PDA

View Full Version : Olivetti M20



Dwight Elvey
April 7th, 2008, 09:06 PM
Hi All
How many on this list have Olivetti M20's. ( not M24's )?
I'm wondering if there is anyone with a 8086 card for the M20.
Actually, I think there was a Z8000 cards for the M24 but
I think that would be really rare.
If there is another M20 owner, are you aware of Davide Bucci's
site?
Dwight

Dwight Elvey
April 9th, 2008, 07:10 AM
Hi All
This is a tough group. I'd thought there might be at least one other
M20 owner.
The M20 should be on most anyone's "want list". It was the only personal
computer with a Z8000 processor. These machines are easier to find
in Europe but they do turn up every now and then in the US.
It looks like it might be any one of a number of PCs of that time frame
but is really quite rare. Running a Z8000 is a nice change from running
the various 8088/86 machines.
Should anyone find one, I can help get it up and running with software.
Dwight

Druid6900
April 9th, 2008, 11:45 AM
I only have one Olivetti and, if I'm not mistaken, it's an M25 (386?).

However, if I ever get a 20, I'll let you know and we can talk about it.

fjkraan
April 14th, 2008, 08:59 AM
The M20 is Z8000 based and runs PCos (an Olivetti OS) and CP/M 8K. There were versions with two floppy drives (40Tr, SS, SD) and with a harddisk (10-20 MByte?). Standard quite high resolution graphics for the day, color board an option. The PCos version had a proper MS-Basic which supported the graphics card.
I had one once, but traded it long ago. Very limited documentation available.
There were some slots in the machine, but I never heard about an 8086 option. The M24 had a special slot for a Z8000 card (to run the PCos system).

Dwight Elvey
April 14th, 2008, 12:05 PM
The M20 is Z8000 based and runs PCos (an Olivetti OS) and CP/M 8K. There were versions with two floppy drives (40Tr, SS, SD) and with a harddisk (10-20 MByte?). Standard quite high resolution graphics for the day, color board an option. The PCos version had a proper MS-Basic which supported the graphics card.
I had one once, but traded it long ago. Very limited documentation available.
There were some slots in the machine, but I never heard about an 8086 option. The M24 had a special slot for a Z8000 card (to run the PCos system).

Hi
It could have a 11Meg hard disk. There were two floppy options both were 35 track. One was 320K
disk the other was 640K disk. If the hard disk was mounted in the machine, you only could
have 1 floppy drive.
The machines with the 640K disk had firmware for the hard drive in ROM but the 320K needed
to boot to the floppy first before recognizing the hard drive.
I've adapted my machine to handle a ST251. It did require some software changes because
of step rate issues. I mounted my HD external and kept both floppies.
With the 8086 card, it could boot to the Olivetti version of DOS for the M20. It was mostly
compatible.
Dwight

peterbe
May 23rd, 2008, 09:29 PM
Hi All
How many on this list have Olivetti M20's. ( not M24's )?
I'm wondering if there is anyone with a 8086 card for the M20.
Actually, I think there was a Z8000 cards for the M24 but
I think that would be really rare.
If there is another M20 owner, are you aware of Davide Bucci's
site?
Dwight
I used to have an Olivetti M20, which was given to me at Olivetti Advanced Technology Center in Cupertino, California in the early 1980s. I was project lead in developing an OS for the machine. There WAS an 8086 board for the machine, designed by a company in Cleveland (I think it was Tecmar). I wrote part of a RAM BIOS extension for emulating IBM-PC text graphics etc. that wasn't supported by Tecmar's ROM BIOS.

I gave the M20 (WITH the 8086 board) to a friend in San Francisco several years ago. He thinks it's still in his basement. We'll search for it later in the weekend.

This machine was originally going to be named M16, but we (in California) had to tell the Italians that was a US military weapon, so they changed the name to M20.

The Z8000 memory management on this machine was very poorly implemented, that's another story!

