• Please review our updated Terms and Rules here

Lanier Model 103 "No Problem" word processor

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Holding the data high on the video dram does nothing other than stop the computer from beeping.

Didn't determine which is the brightness line to the monitor.

Ram on the CPU board has data in and data out with random data that I can capture.

Doesn't appear to be much going on at the keyboard connector but the largest chip on the board is operating because I can get a digital output that changes i/o state with different key presses.

Checked all the voltages actually on the boards after cleaning the power plug.
+4.96
+11.94
-5.01
-12.03

All well within limits and stable.

Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
I'll try removing one of the video DRAM chips and try that, see if I liberate any trash onto the screen.

If not, I'll try draw it out and trace back (forwards?) towards the screen output.

--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Does the solder side schematic show what the connector pads' function are?

I tried removing a DRAM chip (picked an arbitrary one).
Vcc (+5v) to Qout to bring the output stuck "high"
20150409_125434.jpg
Result:

20150409_125540.jpg
Solid tone from loudspeaker. Dialing brightness dial yielded nothing on screen.

Tried putting Qout to ground:
20150409_125455.jpg

Result:
20150409_125540.jpg

Same, constant tone, nothing on screen dialing brightness.

--Phil
 

Attachments

  • 20150409_125356.jpg
    20150409_125356.jpg
    58.8 KB · Views: 1
  • 20150409_125455.jpg
    20150409_125455.jpg
    78.6 KB · Views: 1
  • 20150409_125434.jpg
    20150409_125434.jpg
    70.2 KB · Views: 1
Last edited:

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Also to note, now.. the floppy drive does not pull the head in on the lower drive. It used to, so something's working less than it used to.

--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Monitor plug is as follows:

Ground (notch) something something blank something blank brightness brightness brightness

I'll have to poke at the lines, but I think probably the something on its own is the output- I'll try drive it high with 5v and see what happens.


EDIT:

Ground (notch) h-sync no-response blank v-sync blank brightness brightness brightness

I'm presuming the no response pin is meant to be the output.. possibly something in the monitor is bad. Tried +5v and grounding it and nothing happens. Grounding the H and V sync causes the monitor to lose sync. (obviously).


-Phil
 
Last edited:

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Checked a couple lines- the H and V sync are healthy-
20150409_154541.jpg

Checked the other pins, came to the same conclusions as you did with the pins above (Thank you for looking that up, by the way, this seems to be the same monitor but with less capability, missing the StepScan input but there appears to be everything else, in the order described. It would appear to be a common connector across their range of monitors for this era).

However, I wasn't making good contact with pin 8! I ran a wire from the 5V on the back and hooked in on the board where the connector mates.

20150409_160017.jpg

Powered it up and BLAM, the screen's overdriven bright! (Need to adjust the contrast).

However, there's some screen burn but what looks like |'|'|'|'|'|'|'|'|'|'|'|'| on the screen.. possibly what's meant to be on the screen but the output stage just isn't managing to make it happen.. and back-feeding 5V might just be sinking into the device as it is sinking and then not just a little current. With the brightness turned all the way down:

20150409_160926.jpg

So, video board looks to have an issue between the RAM and the output, as you had suggested earlier.

--Phil
 
Last edited:

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
U5 is a DM74LS10N yes.

U8 #11 -> U5 #8

U5 #9 -> U22 #8 (74LS00N)
U5 #10 -> U23 #10 (74LS08N)

I'm going to probe U8 #11 to see if there's anything coming in there.. if not, I'll ground it and see if the screen goes bright. That'll rule it out as a fault.

If I need to go any deeper on the board I'll have to figure something else out because it's buried in behind the other two cards and it can't go in a different slot. I might be able to get to some of the back of the board though (solder side).

--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
U8 #11 sits high, doing nothing much.

Grounded the pin.

This was the result on the screen, very poor contrast (as you might imagine):

20150410_082748.jpg

So I don't know if the inverter's the cause, or it's further back in the circuit. I can't easily get the oscilloscope probe back much further on the board.
I guess I can solder a flying lead to the pins in question and scope those. That would work. Slow, but it would work.

--Phil
 
Last edited:

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
I can, in this instance, scope those three input pins.

