M24 and M240: UPDATING AND OPTIMIZATION
v. 0.5.1
of Espers

Index

1. Details and warnings
2. In the little box
3. Cleaning
4. We check
5. We update!
   5.1 Expansion cards
6. OS
7. Software
8. Appendix 1: the M240
9. Appendix 2: future developments and spreadability of this document
10. thanks


1. Qualification and warnings

As written here also applies all'M21 (M24 portable version), all'M24SP (M24 clocked at 10MHz, 640KB of RAM and math coprocessor as standard 8087) and in many cases to any compatible XT .
If you are not accustomed to using soldering iron and screwdriver you should rather let someone else do the upgrade to more experienced than you.
What is written here, I could not test everything personally, so I take responsibility for any damage to you and to your machines.
All mentioned trademarks are belonging to their legitimate owners.


2. In the little box

Let's start with a brief description of the computer before us: the Olivetti M24 is an XT-class computer with Intel processor 8086 at 8MHz and already fitted standard with a serial, one parallel, one for floppy drives, one for the mouse and the system clock (xt many Taiwanese had not standard). The video card can work in high resolution (640x400 way AT & T) or emulation CGA. There may be 1 or 2 floppy, a hard drive with its controller and a minimum of 256KB of RAM. You have probably even your keyboard, perhaps with a DB-9 socket for the mouse close to the connection cable. Importantly, check the presence of the Bus Converter which allows all'M24 to have the 8bit ISA expansion slots otherwise you can not install any expansion unless a proprietary card Olivetti.


3. Cleaning

Let's start with clean (if any were needed) our computer.
We open the M24 by removing the 4 screws on the back and sliding off the covers.
We provide a clean and vacuum all the dust and possibly to remove traces of mold, damp, rust, various kinds of dirt. To do this, there are various products, from CIF cream to toothpaste to degreasers and antioxidants that can be found in hardware (for more information on how to clean a computer from any type of dirt it.comp.retrocomputing see the FAQ).
If the keyboard has some mute button open it, remove the key and clean the contact beneath it with alcohol.
for the monitor screen used liquid glass cleaner or something more specific (do not spray liquid directly on the screen but on a cloth and then use the latter to clean).


4. We check

I recommend you find the diagnostic disc with Olivetti system.exe file that allows you to make a diagnosis of the system.
When the machine tells us what version of ROM mounts and how much RAM owns. With system.exe program or another diagnostic we can see the system configuration.
For Murphy's Law, let's say you are in the worst case: ROM version lower than 1:43, a floppy 360KB, 256KB RAM soldered directly on the card mother.


5. We update!

Disconnect all cables and eventually dismantle expansion cards and disk drives.
We start from the processor: dismantled unsolder the motherboard and the Intel 8086 processor Instead welded a good 40-pin socket and montateci on a NEC processor V30 (eye to mount it on the right side if you want to avoid frying it all!). The NEC UPD 70116-8 (V30 8 MHZ) is a 8086 compatible processor that allows an increase in performance of about 15-40% (depending on the application).
Now if we can put in the math coprocessor socket a 8087 chip 8MHz and set the switch 5 to OFF (if there is no coprocessor the switch 5 should be left to oN).
Check that everything works right through the diagnostic program and then go to the RAM.
If you're unlucky and you have all the RAM or one the two benches soldered directly on the motherboard, you also would agree in this case, Wick everything and assemble the 16-pin sockets in which you will put the chip 256kbit (41256-150 or equivalent).
below we outline the switch for the configuration 0 ram:

DIP-SWITCH 0 (towards the inside of the plate)
4
 3
 2
 1
 Bank 0
 Tour 1
 Plate esp.
 RAM tot.
ON
 ON
 ON
 OFF
 128k
 -
 -
 128k
ON
 ON
 OFF
 ON
 128k
 128k
 -
 256k
ON
 ON
 OFF
 OFF
 128k
 128k
 128k
 384k
ON
 OFF
 ON
 ON
 128k
 128k
 256k
 512k
ON
 OFF
 ON
 OFF
 128k
 128k
 384k
 640k
OFF
 ON
 ON
 ON
 512k
 -
 -
 512k
OFF
 ON
 ON
 OFF
 512k
 128k
 -
 640k