The M24 was completely an 8086 machine. There were some minor problems with it due to the fact that the IBM PC was an 8088 machine, and there was a mistake in the M24 in handling byte I/0 instructions - that was a problem for Microsoft display drivers for Windows.

Dwight Elvey
June 27th, 2008, 09:17 PM
I used to have an Olivetti M20, which was given to me at Olivetti Advanced Technology Center in Cupertino, California in the early 1980s. I was project lead in developing an OS for the machine. There WAS an 8086 board for the machine, designed by a company in Cleveland (I think it was Tecmar). I wrote part of a RAM BIOS extension for emulating IBM-PC text graphics etc. that wasn't supported by Tecmar's ROM BIOS.

I gave the M20 (WITH the 8086 board) to a friend in San Francisco several years ago. He thinks it's still in his basement. We'll search for it later in the weekend.

This machine was originally going to be named M16, but we (in California) had to tell the Italians that was a US military weapon, so they changed the name to M20.

The Z8000 memory management on this machine was very poorly implemented, that's another story!

The M24 was completely an 8086 machine. There were some minor problems with it due to the fact that the IBM PC was an 8088 machine, and there was a mistake in the M24 in handling byte I/0 instructions - that was a problem for Microsoft display drivers for Windows.

Hi Peter
I missed your post. I have two M20's now but would love to have one of the 8086
boards.
They also made a typewriter that was called a M20.
I've made maps of the memory management ROMs. They should have used
the memory management chip but then one would have needed to decode
the BOIS ROMs. I was wondering, why did they only dual mapped one segement
and then just set the remaining as the same for both code and data?
Also, why was the assembler only good for non-segemented code?
Dwight

Raddit123
March 8th, 2016, 03:20 AM
Hi all,

I know this is an ancient thread, just thought I'd throw in that I have a m20. One with dual floppys. Does any one know where I can get a boot disk?

Cheers :)

olivetti
October 3rd, 2016, 01:59 AM
Hi,

i do have an M20 with the APB8086 Card installed and functional. Also, i do have an M24 with the GO330 Card (Z8001 CPU) to run PCOS on it.

daver2
October 3rd, 2016, 10:58 AM
Raddit123,

I assume you have found the site Dwight mentioned in the very first post at http://www.z80ne.com/m20/index.php. Here you will find utilities (some of which Dwight wrote I understand) to transfer images/files to from an M20 disk on a PC. There are also some software downloads on the website.

I never actually owned an M20 - but was building a Z8001 homebrew system based upon it at the time. Of course (like most projects) that never got finished... But I still have the parts and the inclination when I retire (busy with C= and DEC projects at the moment)... I thought the Z8K was a very nice device. I find the source code also interesting for CPM8K.

Dave

Raddit123
October 7th, 2016, 09:15 AM
Hi daver2, I've got the boot disk sorted, another member (chris-uk) lent me some to make a copy of. I need to sort a few issues with my device out (keyboard/floppy) and then we should be good to go :) I'm guessing these are rare machines seeing as only a few of us on here own one. I was lucky enough to be given mine, but I was wondering if they have any value to them? (not that I'd sell mine!)

daver2
October 7th, 2016, 09:30 AM
Excellent news Raddit123 - well done Chris.

Not too many of these machines around to my knowledge - I guess most of them are in people's lofts/barns/etc. in Italy?

Value - depends who you talk to of course. If you ask my wife - there is absolutely no value at all in any of these things :-)...

Dave

Dwight Elvey
October 7th, 2016, 10:23 AM
Most that are sold on ebay don't get what
one would expect.
I think part is that people confuse these with
the M24.
If more realized that this series of Olivetti's were
one of the few Z8000 processor machines created,
it might see higher value.
Rare is not always equal to valuable.
Dwight

Raddit123
October 11th, 2016, 09:56 AM
Fair enough, I quite like them anyway... So I've managed to get it to boot using the disks I have. My issues are that this involved using a new floppy cable and none of the ones I own will reach far enough to be able to use both drives (though it is mm out). Also I've discovered most of my keys don't work, I'm considering taking the keyboard apart for a clean. There is some dampening foam behind the PCB, I'm guessing this has perished, does any one know if this is important?

daver2
October 11th, 2016, 12:05 PM
You can buy the ribbon cable connectors and cable and make your own disk cables up to the correct length.

