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The definition of insanity...

clh333

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Feb 22, 2015
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Location
Cleveland, OH, USA
... is doing the same thing over and over and expecting different results. Undeterred, I have acquired another AT&T machine, having bricked two others.

Physically this resembles my 6312 WGS but with subtle differences: It lacks the "AT&T 6312 WGS" logo and it lacks two ID plaques normally found on the bottom of the case; someone has removed them at some time: four holes remain.

The machine bears a "Property of NCR" sticker and an inventory barcode sticker. It has two 5.25 drives and an 18 Mb HD.

The machine POSTs and boots to DOS 4.x, a bare-bones installation probably the result of wiping the HD; just DOS and a "MONODEMO" directory; a FILES= statement in CONFIG.SYS and a PATH and PROMPT statement in the AUTOEXEC.BAT. Even the DOS HELPDIR is missing. The BIOS ROM credits Microsoft, AT&T and Phoenix "compatibility" software. The POST notes a problem with the floppy disk configuration and recommends running "SETUP". I know that disk exists somewhere in the universe but I haven't found it yet. I got it once before from the AT&T site; I should have a floppy of it somewhere.

The CMOS battery had some juice left but the date and time were back in the '80s. I noticed that the RTC has trouble with Y2K. More troubling, and part of the reason for this post, is the screen update. I am running this machine, which did not come with a monitor, on my AT&T CRT318H. I have used the monitor with other machines (prior to an unfortunate attempt to fit an XT-IDE in the WGS) but with this machine I notice that when the screen scrolls, as the result of a DIR command, for example, the top half of the screen displays an interlace (blank lines) while it is scrolling. When scrolling stops the screen is stable and complete. At all times the bottom half of the screen display is non-interlaced, so I'm wondering if this indicates a problem with the display controller or some other circuitry in the machine. Alternately it could be a problem with the monitor, which hasn't been powered up for a year.

I have another, proven, monochrome AT&T monitor and another untested 318H that has seen better days, but I am reluctant to risk any more equipment until I have an idea of what I'm trying to accomplish. So:

Any suggestions on how to proceed? Thanks.

-CH-
 
Back in limbo:

For whatever reason the machine was able to hold its configuration - or what was left of it - with a Sanyo 6VDC back up battery holding less than 1V of power. But the POST complained about battery voltage and about the two floppy disks' configuration, so I attempted to recharge the backup battery before running the configuration routine, which has to be run from a special disk, a 5.25 720k containing a machine-specific DOS boot. When I removed the battery to charge it the machine reverted to 40 column display and forgot about the hard drive. Since then I have been unable to run the configuration utility and there I sit.

The machine has a 1.2Mb Toshiba FDD6881 5.25 as Drive A: and a 360K Panasonic JU-455 5.25 as Drive B. The HD is an MFM NEC D5126H, nominally 20 Mb, driven by a WDC controller. I have verified that my configuration diskette is viable and that each of the two floppies are functional (using the SuperCard Pro to verify track access and rotational speed) but the BIOS will not boot the configuration disk. Or any other OS disk, either.

It may be that one of the components has failed but it may also be that a jumper setting is wrong. What I do not have, however, is any documentation on setup or troubleshooting of this machine, which I believe is a PC 6312, perhaps WGS. If anyone has or knows the location of such documentation, please advise.

Thanks,
-CH-
 
Found some info at the following site: https://www.ardent-tool.com/Olivetti/Docs/service_guide/systems1.html. The relevant file is cap4.pdf which details the Olivetti M280, which is the equivalent of the AT&T PC 6312. My system board turns out to be a BA817 (earlier, later version is 824) with ROM version 2.16, which, thankfully, can recognize a 1.4 Mb 3.5" FD as well as discriminating between different densities of 5.25" drives. A board diagram shows key locations and tables of jumper settings are also included.

No troubleshooting or maintenance info but more than I had.

-CH-
 
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