The switch 4 is ON if you use the chips on plate from 64kbit (4164 or the like), OFF when using chips from 256 kbit (41256 or similar).
The switch 6 is ON if you have a 8250 chips OFF if 8530
the switch 7 is not used
the switch 8 is oN if the ROM BIOS is 4k (2732), to OFF if it is 8K (2764)
Let's talk about its ROM. If you have a version earlier than the 1:43 try to update the ROM, this is because the version 1.43 fixes some compatibility troubles and updates the graphics routines to support EGA and VGA modes. The ROM (EPROM) should have an access time of no more than 250ns and I recommend to pay attention to the direction of insertion and not to exchange the ROM H (high byte) with L (low byte) otherwise the M24 will not start.
If the system clock does not keep the date and time it is time to replace the Ni-Cd battery with a new one.
Let's look at the monitor. If you have a monochrome monitor can be connected to ground on pin 2 on DB25 jack Olivetti video card, so you believe to be attached sheet for a color screen and remove the underscore attribute on some color combinations from place to strange horizontal stripes.
If you want you can change the graphics card and monitor with a coupled SVGA: you must enter the new card in one of the Bus Converter slot, screw it and disable the Olivetti card according to the following scheme:

DIP-SWITCH 1 (toward the outside of the plate)
switch
 Description
1
 If ON, floppy drives 40 tracks (48TPI), if OFF 80 tracks (96TPI).
2
 If ON to start slow floppy drives, if off to fast start.
3-4
 Reserved for the hard disk (if it is missing or is the ROM BIOS extension on the disk controller, leave them both OFF).
5-6
 If both OFF, IBM monochrome video emulation, if only 5
ON 80x25 video, if only 6 to ON 40x25 video, if both ON
the "indigenous video deck" :-) and disabled, but you have to extract the 74LS00 located at coordinates 6/7 H and is located and close to the ground screw connector (GND-BLK).
7-8
 If both are OFF, 4 present floppy drive, if both ON 1 unit, if only 7 ON 3 units, if only 8 to ON 2 units.

Now let's see your drives. The M24 has 2 spaces 5.25 "for disk drives, this means that you will have to choose whether to install a hard drive and a floppy drive or two floppy disk drives. The floppy drive may be 5.25" ( 360KB) or 3.5 "(720KB), the discs are usually 20 or 40MB.
to install a 3.5" drive will need a Olivetti frame, ie a converter by measuring 5.25 "to that of 3 , 5. "
At last we see the mouse. If you do not have an Olivetti mouse to stick to the socket on the keyboard (if present) or you can opt for a serial mouse to be attached to the serial port or a mouse with dedicated card or you can adapt a mouse Atari MEGA ST or series to be connected to socket on the keyboard.
Here are below the connector scheme:

CONNECTOR DB-9 MOUSE ATARI ST / OLIVETTI M24
Keyboard connector
Olivetti
 connector Atari
 Signal
5
 1
 xb
4
 2
 Xa
2
 3
 ya
3
 4
 yb
7 <Button Central
 5
 Not connected
9
 6
 left button
1
 7
 + 5V
6
 8
 GND
8
 9
 right button

5.1 Expansion cards

Like all IBM compatible even the M24, thanks to the converter 8-bit XT bus, can install expansion cards of which I quote:
- video card to the VGA and SVGA perhaps
- cards with serial and parallel ports Additional (can coexist up to 4 serial and 2 parallel)
- cards for memory expansion (additional memory will be seen as expanded memory and require the use of dos 4 or above)
- Ethernet cards or Tokenring for connection pC in a local network
- modem card to access the Internet or BBS
- SCSI adapters for the connection of additional equipment and external mass memories
- input cards / output of various nature (D / a converters - a / D, multi I / O for the stepper motor control, etc.) below I will explain the installation, configuration and use of some of these cards.




6. Operating system

The M24 can mount various operating systems and graphical user interfaces and not. The most widely used operating system is MS-DOS because of its reach and compatibility. The minimum version that I would advise you to mount is 3.30 and is also that (in my opinion) best.
Whip later versions of DOS only if the programs used by you require it, since the M24 fails to exploit their best features while in contrast bring more RAM on.
in addition, the version 3.30 is able to fit on a single floppy 720KB or 360KB 2.
If you do not have a copy of MS-DOS you will have cercarvela on abandonware sites on the Internet or via a search engine. I remind you that the MS-DOS is still a proprietary commercial operating system.
As an alternative to DOS you could mount the CPM86 (CPM for Intel processors) or Minix operating system (like Unix) in the XT version.