I have a load of ribbon cable here - your more than welcome to some if that helps?

Dave

Dwight Elvey
October 11th, 2016, 01:20 PM
I've had my keyboards apart but don't recall any foam.
It has been a long time.
There is a metal cricket like piece that pops down to make
contact across two traces. I suspect it is an oxide problem but
my experience was that the problem comes back after cleaning.
I've not tried de-ox or DC#4 yet.
I often just keep tapping the key until it works.
I don't have quick access to my machines, as they are in storage
right now.
Dwight

Raddit123
October 15th, 2016, 07:52 AM
I'm going to try and get round to it this weekend, I'll let you know how it goes!

Raddit123
October 19th, 2016, 12:53 PM
This post is mainly for Daver2's benefit as it has pics of the floppy cable/drives that came out of the machine, but others may find it useful as well so I'll put it here. (there's also a CPU pic for your enjoyment).

Motherboard port to 1st floppy drive connector aprox. 125mm
1st floppy drive connector to 2nd connector aprox. 300mm.

Note - this does build in a little slack. (a few mm)

Images:

33920339213392233923339243392533926339273392833929 339303393133932

daver2
October 19th, 2016, 03:12 PM
Excellent photographs.

Do you want to have a go at making the cable yourself? All you need is a pair of decent wire cutters and a small bench vice.

You can purchase the disk drive 34 way edge connectors from here: http://www.ebay.co.uk/itm/34-WAY-EDGE-CARD-TO-IDC-CONNECTOR-0-1-PITCH-2-54mm-TWO-PIECES-/291575854601?hash=item43e3467609:g:klsAAOxybetSC~t F (for 2 off) or here: http://www.ebay.co.uk/itm/5-x-34-way-IDC-card-edge-connector-Fujitsu-FCN-767J034-AU-1-2-x-17-34-pin-/401202546368?hash=item5d698906c0:g:s34AAOSwH6lXRMz 8 (5 off).

You can purchase the motherboard connector from here: http://www.ebay.co.uk/itm/Floppy-ribbon-cable-IDC-connector-34-way-Amphenol-/121360582279?hash=item1c41a78687:g:984AAOxykmZTLYX Z (1 off).

All companies are in the UK.

I will quite happily send you a lump of ribbon cable for the cost of the postage and packing.

There is a video demonstrating how to make the cable to connector joint (https://www.raspberrypi.org/blog/make-your-own-ribbon-cable-with-gert/) - and I can provide you with some tips and does and don'ts before you start. For example, I would use a couple of thin wooden packing between the metal jaws of the vice and the plastic of the connector...

How would you feel about doing that rather than me make it up? It may help you with a new skill...

Dave

Raddit123
October 20th, 2016, 10:09 AM
Cheers Dave,

That would be great :) if you PM some details.

daver2
October 20th, 2016, 11:51 AM
If you PM me with your full name and address I will put some cable in the post 'free-gratis'

I will send you a PM shortly (within the next couple of days that is) with some 'gotchas' to avoid.

Dave

pevalcas
February 8th, 2017, 03:53 PM
Hello Dwight,

I have two Z8000 boards for M24 and I believe at least 10 or 12 8086 boards for the M20.

As I wrote, I have around 35 M20 of different types.

I also have one with the very rare color monitor, the rare GO220 IEE488 card and GO246 multi communication card.

Regards, Vincenzo.

pevalcas
February 8th, 2017, 03:55 PM
Hello there,

are you Italian? Where do you live? I'm close to Milano.

Regards, Vincenzo.