Super Olivetti M240

[fmartine]

Hi all, i decided to build a super XT machine, based on one of the best XT pc ever produced ,OLIVETTI M240!
I started from an old basic olivetti m240 machine, at the moment i modified it in this way:

CPU: Nec V30 10 mhz (replace the original Intel 8086 8 mhz)
FLOPPY DRIVE: 2 units, one 1.44 mb 3,5 inches and one 1.2 mb 4,25 inches
HARD DISK: SCSI 8 gbyte
CD-ROM: external box SCSI with PLEXTOR CD-RW 8x
SOUND CARD: Sound Blaster 16
VIDEO CARD: Paradise VGA
MODEM: internal 56k US Robotics
POWER SUPPLY: modified mini atx 450 watt (replace the original AT 200 Watt)

i build also a joystick adapter to use Atari joystick with the analog PC interface, at the moment i'm working to upgrade the video card , do you know wich video card i can use on XT slot (the best one)? I know that ATI Wonder 16 and XL24 are very good and works on it, is it true?

 

[barythrin]

Pretty nice setup. Do you know the differences in the models (M24 vs M240)? I only have the M24 (as an AT&T 6300). lol.. actually I bought it for myself for Christmas and had it on the table from Santa as my wife gave me "the look" and the kids were busy tearing their gifts open. It's a nice remembrance of the steel age of computing.

 

[Old Thrashbarg]

Do you know the differences in the models (M24 vs M240)?

It'd be easier to list the similarities: the case, and the power supply, and the fact that they're both based on the 8086. Here's a site where somebody posted a bunch of pictures of the insides of the M240.

 

[barythrin]

Thanks! That looks like an awesome site too. Something I also wanted to do when I had time (take a bunch of pictures, angles, and descriptions of how to take apart systems). Also found another post which did a bit of describing of differences as well.

 

[sergey]

Nice setup.

One thing looks strange in your specs - Sound Blaster 16. I know that some SB16 cards (especially later Vibra based cards) have 8-bit interface (and use 16-bit part only for IDE port), still it looks like Sound Blaster 2.0 or similar is a better fit

SCSI is a nice touch, especially that it allows connecting external devices (CD-ROM).

I was using Olivetti M24 back in late 80's (it was the first IBM PC-compatible I ever used), and I really liked the build quality. Especially compared to no-name XT/AT clones that flooded the market in the following few years.

Olivetti M24 and M240 are weird beasts. They are and only a few more computers (e.g. Soviet ES1840/ES1841/Iskra 1030, and IBM PS/2 Models 25/30) were based on 8086 processor instead of 8088. Not sure why Olivetti selected 8086 over 8088. Performance improvements could be one reasons, but IMHO much simpler way to increase performance was using faster 8088 or NEC V20. While Intel stopped at 8 MHz, many other manufacturers made 10 MHz 8088, and Siemens even made 12 MHz 8088. NEC V20 were available in up to 16 MHz frequency. In Soviet case I suspect that KR1810VM86 (8086 clone) was available before KR1810VM88 (8088 clone).

Looking at M240 it is interesting that it only provides 8-bit extension bus. I think M24 provided some kind of proprietary 16-bit extension.

 

[fmartine]

M240 is the M24 upgrade, it was sold with 640 kb ram (not 512 like m24), it supports hight density floppy drives, it has a bigger case with more available isa slots, i'll posts pitures as soon as possible

 

[fmartine]

One thing looks strange in your specs - Sound Blaster 16. I know that some SB16 cards (especially later Vibra based cards) have 8-bit interface (and use 16-bit part only for IDE port), still it looks like Sound Blaster 2.0 or similar is a better fit

there's a reson for that choice, i tested it also with a sound blaster pro 2.0 XT ISA board,very occasionally it was freezing ... the problem was caused by the -5v power supply voltage (that kind of boards are very sensible with -5v power supply) . The power supply is not original . it's a modern mini atx power suppply modified to fit inside the old one . I think that the -5 v line was not so stable and powerfull like the AT standard.... so i take a early model of sound blaster 16 isa card, it can be used in an old xt isa slot , it needs only to be configured to use a low dma channel for both hight and low dma. I obtained a more clear sound and a 100% stable system, the games also run little bit fast

 

[fmartine]

Looking at M240 it is interesting that it only provides 8-bit extension bus. I think M24 provided some kind of proprietary 16-bit extension.

boths olivetti m24 and m240 support a special expansion card that can be possible to use ISA AT 16 bit card on it.... it was a very performant PC for that age

 

[archeocomp]

Nice setup.
They are and only a few more computers (e.g. Soviet ES1840/ES1841/Iskra 1030, and IBM PS/2 Models 25/30) were based on 8086 processor instead of 8088.