7. Software


8. Appendix 1: the M240

What has been said here is true in many cases also for the successor M24, the M240. The latter was a 8086 at 10MHz and out already standard with the XT bus (ISA 8bit), 640KB of RAM, the ability to mount the internal controller even at high-density floppy disk drive 1.2 and 1.44MB.
He ran up to 4 floppy drive and could mount an internal hard drive and two external 5.25 ".
the keyboard was different from the M24 and without the connector for the mouse.
the video card was for the first models an AT & T compatible CGA then rode of an EGA series.
she could mount a converter for the XT from 8-bit to 16-bit ISA bus.
the M240 has on the mother plate 2 dip switches (each consisting of 8 microswitches) and 9 jumpers; I report the positions of the switch and jumpers.

DIP SWITCH A (SWA) / OLIVETTI M240
PIN1
 PIN2
 Switch for selection of memory blocks
ON
 ON
 fully disabled memory
ON
 OFF
 256KB
OFF
 ON
 512KB
OFF
 OFF
 640KB
Note: The base modules are available from the factory with 640KB of RAM.

PIN3
 Presence of video control plate EGC
ON
 This
OFF
 Absent

PIN4
 PIN5
 Number of units installed disks (MFDU)
ON
 ON
 1 MFDU
OFF
 ON
 2 MFDU
ON
 OFF
 3 MFDU
OFF
 OFF
 4 MFDU

PIN6
 PIN7
 Type of video screen and the screen size at power
ON
 ON
 OEC plate or EGA compatible video or absent government
OFF
 ON
 40 x 25 color
ON
 OFF
 80 x 25 color
OFF
 OFF
 80 x 25 monochrome

PIN8
 Presence of the math coprocessor 8087
ON
 Absent
OFF
 This

DIP SWITCH B (SWB) / OLIVETTI M240
PIN1
 Installing a floppy disk drive 3.5 "(MFDU)
ON
 3.5 "(720 KB) MFDU Installed
OFF
 3.5 "(1.44 MB) MFDU Installed

PIN2
 Type of floppy disk drive installed as drive A
ON
 5.25 "(360KB which is 1.2 MB)
OFF
 3.5 "(720KB)

PIN3
 Type of floppy disk drive installed as drive B
ON
 5.25 "(360KB which is 1.2 MB)
OFF
 3.5 "(720KB)

PIN4
 Enable / disable video controller Government baseplate
ON
 qualified
OFF
 disabled

PIN5
 Select ROM BIOS to hard disk Government
ON
 Using ROM BIOS on the base plate
OFF
 Using ROM BIOS of government or hard drive not installed

PIN6
 Type Video government installed
ON
 OGC
OFF
 others

PIN7
 Enable / disable the serial interface of the base plate
ON
 enabled
OFF
 disabled

PIN8
 Enable / disable the parallel interface of the base plate
ON
 enabled
OFF
 disabled

JUMPER / OLIVETTI M240
J1 J2
 Enable / disable "Change Disk" signal of the drive A, respectively,
and drive B.
Position 1-2: disabled pe drive 360KB
Position 2-3: enabled drives and 720KB 1.2MB
J3 J5
 Used for production testing
J7 J9
 In normal operation are always inserted
J4
 Used for the calibration of disk drives government of baseplate.
In normal-operation is always inserted.
J6
 Locate the set "burn-in" in production. It is not added to
normal operation
J8
 Disables the ROM BIOS when inserted. normally absent



9. Appendix 2: future developments and spreadability of this document

in the future (although I do not know when) I plan to add sections on the application software, and to improve and expand the description of the upgrades possible, perhaps by extending the article to all XT compatible .
This article may be reproduced in whole or in part, provided that safety is not compromised and that you give about the author and its sources for their work.


10. Acknowledgements

As written here is a set of experiences which I try, the information found on the Internet, through the Olivetti manuals, and in particular on the article "Upgrade fearless: Olivetti M24" published by Giorgio Taramasso Electronics Flash of February 1991. I thank all the friends of it.comp.retrocomputing newsgroups. If you want to contribute to this FAQ, correct errors or simply post comments, please contact me at esper2nonspammarmi@hotmail.com removing the word "nonspammarmi".