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Need help with "unresponsive" Teletek FDC-1C all in one computer-on-a-board.

You're absolutely right. I meant 26, not 16. Which is kinda embarrassing seeing as how I posted the link with the Z80 pinout in the first place. Oh, well, been tired.
patscc
 
At least now I know the CPU is getting the reset signal properly.

The floppies have 110V, and spin, they are getting the -5, +5, and =24V signals to the connectors, and are not totally fried, because they at least disengage the door latch solenoids when I power down.

I don't have any specific reason to suspect the monitor, except a lack of activity on the LED serial tester; they do a bit of a show when I turn the monitor on but that's about it, other than the faint flicker of key presses. When I had local echo on, it would require the computer to be on to give me line feeds. If 'puter was turned on later, then previous keystrokes all appeared at once.

The fact that the screen shows nothing on a reset, (it always gives me a gibberish symbol or two with power on/off), makes me wonder if I have a problem with the "monitor" program, -probably(?), in that EPROM. I know that sounds like I know what I'm talking about, but...

Press on regardless, I always say!
Bruce
 
patscc said:
Does your Fluke have a frequency counter ? What model is it ?
patscc
Click to expand...

Just a VOM with digital display. Now I just learned I ordered the wrong thing for my probe, I must start being more careful.

I shall look again, maybe I can get a much more capable meter, plus freq counter, plus digital logic probe. :stern:

B.
 
USASAgencyman said:
I don't have any specific reason to suspect the monitor, except a lack of activity on the LED serial tester; they do a bit of a show when I turn the monitor on but that's about it, other than the faint flicker of key presses. When I had local echo on, it would require the computer to be on to give me line feeds. If 'puter was turned on later, then previous keystrokes all appeared at once.
Click to expand...
The terminology's a little confusing here; when you say 'monitor' in this context do you mean the terminal?

Disconnect it from the computer and connect pin 2 to pin 3 at the cable end that goes to the computer. With local echo off (full-duplex) and hardware handshaking turned off, what you type should display; when you remove the jumper it should stop. What you describe sounds like hardware handshaking (RTS/CTS) might be enabled.
 
1st point; yes I keep thinking "monitor" instead of terminal and typing the wrong thing.

2nd; Well, I'll be da****! It does echo with 2 and 3 connected. I had tried with the wrong numbering sequence before.

The TERMINAL's cable that came with this computer has caused problems for me and this is one of those times. It is a single, flat cable fed through an empty connector slot on the back panel. At the FDC-1 end, the last six conductors have been cut off, and 20-pin (header type) connector added, the terminal end has the D-25 RS-232 connector. I had been trying to use the numbering system that goes with a 20 pin header, instead of the D-25 numbering scheme. Doh..

Bruce
 
patscc said:
Or pick up a used scope somewhere. Is there anyone you can borrow a scope from ?
patscc
Click to expand...

Finding one to borrow has not gone well.

I'm really wanting to do the used scope thing. I'll start here with this forum, I assume there is a market area., then try to reach out, (stopping well short of Craig's list).

Bruce
 
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The power switch was wired to take power from the main fuse, to the transformer and there are dedicated taps for the board, +16V, -16V, +8V. Another barrier strip has more taps for +24V, +5V, and -5V for the drives. Caveman simple, but if I'd gotten a round Tuit, I would have at least tossed a relay in there for the main 110V.

The motherboard runs a volt and a fraction over, but I'm told that is not unusual, and most boards have their own V.R.s.

Am I missing something important there?

B.
 
patscc said:
No, but I didn't see any mention of it, so I thought I'd better ask. The +-16v and +8v are all present at the Teletek, correct ?
patscc
Click to expand...

Yes, I took the whole thing apart, cleaned it up, took the PSU caps out and tested them, checked voltages everywhere before I put in the Teletek for its very first power-up for me. I even had a new off-white powder coat paint job put on the entire top cover and front panel.

The paint job alone should have made it want to start up...

Bruce
 
A few more questions. On the file FDC-1C007.jpg, there's a bunch of voltages penciled in on the serial ports. Can you measure those ?
Also, have you had the terminal successfully hooked up to anything else before, recently ?
Do you have a PC, or something else with a serial port, either 9 or 25 pin?
patscc
 
patscc said:
A few more questions. On the file FDC-1C007.jpg, there's a bunch of voltages penciled in on the serial ports. Can you measure those ?
Click to expand...
First thing in the morning.
Also, have you had the terminal successfully hooked up to anything else before, recently ?
Click to expand...
No, it came on the brown truck, I was elated to find it had echo once I was brought up to speed on the pin numbering.
Do you have a PC, or something else with a serial port, either 9 or 25 pin?
Click to expand...
Yes, I still use a Compaq with D-9, I need it for programming many remotes with IR codes and macros.

B.
 
Well, here's a thought. We can try to get the terminal talking to the Compaq to see if the terminal works, or try to get the board to talk to the Compaq.
patscc
 
FWIW, here are the voltages, not even close to the notes.

S IO-A and -B have completely identical readings

Connector to terminal removed.

2-20 (even#) -no voltage, ground, or impedance value

3 ---
5 -9.07V
7 ---
9 +9.48
11 + 9.51
13 GND
15 ---
17 ---
19 ---

Terminal cable on voltages coming up.

As for using the laptop, I have to go get it back, it's been loaned out a while.

Bruce
 
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patscc said:
Well, here's a thought. We can try to get the terminal talking to the Compaq to see if the terminal works, or try to get the board to talk to the Compaq.
patscc
Click to expand...
Can't hurt, but if the terminal echoes when 2 & 3 are jumpered and stops when the jumper's removed I think we can assume that it's working. I'd still like to see it echoing through the 1488 & 1489 though, to confirm that they're OK and the cable's wired correctly.

And also whether the CPU's address lines are toggling, i.e. whether the voltages change when it's held in reset state vs. running.
 
S IO-A

Terminal plugged into FDC-1 with 4, 5, 20 connected, (on the FDC-1 header the numbers are 8, 10, which show no values and 13 the ground).

Keyboard press only has an effect on header pin#3, or RS-232 #2

2
4
6
8
10
12
14 +8.34
16
18
20 +9.28


1
3 -8.79 ---- This one drops to something my meter interprets as 0V on keyboard press, RS-232 #2
5 -8.36
7 +8.42
9 +8.53
11 +8.58
13 GND
15
17
19
 
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MikeS said:
Can't hurt, but if the terminal echoes when 2 & 3 are jumpered and stops when the jumper's removed I think we can assume that it's working. I'd still like to see it echoing through the 1488 & 1489 though, to confirm that they're OK and the cable's wired correctly.

And also whether the CPU's address lines are toggling, i.e. whether the voltages change when it's held in reset state vs. running.
Click to expand...

It will be tomorrow, but tell me which pin #s to check on the CPU, I'll list those too.

Gotta run,
B.
 
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