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Chromedome45
September 8th, 2015, 07:51 AM
So I am about to pick up another Unix PC 7300. the 1st one I got had an odd green background and from what I have seen of screen images I guess this is normal. However, I never get the welcome screen. My guess is the HD has gone to the great BIT graveyard.

Now my question is if the second one does the same thing how does one open up this thing? Any disassembly instructions anywhere? Also If I replace the HD where
do you find if anywhere the OS for it?

lowen
September 8th, 2015, 08:42 AM
...
Now my question is if the second one does the same thing how does one open up this thing? Any disassembly instructions anywhere?

Yes. http://www.textfiles.com/bitsavers/pdf/att/3b1/ Look in the 'reference_manual' directory for the service docs, and the main directory for install and user docs.


Also If I replace the HD where
do you find if anywhere the OS for it?

http://www.textfiles.com/bitsavers/bits/ATT/unixPC/

You want 3.51, as the devsys is also available there for that version.

Chromedome45
September 8th, 2015, 10:39 AM
When starting this other one up get a odd beep tone and looks like noise on the screen. This is worse than the 1st one I had! See pic screen shot.

Also on the link to the disk Images how can I save them. If I right click it says HTML document. Or save them as html and rename to .IMD?

lowen
September 8th, 2015, 11:10 AM
When starting this other one up get a odd beep tone and looks like noise on the screen. This is worse than the 1st one I had! See pic screen shot.

You'll be needing the reference manual, then.


Also on the link to the disk Images how can I save them. If I right click it says HTML document. Or save them as html and rename to .IMD?

I used 'DownThemAll' in Firefox to download a while back; if I go and left-click on the link today I get an option to download. So the links work for me.

Chuck(G)
September 8th, 2015, 11:35 AM
You can also download things from the command line using wget. If you're going to be using SysV on a Unix PC, it's probably best that you should get used to doing things this way.

Chromedome45
September 8th, 2015, 04:04 PM
Was just a curiosity item Chuck. Wanted to see if they were working. Also the .PDF's I don't see any tear down instructions. So I guess I will have to fudge it.

bear
September 8th, 2015, 06:42 PM
That staggered grid is the result of the built-in system memory diagnostic. If it has extra parts lit (or parts of the grid that aren't lit, or doesn't fill the entire screen -- IIRC it quits drawing the moment it encounters an error) then you have one or more failed RAM chips. It may be that the memory is fine but the next part of the built-in diagnostic is failing. Check the diagnostics manual (the information is on the net) and the colored LEDs along the left hand side of the machine, which will tell you more about what's going on with the diagnostic (which is not completing if that's the screen you see).

It may be just as simple as the power supply low voltage cable harness connectors having oxidized over time so that there is too much voltage drop across the connector, which is a common problem with these machines. It's possible you could bring it back to life for a short time just with a few insertion/removal cycles on that plug, though the plastic is brittle with age now too, so be gentle. The longer term fix is to replace the connector.

billdeg
September 9th, 2015, 06:00 AM
See also
http://unixpc.taronga.com/STORE/

If it helps - how to replace hard drive with ST-251
http://vintagecomputer.net/browse_thread.cfm?id=305

Bill

Chromedome45
September 10th, 2015, 06:54 AM
@Bill thank for that information. Helps a lot. Now has anyone tried to make images of the disks listed in textfiles? I mean these::

http://www.textfiles.com/bitsavers/bits/ATT/unixPC/system_software_3.51/

They are IMD images and seems like IMD chokes on them. So are they 40 track floppy images? Cause what I get is errors on each track or is normal? I don't think so. Also will rawrite work on .IMD?

INFO: I am using an HD 5.25 could that be the problem? works with everything else.

billdeg
September 10th, 2015, 07:13 AM
I used the DOS Co processor card (installed in my AT&T box) to copy the files into AT&T native. I think that's how I did it. Fortunately I have original install OS disks.

I started here and looked for answers:
http://unixpc.taronga.com/

I would think someone would have a process for making OS install disks, or a way to bootstrap a system through the serial port or some crazy thing.

Chromedome45
September 10th, 2015, 07:26 AM
If those .IMD images are out there seems like someone would have made them so you could make the images without errors so as to be useable on the Unix PC. If I get a working MFM drive I will need working disks to recreate the OS.

lowen
September 10th, 2015, 07:34 AM
They are IMD images and seems like IMD chokes on them. So are they 40 track floppy images? Cause what I get is errors on each track or is normal? I don't think so. Also will rawrite work on .IMD?

INFO: I am using an HD 5.25 could that be the problem? works with everything else.

rawrite does not work with IMD. Others on these forums have done this; see http://www.vintage-computer.com/vcforum/showthread.php?44098-Bitsavers-org-UNIX-PC-*-IMD-files-to-floppy-procedure&highlight=unixpc+3.51 and http://www.vintage-computer.com/vcforum/showthread.php?43403-AT-amp-T-Unix-PC-%287300-2B1%29-floppy-reading&highlight=unixpc+3.51 are two I found with a quick search.

Yes, they are 40 track.

billdeg
September 10th, 2015, 07:51 AM
Basically I think you just have to play around with making disks using IMD until it works. I'd assume for your IMD station you need to use a 360K drive, I'd avoid using a HD 5 1/4" to make disks for the UNIX PC.

SomeGuy
September 10th, 2015, 08:28 AM
Those disk images were recorded at 250kbps and ImageDisk always tries to write the image back with the original data rate. When using a low density disk in a 1.2mb drive which spins at 360RPM instead of 300RPM you must tell ImageDisk to translate 250kbps to 300kbps. This will let it write without errors, but due to physical differences between a 1.2mb drive and 360k drive, low density disks written in a 1.2mb drive can not be reliably read in a 360K drive.

