly sysgen'ed code into memory, and not before as I had been doing it. Then I have to do the patch save again, as I did the very first time.

The instructions provided show a variety of ways to get things done, and never show one detailed step-by-step way from start to finish, so I messed up the order.

Now that I have a good copy of 48K CP/M, I'll probably stand pat with that for the time being. That's most likely a large enough memory area for me at this point.

Thanks again for listening...

smp

 

[griffk]

Hi from another IMSAI owner!

You can always patch the initial I/O code you wrote to do a HALT immediately, and then (because you have a full front panel) single step into your code and see where it goes...

Do you immediately jump to your controller code, or do you send out some sort of boot prompt on the serial port? I think I would send out a Heartbeat prompt (with maybe even more than one interspersed through your code (with diff ascii to tell where you are).

Once you know that the boot is ACTUALLY getting to your I/O code, it a simple matter of doing a 1975 "printf" at various places in your code, and tracing through....ha ha "simple" :}

 

[shirsch]

Are you not able to find CP/M 2.2 for the N*? I have single-sided CP/M diskettes that boot on my 64k Horizon. Are you setup with Dunfield's NST and able to write diskettes from image files?

 

[smp]

Are you not able to find CP/M 2.2 for the N*? I have single-sided CP/M diskettes that boot on my 64k Horizon. Are you setup with Dunfield's NST and able to write diskettes from image files?

All the copies of CP/M 2.2 for Northstar that I've found have been double density disk images, and, as I've repeatedly stated, I have the earlier single density Northstar controller.

I even have a physical original copy of Lifeboat Associates CP/M 2.2 for Northstar - on a double density disk.

Yes, I'm set up with Dave Dunfield's NST.

smp

 

[deramp5113]

CP/M 2.2 for the single density Northstar controller has been on my list of projects for a while now. I'll publicly state it here so that it will move up on my priority list!

Mike

 

[smp]

Here's a new question:

If I were to acquire a double density Northstar floppy disk controller (MDS-AD or MDS-AD3 vs the MDC-A4 I have now) can the double density controller read and boot from a single density floppy disk?

Thanks,

smp

 

[deramp5113]

Yes, the double density controller can read and write single or double density. Northstar CP/M 2.2 requires the DD controller and can detect and operate with either SD or DD disks.

Note, however, the SD and DD controllers have slightly different register locations/functions so software that expects the DD controller (e.g., Northstar CP/M 2.2) will not run on an SD controller and vice-versa.

Mike

 

[smp]

Yes, the double density controller can read and write single or double density. Northstar CP/M 2.2 requires the DD controller and can detect and operate with either SD or DD disks.

Note, however, the SD and DD controllers have slightly different register locations/functions so software that expects the DD controller (e.g., Northstar CP/M 2.2) will not run on an SD controller and vice-versa.

Mike

Hi Mike, and thanks for the tips.

From my other thread, I now have a working Northstar MDS-AD double density floppy disk controller.

Since I have a bunch of single density floppy disks that work with my Northstar MDC-A4 single density floppy disk controller, I tried to boot with the double density controller, but it would not boot. It tries 10 times and then gives up.

Please tell me more about the "different registers" in the double density board versus the single density board. I am not getting it. I understand the boot process of going and reading one sector into memory and jumping to it, and then that code reads in the OS from there. Is the double density board supposed to somehow automatically figure out that the diskette is a single density diskette? I'm getting confused.

Thanks very much, in advance, for your thoughts and advice.

smp

 

[deramp5113]

The DD controller can read files from a SD disk, however, all we're talking about here is media interchangeability. The controllers themselves are not software compatible. If you try to boot a SD disk that has a CP/M BIOS written for the SD controller, the boot sector may load from disk into memory, but the code in the boot sector (like the BIOS) is written for the SD controller, not the DD controller, so it won't work.

Mike

 

[smp]

The DD controller can read files from a SD disk, however, all we're talking about here is media interchangeability. The controllers themselves are not software compatible. If you try to boot a SD disk that has a CP/M BIOS written for the SD controller, the boot sector may load from disk into memory, but the code in the boot sector (like the BIOS) is written for the SD controller, not the DD controller, so it won't work.

Mike

AHA! Thanks for the explanation. I get it now.

I suppose that holds for the Northstar DOS, too, so that's why I can't get anything to work. All my code is for the single density controller.

Thanks!

smp