Copying disks

[Kybo]

When I use the SD File manager to copy a disk; I get this:

______________________________________________________________

SD card file manager

(d)irectory

(t)ype out file

(D)ump file

(r)eceive file via XMODEM

(s)end file via XMODEM

(c)opy file

(R)ename file

(e)rase file

(h)elp

E(x)it

Command: d

STORAGE .DAT     512K

DISK01  .DSK     330K

DISK02  .DSK     330K

DISK03  .DSK     330K

DISK04  .DSK     330K

DISK05  .DSK     330K

HDSK03  .DSK    4872K

Command: c

File name to copy: DISK01.DSK

Copy to: DISK90.DSK

Copying...Ok.

Command: d

STORAGE .DAT     512K

DISK01  .DSK     330K

DISK02  .DSK     330K

DISK03  .DSK     330K

DISK04  .DSK     330K

DISK05  .DSK     330K

DISK90  .DSK        0

HDSK03  .DSK    4872K

Command:

__________________________________________________________

Why is the size of the new disk 0? Did I miss a config setting or something?

-Kybo

[fred_...@hotmail.com]

That seems wrong -- there should be lots more files there -- mine looks like:

Command: d

DISK03.DSK      337568

DISK04.DSK      337568

DISK05.DSK      337568

DISK06.DSK      337568

DISK07.DSK      337568

DISK08.DSK      337568

DISK09.DSK      337568

DISK10.DSK      337568

DISK11.DSK      337568

DISK12.DSK      337568

DISK13.DSK      337664

DISK14.DSK      76800

DISKDIR.TXT     1047

HDSK01.DSK      4988928

HDSK02.DSK      4988928

HDSK03.DSK      4988928

HDSK04.DSK      4988928

HDSKDIR.TXT     482

README.TXT      1712

STORAGE.DAT     524288

DISK0A.DSK      337568

DISK0B.DSK      337568

DISK0C.DSK      76800

DISK0D.DSK      76800

DISK0E.DSK      76800

DISK0F.DSK      76800

DISK01.DSK      337568

DISK02.DSK      337568

DISK15.DSK      337568

DISK16.DSK      337568

DISK17.DSK      337568

TDISK01.DSK     256256

TDISK02.DSK     256256

TDISK03.DSK     256256

TDISK04.DSK     256256

TDISK05.DSK     256256

TDISK06.DSK     256256

TDISKDIR.TXT    461

HDSK05.DSK      4988928

HDSK06.DSK      4988928

HDSK07.DSK      4988928

HDSK08.DSK      4988928

HDSK09.DSK      4988928

[Kybo]

I haven't loaded all the disk files. I'm using an Adafruit SD Nand chip/breakout board instead of a SD card (long story). The chip acts as an SD card & reader, operating using the same commands (has all the features of a card). I have to use Tera Term and Xmodem to move files onto it, but it doesn't take too long per file. Plus, I'm not interested in most of the DISKXX.DSK contents. Generally only want to use CP/M stuff.

Is there some reason that all of the files are necessary for the AD to operate properly? If not, I am back to my original question. I am trying to copy a *.DSK to be able to then format it. I am using standalone mode, I do not have the front panel (another long story).

Unless someone has an empty *.DSK that is CP/M formatted that they would let me borrow... ;)

Thanks,

-Kybo

[fred_...@hotmail.com]

Kybo - I suggest 

https://github.com/dhansel/Altair8800/tree/master/disks

Those are the files that go on the SD card. DISK01.DSK is CP/M 2.2 63K -- start with that and remove any files you don't want

(ERA *.* after booting, or be selective).

There is no "CP/M format" -- if you write E5 to all bytes of a disk, CP/M will consider it empty (that is how IBM 8" SSSD disks came

from the factory, and how floppy disk formatting programs leave generally leave disks). E5 is 11101001 which is a synch byte

A stream of these allows alignment to the bit stream from the floppy. Not as important for the hard-sector floppies, but CP/M

was originally on 8" 256k soft-sector floppies.

The Boot sector was Track 0, Sector 1

The CCP was Track 0, Sectors 2..17

The BDOS was Track 0, Sector through Track 1, Sector 19

The BIOS was Track 1, Sector 19..26

The disk parameter in BIOS then tells CP/M to skip the first 2 tracks, and the directory then begins on track 2. Note that the

DISKnn.DSK images are Altair hard sector disk images, with 300k per disk. It is a strange format...