So you will still need to get and use a 360K drive.

Chromedome45
September 10th, 2015, 10:59 AM
OK @SomeGuy that makes sense. I will put my 360K Teac back in. The only reason I put a 1.2MB drive was to write images for my Tandy 6000. I will try that and post my results.
Thanks

Chromedome45
September 10th, 2015, 11:18 AM
Ok Put 360k drive back in. That worked fine. Thanks all

Chromedome45
September 10th, 2015, 02:09 PM
OK now for my next question. When the 7300 is powered up without a HD or a floppy drive attached basically a bare bones setup. Beside a green screen with what looks like a type of bitmap repeating and 1 green LED on the motherboard should I see any kind of welcome screen? Almost like a copyright notice at all? I only get the green background. Oh and this is a different 7300 than I Posted a picture of a couple of days back.

Oh and why in the hell did convergent or whoever built this thing solder in the RAM??? Shame on them. Saving a couple of pennies by not using sockets? Taking lessons from apple with the LISA memory boards I guess

Chromedome45
September 10th, 2015, 05:43 PM
So I guess I should have some sort of startup screen. This is what I have: Sorry monitor view is sideways. Is this a RAM problem or what I do not know

bear
September 10th, 2015, 07:38 PM
That would definitely be a problem testing RAM, after which it is halting. From the pattern on the screen, that would be the system memory test (not the video memory test), and based on the repeating pattern, probably a failure of address selection or a data line. The bitmap on the screen is telling you exactly which address or data line has the problem, if you are patient enough to puzzle it out. (Or you could get there a lot faster with a logic analyzer.)

It is not getting as far as trying to boot from any disk drive which may be installed.

Download the 3B1 Hardware Reference manual from the internet. Chapter 3 covers the built-in diagnostic routines and will explain the display and status LEDs.

bear
September 10th, 2015, 07:46 PM
Actually it might be the video memory. I am no longer certain I remember which memory test affects which pattern on the screen in which order. The fact that your diag LEDs indicate test 2 suggest it's the video memory, but I also recall being misled by the LEDs on mine (which ended up having had both main and video memory failures)

Chromedome45
September 11th, 2015, 05:04 AM
@bear and they are all soldered in to boot! Ok I will start with video RAM only 4 chips to clip out and replace. After adding sockets of course! Will use 4416 RAM chips.

Chromedome45
September 11th, 2015, 06:32 AM
Ok I saw chapter 3 and the LED error indications. The other Unix PC had a single amber LED lit no others. That indicates the Map RAM test failure. So if I decide to tackle that PC I have a starting point. AM2149 chips at 19c,20c,21c,22c. Starting to understand the LED error indicators now. So my guess is no LED's lit indicates all is well.

Chromedome45
September 11th, 2015, 12:36 PM
So replace the 4 Video RAM chips now I am getting a pattern of small squares running across the screen and all LED's are lit I am hoping this is normal? I have no idea. Nothing in chapter 3 about all LED's being on.

bear
September 11th, 2015, 12:51 PM
Yep, those squares are the result of searching for a boot block.

BTW ISTR that the LED 4 "map RAM" was my red herring, and what my problem actually was was a failed DRAM in the main system memory. What is on the screen when you get this failure?

Chromedome45
September 11th, 2015, 01:20 PM
Well I got it to boot up! Floppy controller chip needed to be reseated and the Included TEAC is messed up. I never got that failure only the number 2 LED. I wound up replaced the video RAM. All 4 chips and of course always the last chip you replace fixes it.

Maverick1978
September 11th, 2015, 01:23 PM
Nice work!

Now I gotta see it working in person :)

Chromedome45
September 11th, 2015, 02:51 PM
C'mon over !

Chromedome45
September 15th, 2015, 01:45 PM
Ok now that I got a working floppy and hard drive in the 7300 I installed Unix 3.51. All is well with the installation but I have another hardware problem. The mouse pointer is stuck in the upper left hand corner. And does not move. I have cleaned the rollers, taken it about to check for voltages on the encoder chip. All seems and looks ok. Any one have clues?

Also I thought this was GUI version of Unix? When logging in it's in text mode and all commands seem to be text. I did notice in the upper right hand corner a "W". Does that put it in Graphical mode? Or do only apps run in Graphical mode? Or am I way off base and expecting to much?

billdeg
September 15th, 2015, 01:59 PM
There are guides online, in addition to my web site, for how to access the GUI, what usernames and passwords work by default, etc.

http://vintagecomputer.net/browse_thread.cfm?id=168

Bill

Chromedome45
September 15th, 2015, 02:09 PM
So I was reading the Owners Manual and it mentions the Office? I guess it is the GUI frontend. Where can I get this software or was it load as part of the 12 disk 3.51 install disks? And if it's there how do you run it?

@Bill I don't see any command on your site to get to the GUI. Or I am going blind.

billdeg
September 15th, 2015, 02:33 PM
Frank - log in as "office" should take you to GUI automatically. Let me know how it goes. I have a band practice in a few, I may not be able to reply as quickly.

Chromedome45
September 15th, 2015, 02:35 PM
Ok I will try that. And will advise

Chromedome45
September 15th, 2015, 03:23 PM
Office wants a password. Do you know what it is?

Chromedome45
September 15th, 2015, 05:33 PM
Mouse still not working right. Possible to use a PC Serial mouse with some re-wiring?

Chromedome45
September 20th, 2015, 06:40 AM
Ok I found another UNIX pc mouse and the GUI is working when I use install at the user log in. Also discovered that if I create my own user name it will automatically go to the GUI. I guess everyone knew that except me. Now to re-learn UNIX. I used to know how to use it to some degree.