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Messages - dangerman

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Hardware / Re: Broken 12V
« on: 2019.July.20. 09:55:43 »
Finally got it fixed and working.

It was nothing to do with the coil. There was some kind of a problem with the BC337-40. I replaced it with another one (also BC337-40 as that's all I have) and it now works. :smt041

Wanted / Re: EP Case etc.
« on: 2019.July.20. 09:49:56 »
project EnterPC!
20 years ago, I had just that same idea because I had a spare EP motherboard lying around.

I got most of the way through re-wiring a keyboard, but then I left home for university and the project was never finished. Happy memories though. :ds_icon_cheesygrin:

Hardware / Re: Broken 12V
« on: 2019.July.15. 13:07:45 »
Thanks - that's good to know. So hopefully the transistor is good.

I'll try adding some more windings to the coil. I'm aiming for 14.5V input to the 78L12 regulator.

Hardware / Re: Broken 12V
« on: 2019.July.14. 23:29:55 »
I finally found some time to look into fixing my EP. But I'm a bit out of my depth with analogue electronics! Things are definitely improving, but the input to the 12v regulator 78L12 is currently only at 10V

I got some replacement parts from an electronics store. I tried to find the closest replacements that I could, but the wire that I bought to repair the coil is 0.236mm, not 0.25mm. I left the inner winding on the coil (the red wire) as that didn't seem to be damaged. Maybe I should have rewound both the windings.

The other problem is that I asked for BC337 transistors and they have given me BC337-40 transistors. Looking at a datasheet the only difference that I have found is the minimum DC current gain.

DC Current Gain hFE (IC = 100 mA, VCE = 1.0 V)
BC337            Min 100 Max 630
BC337–40      Min 250 Max 630

Can anyone tell me what the implications are. Is it okay to use that transistor?

If the transistor is okay, I'm thinking I'll just add a few more windings to the coil to see if I can increase the voltage...

Interface / Re: USB to Enterprise serial
« on: 2019.July.02. 21:40:42 »
I was considering writing a simple zmodem client for the Enterprise. But then my EP stopped working and so I'll have to fix that first unfortunately :(

Also, since I had to open it up to try and fix it, I had the bright idea to "upgrade" it to 6MHz. But of course this will destroy all the timings for the serial driver. Seemed like a good idea at the time, though.

As an alternative, is there any serial support in ep128emu?

Wanted / Re: SD card interface
« on: 2019.May.19. 13:37:52 »
Yes - he does this in his spare time so it can take a long time. But it's worth the long wait, because the SD interface is great.

And the good news is that the new SD boards can also have a real time clock. And also FAT16 support is coming in the future too.

CPC-ről / Re: R-Type
« on: 2019.March.30. 10:09:37 »
The Spectrum version of R-Type was absolutely brilliant. But this CPC remake is even more amazing!!

Fantastic to have it on the Enterprise as well. :smt041

Hall of Fame / Re: Q&A with Bruce Tanner (IS-BASIC writer)
« on: 2019.March.29. 19:52:34 »
Not yet, they are a mess of files from various programs all mixed together, so not really usable currently. A long-term project for Zozo...

I see... I'm happy to help sort through stuff if Zozo wants any help.

Hall of Fame / Re: Q&A with Bruce Tanner (IS-BASIC writer)
« on: 2019.March.23. 14:46:24 »
Wow, that's a load of great information!

Are the source codes downloadable anywhere? I couldn't find them in the thread but maybe I missed something as there's so much there.

Hardware / Re: Broken 12V
« on: 2019.March.23. 12:15:36 »
Good idea about EPower, although I think I don't really want to replace everything. The 5V is working fine.

Do you need your spare coils, or would you be able to send me one? It would be great if I could fix it.

Hall of Fame / Re: Q&A with Bruce Tanner (IS-BASIC writer)
« on: 2019.March.23. 12:08:29 »
Very interesting. Where did these IS documents come from?

Hardware / Re: Broken 12V
« on: 2019.March.17. 22:20:38 »
Thanks for the tip, Pear. I'll get some 0.25mm enamel wire and give it a go myself.

Is there any way to confirm whether it is the coil that is causing the problem? Could it be another component that is causing the short?

Hardware / Broken 12V
« on: 2019.March.17. 18:41:19 »
Last weekend, I started having problems with my Enterprise 64 and I realised there were problems with the 12V circuit. Thanks to previous posts on Enterprise Forever, I discovered the most common fault is with TR2 and C9. So I replaced them both and it started working again. I thought this had fixed the problem.

However, yesterday I plugged in the Enterprise and disaster happened! Smoke came from the case and TR2 was completely melted, and the wire to coil L1 had broken as well. :cry:

Thankfully the rest of the computer seems to work if I wire in an external 12V source... so it's only the 12v circuit that's blown. That is a big relief!

Anyway, I replaced TR2 and C9 again and patched the wire to coil L1, but when I tried power it up - more smoke started coming from TR2, so I unplugged it quick. I think TR2 must be short circuited somehow. Looking at the schematics and using my very limited grasp on electronics, I guess the culprits are going to be C10, TR3 or the coil L1. Does anyone know how I might narrow this down? I have a multimeter but don't have access to an oscilloscope. Is it even possible to get a replacement coil???

All help gratefully received. :(

Programming / Re: FILE program
« on: 2019.February.17. 17:42:32 »
Thank you! :)

Programming / FILE program
« on: 2019.February.17. 12:43:30 »
I really like the FILE program that comes with the SD interface. I wondered if I could request an added feature?

At the moment if you select a drive that doesn't exist (like C:) then you get a Retry/Abort and then the program quits.
I was wondering if it would be possible to just display a blank screen, so that then you could get a chance to select another drive.

Is the source code available for this program? ;-)

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