MAI 2000 QIC tapes / tape drives

In this document:

The original tape drive in the MAI 2000 (Model 4403) was a Tandberg TDC3390 (Consist of drive TDC3309 and formatter board TDC3350). The formatter board was equipped with a standard QIC-02 intelligent interface.


Recording format is 9 tracks, the capacity is 45 MB on a 450 feet, 60 MB on a 600 feet cardridge. Format used is QIC-24.

The service manual for the Model 4403 is available here or at bitsavers.
A datasheet for a similar drive from Wangtek is avalaible at bitsavers.

QIC formats:

format
 tracks
 MB
 tape length
feet
QIC-11
 4
 20
 450
QIC-24
 9
 45
 450
QIC-120
 15
 125
 620
QIC-150
 18
 150
 620
QIC-525
 26
 525
 1020


Formats supported differ by drives but i know no drive > QIC-24 that can write the QIC-24 format.


 Wangtek Archive Tandberg

5099 5125 5525 Viper 2125 Viper 2150 Viper 2550 Anaconda 2750 Anaconda 2750 SLR7 SLR5 SLR4 (TDC4200) SLR3 SLR2 (TDC3800) SLR1 (TDC3600)
QIC-11 - - - - - - - - - - - - - -
QIC-24 R/W R R R R R R R - - R R R R
QIC-120 - R/W R/W R/W R/W R/W R/W R/W - - R/W R/W R/W R/W
QIC-150 - - R/W - R/W R/W R/W R/W - - R/W R/W R/W R/W
QIC-525 - - R/W - - R/W R/W R/W - R/W R/W R/W R/W -
QIC-1000 - - - - - - R/W R/W - R/W R/W R/W - -
QIC-2GB







- R/W R/W - - -

This means that if you want to write tapes under linux and read them with the MAI system, the drive in the MAI has to be replaced by a model with more capacity. The interface used in the MAI is QIC-36, so any drive should work. I have used a Tandberg 150 MB model. Here some drives with QIC-36 interface:



Wangtek drives tend to have a problem with the capstan roller used to transport the tape. The roller will transform to liquid and ruin the tape. I have 2 drives with that problem here, i would suggest not to buy old Wangtek drives. The models from Tandberg and Archive i have do not show this problem at all. I got all the drives i have from ebay for less that €5.
There were also QIC-24 drives with scsi interface available, for example Caliper CP-60S but i have never seen such a drive.

How to read tapes on a linux machine

For the linux machine, you need an SCSI model. In the past i used a Wangtek 5525 but due to the capstan roller problem i changed it to a Sankyo CP 525SE (€1 from eBay).

For controlling the tape, you need mt (control magnetic tape drive operation). For fedora, the package "mt-st" needs to be installed, for other distros find the package providing /bin/mt, on yum based distros with "yum provides /bin/mt".

The contents of a tape can be read with a small script:

SESS=1
DEV=/dev/nst0
echo "Rewinding Tape"
mt -f $DEV rewind
while [ 1 ]; do
S=`echo $SESS | awk '{ printf "%04d\n",$1 }'`
echo "$SESS  $S"
dd if=$DEV of=S$S bs=512 || exit 1
SESS=`expr $SESS + 1`
done

This script will rewind the tape and read all files on tape into the local files named S0001 to Snnn.

If you do not have access to /dev/nst0 as non root user, check the group of /dev/nst0
[ad@media ~]$ ls -al /dev/nst*
crw-rw----. 1 root tape 9, 128 Jun 14 19:01 /dev/nst0
crw-rw----. 1 root tape 9, 224 Jun 14 19:01 /dev/nst0a
crw-rw----. 1 root tape 9, 160 Jun 14 19:01 /dev/nst0l
crw-rw----. 1 root tape 9, 192 Jun 14 19:01 /dev/nst0m

and add the group (tape) to your account (as root and you need to logoff and login after the group is added):
usermod -G tape YOUR_USER_ID_HERE


How to write tapes on a linux machine

When writing tapes, the density should be set so that the drive in the MAI machine can read the tapes. As mentioned above, almost none of the 120,150 or 525 MB drives can write the 45 MB QIC-11 format. So adjust the format matching to the drive installed in the MAI. I'm using a 150MB Tandberg drive in my MAI 2000, so the density code to use is 0x10.