Also, note that the file DISKDIR.TXT gives a directory for the images -- I recommend putting that on.

Also -- consider using HD (5MB hard disk) -- you can put two of these on. The HDSK images are a bit "anemic" -- only 256 directory

entries supported. I have a CP/M 2.2 bootable HD patched to 1024 directory entries. You can get that at

https://github.com/ratboy666/hd1024

two of these can be mounted (A: and B:) on the Altair-Duino, and two floppy disks (C: and D:).

The take-away really, is to begin with a bootable disk, and clear the directory. But, the strange thing is that the SD File Manager failed

for you on the copy -- can you send/receive with XMODEM? Maybe the SD FAT image needs refreshing (depends on the SD emulator)

FredW

[Kybo]

Thanks for the info, FredW!

I did download and install the DHansel github *.zip; that's where I got the *.DSK collection from. Once transferred, that's where I tried to do the disk copy and got the 0 byte size. I was planning on formatting over the copy.

I am running standalone, so I have Tera Term window running on my PC. So I have easy access/viewing to the source disks folder, not using onboard DISKDIR.TXT.

Yes, I can XMODEM back-and-forth, that's how I got the *.DSKs onto the chip.

I will try your HD and give a report back.

Thanks again,

-Kybo

[Kybo]

Tried FredWs HDisk image, works great!

Thanks, FredW!

-Kybo

[Mark Lawler]

I'm trying for a setup where I mount A: and B: as floppies and then C: as a hard drive.  Are the built-in floppy and hard drive boot loaders restricted to accessing devices of only the same type?  

When I try to mount a drive of a different type, then change to that drive letter I get a "Bdos Err on <drive>: Bad Sector" error.   Each time I run STAT it only sees devices of the same type that I booted from.

In message https://groups.google.com/g/altair-duino/c/dOWl9iuHMdI/m/b4Ja5Bp5AwAJ FredW mentions that "two [hard drives] can be mounted as A: and B: and the two floppy disks (C: and D:)".  Do you mind sharing how?  I keep running into the same error.

Thanks!!!

Best,

-Mark

On Thursday, February 18, 2021 at 9:29:39 AM UTC-8 fred_...@hotmail.com wrote:

[fred_...@hotmail.com]

Mark

The BIOS on that hard disk uses A: B: as hard disk and C: D: as floppy. You would need to rework the BIOS.

and.. not the boot loader -- it is the CP/M BIOS. The boot loader simply boots from a device (hard disk, altair floppy, mits floppy, and,

with updates, cromemco floppy).

That, in turn loads the OS and its drivers. Mike Douglas (deramp.com) wrote the BIOS support mits hd and mits floppy.

Source available on his site.

What you can do is patch the BIOS to flip AB and CD around. What is interesting is that is NOT useful for CP/M. CP/M will

want to load the CCP from drive A... a lot. You will need a floppy inserted pretty much all the time. Or patch the BIOS some

more to load from C instead. It is easier to just let the HD be drive A. The mits HD was 4 fixed/4 removable system. So that

leads to A/B.The floppies then make sense at C and D. This is CP/M, not MSDOS

But, if you really want this, I will help...

FredW

[Mark Lawler]

FredW,

You've already been a huge help!!!  No need for me to buck the system.  Rereading your two posts I was able to boot a hard drive as A and then mounted a floppy drive as first D, then finally as C.  Somehow I had in my head that SW 9 & 8 would do the A, B, C, D thing.  I kept getting DISK08.DSK as my C: regardless of what I mounted.  I finally figured it out.  Turns out when I boot from HD, 9&8 being set to 00 is the C drive when then mounting floppy after the Hard Disk Boot ROM has been executed (and 01 is D drive when mounting floppy after hard drive boot).  I had wrongly assumed 00 and 01 would still be A&B as that is how they are assigned to the hard drives when they were mounted and that 10 would be C and 11 would be D...

Thanks again.  Bottom line is I have A&B working as hard drives and C&D working as floppies.  I'm trying to dust off 35+ years of cobwebs from my Nova 4 and Kaypro II & 4 days... ;) 

Best,

-Mark