If there's anything sane on them, it should be getting through if the logic is in agreement. If not, I can try driving two high and tapping the third to see if it generates a bright screen.

--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Welp, we have progress, looking at U5 (triple NAND).

Scoped pin 9 on storage mode. Definitely looks like video data, changes every time I capture a screenful.
20150410_154754.jpg

Scoped pin 10. Flatline at zero. (Excuse the blur, it was in long-persistence storage mode).
20150410_154948.jpg

Scoped pin 11. Looks like vertical retrace blank. The curves on the traces are the probe I'm using.. it's seen better days and won't adjust any more.
20150410_155112.jpg

So, out of curiosity, I went ahead and soldered a wire to pin 10.
20150410_160315.jpg

Powered up, poked the wire into the +5v source on the back of the chassis... and leaned round to the front to take a look at the screen...
20150410_160149.jpg

Trash! We like trash! (Even if the same trash comes up upon hitting reset). Character ROM is working, vertical retrace blanking is in time.. overall a nice image, if the contrast isn't a little low.
20150410_160217.jpg

So.. it's alive, but the thing's not getting past initializing the board and turning the screen on.

Progress!


--Phil
 
Last edited:

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Yup, I'm quite happy that I've got a logic-stuck output on the screen. It's at least partly alive :)

Getting somewhere, and having trash on the screen is a nice improvement! (Well, depending on your point of view..)

--Phil

Edit: Looking at it, the implosion shield is cataract but not to the extent of impeding visibility of the screen, and the burn-in isn't so severe as to really generate problems. Good to know though. It would seem the two units are interchangeable however.
The bottom image, close-up of the characters is through the hazy part of the shield, on the area of the screen with the worst burn-in. It's far from noticeable once the screen is displaying an image.
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
I'm inclined to agree; being as it did previously CLICK and engage the r/w head on the lower floppy drive, and now it doesn't- I'm thinking it was getting a little further than it did before.

Could be something as simple as bad RAM.

I'll check the backplane again, I've cleaned the contacts and put some DeOxIt on the lot- that made it considerably easier to seat and remove the cards.

The signals on the CPU board freak out when I put a random (admittedly soft-sector) disk in either drive. The beep from the speaker is interrupted on a regular basis, seems to coincide with the triggering of the sync hole. The signals I poked at randomly on the CPU board seem to be interrupted at the same time.

I'll have to try see where to start from and work back. Least with the video board I had a place to begin from!

--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
I could certainly try that. I just don't have an EEPROM burner any more. I had one that connected to an Acorn microcomputer back in the UK- somewhat moot.

I can definitely rig something up though, I'll take a look more closely at that board Monday.

--Phil
 

Chuck(G)

25k Member
Joined
Jan 11, 2007
Messages
40,258
Location
Pacific Northwest, USA
Is this the Lanier that uses hard-sector 8" floppies, 256-byte sectors backward MMFM? I deciphered a couple of those years back. Sorry, don't have any program disks, just data.
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
I have a PC with both serial and parallel ports available. I rigged up a piece of hardware a while back that could program PIC chips, also. Used the serial port's RTS/CTS lines to program the thing.

Chuck: I think it probably takes the same format, just this one has 5.25" drives.

Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
It's Intel 8080, but same difference for now :)

I need to see, it might pay just to shuffle the RAM chips about for now and see if that liberates any more activity.

I'll see what I can put together. I have a nice big breadboard, can get some chip sockets that can be used to plug in.


--Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Fair enough. I'll leave them where they are then.

I'd seen that the video RAM is the same series, but marked differently and in a CERDIP package. Higher speed stuff for video?

I should hopefully be able to start on it again tomorrow. If I clear some of the kitchen table, I think with the power supply and floppy drives removed it would be light enough to lift by myself safely. That'd give me an easier place to work on it.

Phil
 

PhilipA

Experienced Member
Joined
Aug 4, 2013
Messages
476
Location
Larose, LA, USA
Looking at it, potentially the video RAM chip I had put the voltage to the input and output is on either the right or the left- I'm thinking the right possibly because it's all showing the same character in a tidy rectangle.

Phil
 
Top