TS1000 error code 2 keeps happening

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mrtinb
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Re: TS1000 error code 2 keeps happening

Post by mrtinb »

The best tool to convert Wave to P-file is Java ZX81 Tape Converter.

That's the program I've used to get programs off old tapes.

It's a little difficult to setup the default values. But you can correct all data bit by bit. And you can always see if the listing looks ok.
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

mrtinb wrote: Fri May 29, 2020 3:20 pm The best tool to convert Wave to P-file is Java ZX81 Tape Converter.

That's the program I've used to get programs off old tapes.

It's a little difficult to setup the default values. But you can correct all data bit by bit. And you can always see if the listing looks ok.
I tried using it but if you don't know what the source is supposed to look like it seems impossible to use. Now that I have the actual listing it'd be probably quicker using tesseract on screen shots and modifying its output :-/
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

XavSnap wrote: Thu May 28, 2020 3:42 pm

Code: Select all

9991 PRINT PEEK 16388+256*PEEK 16389-PEEK 16413;"  RAM"
9992 PRINT PEEK 16412+256*PEEK 16413;"  END STACK"
9993 PRINT PEEK 16396+256*PEEK 16397-16509;"  PROG.LENGHT."
9999 PRINT PEEK 16388+256*PEEK 16389-PEEK 16400-256*PEEK 16401;"   STACK"
I think you forgot to divide by 2 since RAM size was 32K for a 16K configuration.

One other question. I have, as a first line of code, a REM statement with inverted characters. Works fine on a TS1000, ZX81, and in EightyOne, but when I save it as a .p file the inverted characters disappear in the REM and if I put them back in the text file and convert via zxtext2p.exe it complains about them (Non-mappable character in input). What is going on? Both p2text.exe and zxtools.exe strip the inverted markings out of the first line.
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

So I figured out the memory problem with my 16K RAM pack. A resistor had broken off that was squeezed in near the ribbon cable. When you took it out of the case it made contact but when you put it back in it lost contact.

I'm still trying to figure out why my LCD TV starts glitching at the top 4 lines when the RAM pack is in the case vs not in the case (it doesn't happen immediately but after 5 or so minutes of being in the case -- could it be heat???). It's a US model so the inside is painted in conductive metal and there is a metal clip on the circuit board that makes contact with it (I taped it up but no difference). When I apply pressure to the back of the RAM pack via rubber bands, to simulate the back of the case closed I don't get the glitch, but once the back case is on, eventually it starts to glitch. There is cardboard to protect any shorts and there is no metal contacts near the edges so I don't think it is shorting.

Maybe it's pressure on some component (capacitor maybe) that's causing it and it requires it in some specific way. I will next re-solder all those joints to see if it makes a difference. When hooked to another TV simultaneously the other TV doesn't glitch while the LCD does (and the other TV can be LCD or CRT). The fact that I can somehow control it means that this LCD TV might be showing issues with the RAM pack that other TV's aren't (i.e. if it were to glitch all the time on that LCD then I'd say it's not the RAM pack).

Here are the before and after pictures:
Before.jpg
After.jpg
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

So the video glitch is heat related. When the RAM pack's rear circuit board is not in the enclosure the LCD TV does not glitch. I tested it with a hair dryer and the back of the circuit board out of the enclosure, and after a few seconds the screen glitches, then when you take the hair dryer away and blow cooler air on it after a few more seconds it gets back to normal. Rinse and repeat with same effect.

So question, does that mean a failing memory chip or capacitor? Or is it just a loose solder joint that expands? I don't get memory faults but this particular LCD TV has the top 4 lines jitter to the left about 3 columns and back over and over again with this repeated occurrences whereas others haven't exhibited it as of yet. I suppose I could 3-D print a back panel with vents in it. The front half of the board is enclosed in the front half of the case (also interior metal paint) and doesn't cause a problems...both sides have IC's on them with the back side hosting the ITT 8234/35/36's.
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1024MAK
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Re: TS1000 error code 2 keeps happening

Post by 1024MAK »

I suspect timing. Most of the capacitors are there for decoupling the various power rails, it’s unlikely any of these would cause the problem.

However, I can’t explain why it affects one TV, but not another.

Mark
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

Whatever the issue, it is heat related with the rear circuit board. I re-soldered everything on the rear board and it still does it. It has 4 electrolytic capacitors and the rest are all ceramic. I suppose I could try and replace the four though they look good and I've read that early 80's capacitors tended to be higher quality and last longer. If I leave the back case on and take the front case off, freeing it to the air, it still does it, but not vice-versa, so it's the rear board.

I wonder if I stick heat sinks on all chips on the rear circuit board, if that would help? It's in an enclosed space with about 1/2" to 3/4" gap between chips on rear vs front. There are two tiny notches at the top and bottom for airflow (as well as where the connector is comes out).
Last edited by bwinkel67 on Sat Jun 13, 2020 10:59 pm, edited 1 time in total.
bwinkel67
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Re: TS1000 error code 2 keeps happening

Post by bwinkel67 »

...though, thinking about it, how does extra hit impact electrolytic capacitors...they either work or not, correct?
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1024MAK
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Re: TS1000 error code 2 keeps happening

Post by 1024MAK »

On the issue 1 RAM pack boards, there are only two capacitors associated with control signal timing. Both of these are mounted on the logic board near the 74LS32 logic chip. Both these capacitors are disk ceramic types, one is 33pF and one is 47pF. Associated with these are two 330 ohm resistors. Again, these are mounted on the logic board near the 74LS32 logic chip.

None of the electrolytic capacitors or any of the other ceramic capacitors will affect the timing. But it is wise to confirm the the +12V and the -5V supplies to the 4116 RAM chips are present and within specification (+/-10%). Pin outs are linked in my sig. The electrolytic capacitors in this unit are used to generate and smooth the +12V and the -5V power rails.

Mark
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1024MAK
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Re: TS1000 error code 2 keeps happening

Post by 1024MAK »

bwinkel67 wrote: Sat Jun 13, 2020 10:58 pm ...though, thinking about it, how does extra hit impact electrolytic capacitors...they either work or not, correct?
They are affected by heat and cold. Temperature extremes affect their capacity. As does age. High temperature tends to age them faster than they otherwise would (the liquid electrolyte ‘drys up’) and they lose capacity. That then makes them even more sensitive to temperature. However, often once the circuit they are in starts working, they often work well enough that they appear to be okay.

If there is any doubt (supplies out of specification or excessive ripple voltage), renew them. Use the same capacitance rating, the same voltage rating (or a higher voltage rating) and preferably use 105°C types.

Mark
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