All about NCR and their computers

Some times ago I got in contact with jonhales who is collecting all about the NCR DM-V (decision mate V).

As he lives in England near Cambridge he is also a a volunteer to help with the history of computing.

My history goes 30 years back when I got a DM-V from J­ü­r­g­e­n L­o­h living in W­u­p­p­e­r­t­a­l. At that time my home was near Aachen so it was a short trip to Wuppertal. I don't remember exactly the year but this DM-V works well an had 3 of 5MB external harddisk added. At that time I had enough place for all I was given by friends and other.

Later I got the info that Jürgen has an interesting webpage called Tupel BBS but there is nothing about NCR.

A lot about the DM-V in this forum will be found in German language only so I will try to post understandable in English language.

This is from the past, I have only 5 systems again now. history.htm.pdf

There is a nice serie of videos from Jerry Walker who repairs a NCR DM-V.

As Jerry explains in detail what he does you need time for watching and have patience if you are an expert.

There are 8 videos I believe so please take a look..

https://www.youtube.com/watch?v=-vSIygAAWys&t=32s

Quote from e2k

Es gab auch den NCR Tower 32, hatte 68k prozessoren drin, und lief unter Unix. War ziemlich cool

Interesting but write in English language please as this ist the

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As I'm in contact with jonhales he mailed me some questions I like to post here to get help.

The 80 track floppy format on the DM-V

There are two aspects of the use of the DM-V that I'm still unsure about. One is the use of 80 track disks - when I have tried this with a Gotek, the DM-V doesn't appear to be able to communicate with the disk image, although the definition of the format is adapted from the one I use regularly with 40-track images (it is just the number of tracks that differs, with 9 sectors per track in both formats). I'm aware that I could write some disks and use a floppy drive with 80 tracks. Do you have any advice about what could be preventing my use of 80-track disk images?

[A different topic is that some of the disk images I have seen are 1.2Mb in size - I'm not intending to use these, but again it would be helpful if you have any information about these disk images].

Using a V20 on the DM-V

The other is replacement of the 8088 with a V-20. I'm aware that there is a small file that makes a modification to allow the V-10. I assume this is loaded while the Z80 is in control, in an initial file such as config.sys or autoexec.bat under DOS. Are you able to point towards any documentation of this modification?

Problem with the DM-V keyboard

One of the difficulties I have had with one of the two DM-V keyboards (not the one I purchased from you) was that the 'i' key often needed multiple presses to show the character on screen. I solved this issue by swapping the key mechanism between the 'i' position and F19 and then putting the key-tops in the correct places.

'Tauntek LogICTester' but this is for fritzeflink out of his brain.

Meanwhile, I have ordered a PCB from a Chinese supplier in order to build an example of the 'Tauntek LogICTester'. This is 'old-school' in the sense that it communicates over a serial connection. The advantage with this approach is that it reports on the condition on a 74LS series IC in much more detail than, for example, the Retro Chip Tester Pro. I think this may be helpful in my efforts to understand the operation of the WD1001-05 hard drive controller, as well as more generally in efforts to restore old hardware.

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Hi...

I got parts of a color DM-V and thought I could try to rebuild and test it if it will run. Sadly the mounting brackets for the color crt controller board which requires a larger transformer than the monochrome version are missing. For information - standard switcher and rectifier can be used for controller board flexible disks, keyboard, and I/Fs . The rectifier and switcher for the color CRT are placed on the CRT board.

As the mounting brackets for the crt controller board and a keyboard are missing I will store the parts if some are needed.

My own DM-V is (was) a model with 96tpi floppy drive and a hard disk. I gave the hard disk and the hd-controller away.

As I mostly use CP/M and 80track floppy drives I will use the front cover (for the floppy's) from the color version to add a 2nd floppy drive to my old DM-V.

Now my DM-V has 2 x 80track floppy drives teac fd-55FV-13U. I will make some cosmetic changes as the knobs in front are different named.