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Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 25 May 2023 22:33
by rubber_jonnie
Icky wrote: 25 May 2023 22:19
PhilC wrote: 25 May 2023 07:51
@JezC i don’t think @Icky has anything to worry about with my old engineers hands.
My thumb has been in the wars recently. The new puppy has been at it.
Icky got an owie :(
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 02 Jun 2023 14:51
by PhilC
Annoyingly, the TI-99 that I'd fitted the new ram and rom chip to decided it was going to play up. When left running for a couple of minutes the screen would start getting corrupted and then lose sync.
So one of my Chinese spare parts arrived today, I ordered a new TMS9929ANL chip and thought I'd test it on the dodgy TI. Well the good news unexpectedly is that fitting that actually cured the issue with the TI.
So one very simple
10 LET P = 1
20 PRINT P
30 LET P=P+1
40 GOTO 20
and its still running just fine but boy is it slow, we're only up to 4119ish at time of writing. I can't remember these computers seeming this slow back in the day? :lol:
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 02 Jun 2023 14:54
by rubber_jonnie
PhilC wrote: 02 Jun 2023 14:51
Annoyingly, the TI-99 that I'd fitted the new ram and rom chip to decided it was going to play up. When left running for a couple of minutes the screen would start getting corrupted and then lose sync.
So one of my Chinese spare parts arrived today, I ordered a new TMS9929ANL chip and thought I'd test it on the dodgy TI. Well the good news unexpectedly is that fitting that actually cured the issue with the TI.
So one very simple
10 LET P = 1
20 PRINT P
30 LET P=P+1
40 GOTO 20
and its still running just fine but boy is it slow, we're only up to 4119ish at time of writing. I can't remember these computers seeming this slow back in the day? :lol:
What have you got against for/next loops ;)
Glad to hear it's working :)
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 15:05
by PhilC
This arrived in the post today, thank you @mrbombermilzy
IMG_2723.jpeg
As you can tell I have all my tools to hand to take it apart and get it working again. But if that doesn’t work I have a pair of 36” stilsons and a large axe in the shed for those stubborn case screws.
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 15:14
by PhilC
First plug in and
IMG_2724.jpeg
Hoping it’s something simple like a memory error but we will soon see once I open it up.
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 15:43
by PhilC
So I plugged the electron in, got the Scope ready, logged off from my work pc and BEEP, I about jumped off my chair.
It will now boot to desktop but takes a very long time about it, so I think I shall be checking the reset circuit first. PSU seems ok at 4.96V and -5.02V.
Edit:
Whoops, if you plug the keyboard in it now boots right away, time to leave it off for a mo but still check the reset caps. Only other thing I've done is to check and clean the ULA.
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 16:08
by PhilC
And it won’t go wrong at all now, well that was disappointing, I was hoping for more of a challenge.
It does look lovely and clean inside too, so now I’m off to try and find a tape lead for it.
IMG_2726.jpeg
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 16:09
by rubber_jonnie
PhilC wrote: 09 Jun 2023 15:43
So I plugged the electron in, got the Scope ready, logged off from my work pc and BEEP, I about jumped off my chair.
It will now boot to desktop but takes a very long time about it, so I think I shall be checking the reset circuit first. PSU seems ok at 4.96V and -5.02V.
Edit:
Whoops, if you plug the keyboard in it now boots right away, time to leave it off for a mo but still check the reset caps. Only other thing I've done is to check and clean the ULA.
Is that wrench for percussive maintenance?
I would have a look at the electrolytic caps in the internal part of the PSU, obviously there's not much to be done with the external AC part of the PSU. Mine were a mess and had to be replaced.
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 16:10
by PhilC
rubber_jonnie wrote: 09 Jun 2023 16:09
PhilC wrote: 09 Jun 2023 15:43
So I plugged the electron in, got the Scope ready, logged off from my work pc and BEEP, I about jumped off my chair.
It will now boot to desktop but takes a very long time about it, so I think I shall be checking the reset circuit first. PSU seems ok at 4.96V and -5.02V.
Edit:
Whoops, if you plug the keyboard in it now boots right away, time to leave it off for a mo but still check the reset caps. Only other thing I've done is to check and clean the ULA.
Is that wrench for percussive maintenance?
I would have a look at the electrolytic caps in the internal part of the PSU, obviously there's not much to be done with the external AC part of the PSU. Mine were a mess and had to be replaced.
Yes, whenever you can't find a hammer, use your Ridgid Stilsons, larger bang, the bigger the pair. This only needed a little tweak, so that 18s came out :lol:
Re: PhilCs blog / the latest things hes broken(fixed)
Posted: 09 Jun 2023 16:12
by rubber_jonnie
PhilC wrote: 09 Jun 2023 16:08
And it won’t go wrong at all now, well that was disappointing, I was hoping for more of a challenge.
It does look lovely and clean inside too, so now I’m off to try and find a tape lead for it.
IMG_2726.jpeg
I believe what you need is an ElkSD :)