#0x05   QIC-45/60 (GCR, 8000 bpi) [not writable]
#0x0f   QIC-120 (GCR 10000 bpi)
#0x10   QIC-150/250 (GCR 10000 bpi)
#0x11   QIC-320/525 (GCR 16000 bpi)

#set density to 150MB
>mt -f /dev/nst0 setdensity 0x10

now you can simply write data to the tape. If you want to write a diag tape, simply dd all files to the tape.
The MAI does not have tar or cpio istalled. In addition dd (=debe on the MAI) can not access the tape device (/dev/cs). The basic interpreter has also no support for 1/4" streamer, only the 1/2" MTS is supported.
That means, the only way to read and write data from the tape (i have no c compiler due to the missing BOSS/IX tape) is tsave and trestore.

How to backup the bootdisk (wd0) on the MAI 2000

My problem was a noisy harddisk that also had sometimes read errors. So i decided to change the disk. I got 2 seagate st1100 (3,5", 80 MB) on ebay to replace the Maxtors.
It is important to backup the config record (contains serial num, owner, max memory, max disks and so on), without that, the OS will not start.
In case you have a replacement disk with same #of tracs, sectors and heads you can use dutil from the diag tape to backup the disk. Boot from the diag tape, at the <exec> prompt, enter

load dutil

when dutil is loaded, enable retry and ecc (this will not write to disk but does not work without writeok)

writeok
retry 50
ecc
readonly

now do a read test of the complete disk, the backup only works if every sector can be read:

dread

If that was ok, you can start the backup, enter

dutil

to show the dutil menu, select readonly utils and backup disk 0.


Writing other data on the MAI to tape

The MAI BOSS/IX (=µnOS from Charles River Data Systems) does not have tar or cpio. In addition, debe (=dd) can not write to the 1/4" streamer device (/dev/cs). So the only way i know is the backup program provided by MAI, it is called tsave.


tsave dev=device [options] {files}

Options
list=filelist_file
-recursive
-verbose
-filesystem  (image backup of a filesystem not currently mounted)

Backup all:

tsave dev=/dev/cs -v -r /*

To include the boot partition, mount it before running tsave:


mount /dev/boot /mnt

The device name may be different, do a ls -l /dev | p and search for a device 14,01, this is the first partition on the disk. On systems were a diag partition is installed, the boot partition may be the second one (have not checked this).

Save the config record

I think there was /bin/iconf for working with the config record, as far as i remember, iconf can display, read and write the config record on wd0 only, no way to copy it to a second disk.


Replacing the boot harddisk (wd0)

I have made this 5 years ago, so i'm not 100% sure what i have done but from my memory:

  1. Due to the fact that dutil only supports harddisk sold by MAI at that time, dutil has to be patched for the drive parameters of the new disk. In the download section is a program for win32 or linux (more a hack) that can patch dutil. The program will convert dutil from motorola s-record format to a binary, ask for the new parameters (tracks, heads, ...) and will write a new dutil in s-record format. Write a new diag tape, this tape will be later used to format the disk.
  2. Install the new harddisk as second harddisk.
  3. Boot from the diag tape, load dutil and format the drive  (command dutil within the loaded dutil will show a menu). Also write a new boot record to the disk
  4. Boot BOSS/IX and create device files for the second harddisk
  5. Create a new partition table with the usb command, the first 2 partitions (boot and swap) have to have the same size as the ones on the source disk (a command refence manual is inthe download section)
  6. Copy the boot and swap partition with debe
  7. make a new filesystem on the 3rd partition (root), mount it and copy all files from the existing root to the new root
  8. The tricky part, BOSS/IX will not start without a config record, i have transferred it with dutil. Dutil can show the config record and also has commands for reading and writing sectors (i dont have the commands in my memory but LIST_COM will show all available commands, i have no documentation for dutil). First read the config record of the new disk (via the dutil menu). Of cause there is no config record yet but you can now see where ths config record has to be stored, note the current values of track, sector and head. Now read the config record of the source disk and write it to the destination disk (at the position noted).


last change December, 15, 2015 Armin. Impressum