VOGONS

Search

Common searches

[SOLVED] Olivetti M240 dead battery?

Topic actions

First post, by devius

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

I'm restoring an old Olivetti M240 I acquired last Summer. It's coming along nicely and it's looking very good indeed, but there is one issue that bothers me. The original battery had leaked, obviously. I replaced it with an identical one bought about 1 year ago:

IMG_4976.JPG
Filename
IMG_4976.JPG
File size
187.83 KiB
Views
686 views
File comment
Olivetti M240 battery and speaker board.
File license
Fair use/fair dealing exception

The problem is that date and time aren't saved when I shutdown the PC. I have installed MS-DOS 5.0 and I have set the date and time and verified it stays correctly defined for as long as the PC is powered on.

All the other functions of that board pictured above seem to be working correctly, but I'm not sure if there is something wrong with the battery, or if it's normal that the PC doesn't save the date and time. It's my first time using a PC from before 1994 extensively. Can anybody shed some light in this matter or suggest ways to debug this issue?

Last edited by devius on 2017-04-23, 19:16. Edited 1 time in total.

Reply 1 of 3, by dieymir

Posted on 
User metadata
Rank Newbie
Rank
Newbie

I'm not an expert in old Olivettis, but the M240 is an improved version of the M24 (aka AT&T 6300) and so it's and XT clone ... the RTC was a new feature of the IBM AT, the IBM XT does not have a RTC.

What this means is that your M240 has a _non-standard_ RTC and you need a specific utility or a specific OEM DOS version (older than 3.3, see the note) to get/set the time & date. Maybe the utilty of the M24 works, check these pages:

https://sites.google.com/site/att6300shrine/Home/downloads
http://www.vcfed.org/forum/showthread.php?535 … -6300-Assembler

Olivetti MS-DOS 3.2 is here:
http://old-dos.ru/dl.php?id=10858

or here (italian):
http://www.ti99iuc.it/web/_upload/image/PC1-O … OS322-GW-LR.zip

Hope this helps.

NOTE: M$ included the source code for the CLOCK$ device driver in DOS versions prior to 3.3 so some OEMs (maybe Olivetti too) modified its own DOS OEM versions to make the date/time commands get/set their propietary RTCs. Ffrom 3.3 this isn't possible since the OAK does not supply the source code for the CLOCK$ driver and you *must* have either an AT compatible RTC, a driver or a specific utility to do that.

Reply 2 of 3, by devius

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie

Thanks. I didn't knew it could be a non-standard RTC, but your explanation makes sense.

The strange thing is that while the computer is running the standard DOS date command is able to set the date, but that's probably just a software thing.

Reply 3 of 3, by devius

Posted on 
User metadata
Rank Oldbie
Rank
Oldbie
dieymir wrote:

I'm not an expert in old Olivettis, but the M240 is an improved version of the M24 (aka AT&T 6300) and so it's and XT clone ...

In the mean time I found out that the M240 was rebranded and sold by AT&T as the 6300 WGS.

dieymir wrote:

https://sites.google.com/site/att6300shrine/Home/downloads

The page this links to contains a CLOCKFIX.ZIP file that has a clock driver for the 6300 family's RTC that seems to work perfectly fine on my M240. That did it! Best of all it only uses 288 bytes of RAM 😀 Many thanks for your help and guidance!

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window