I collected few more of 8086 based (working) computers. A Victor 86P, two Toshibas T1000LE and a Bondwell B200. They are all portables.

 

[sergey]

very occasionally it was freezing ... the problem was caused by the -5v power supply voltage (that kind of boards are very sensible with -5v power supply)

Can't see how absence or quality of -5V signal would make SB to freeze the system. It is only used to drive operational amplifiers. It can affect the sound quality though...

 

[fmartine]

Here's a picture of an Olivetti M240

 

[fmartine]

Original techs specs was:

Model: M240
Year: 1988
CPU: 8086 8.0 MHz
Operating system: Ms-Dos
RAM: 640.0 kb
ROM: 40.0 kb
Text mode 80 x 25
Graphic mode: EGA 640 x 400 16 colors
Sound: 1 channel internal speaker
Floppy drive: Floppy 5 1/4" 360Kb
Hard Disk: 20 MB Interface st-506

 

[fmartine]

Can't see how absence or quality of -5V signal would make SB to freeze the system. It is only used to drive operational amplifiers. It can affect the sound quality though...

sound blaster pro has internal amplifier for audio output, sound blaster 16 doesn't have it,if the amplifier ask too much current to the -5v line the power supply can also has loss power / voltage oscillation on the others supply line (+12v , -12 v , +5 v), this can cause computer freezing. I read on internet that sound blaster pro isa xt is famous for needs a very good quality -5v line, i also noticed that the computer freezed in the exact moment when sound blaster use digital sound + fm sound (if i test it using only fm sound it never freeze).... it happen only few times, very rare but happens.... with sound blaster 16 no freezing... as i told you before i'm using a modern mini ATX power supply, many of them doesn't provide -5 v, this one do it but it's an economic model, so i think that the quality (also the max power) could not be sufficent

 

[WiZard]

at the moment i'm working to upgrade the video card , do you know wich video card i can use on XT slot (the best one)? I know that ATI Wonder 16 and XL24 are very good and works on it, is it true?

I have an ATI VGA Wonder XL24, can confirm that both the bios and interface can be switched to 8-bit (I have used it in my 8MHz XT Clone). I also have an 16 bit ISA Tseng ET4000 card that works fine on the XT.

 

[vwestlife]

Olivetti M24 and M240 are weird beasts. They are and only a few more computers (e.g. Soviet ES1840/ES1841/Iskra 1030, and IBM PS/2 Models 25/30) were based on 8086 processor instead of 8088. Not sure why Olivetti selected 8086 over 8088.

The Tandy 1000SL, 1000SL/2, and 1000RL, and Epson Equity Ie also used the 8086.

 

[nestor]

The Tandy 1000SL, 1000SL/2, and 1000RL, and Epson Equity Ie also used the 8086.

Also Amstrad used the 8086 in their PCs like the PC1512, PC1640 and other models.

I think the use of the 8086 in PCs was more like a cheap alternative to the 80286 in low end systems.

 

[Jack.]

No.
Olivetti started a new series of PCs with the M240, wich led to the development of M28 (from now on they are all 286 till the M300), M280, M250, M290 and the 386s M300 (M300 without -XX was the last model wich has the old case design like M290) then came M300-XX, M386/M386-XX and M300 XP1.
There was also the M200, with the NEC V40, but it was someway more similar to the M16 than to the M240
The new Olivetti series was meant to be cheap, useful for business/school/home, powerful and reliable. Sure they are not 5-stars rated machines, but they are powerful enough to run Xenix (the support was added with the M28).