Search found 5023 matches

by danielj
Wed Aug 03, 2011 1:45 pm
Forum: hardware
Topic: BBC Model A S/N ICL 005416: Smokin!
Replies: 20
Views: 1636

Re: BBC Model A S/N ICL 005416: Smokin!

Stoppers wrote:
It's a CRT with a SCART (Panasonic 100Hz), but the BBC doesn't have an RGB socket.

Oooh, it's an old A? How B has it been made?

d.
by danielj
Wed Aug 03, 2011 1:28 pm
Forum: hardware
Topic: BBC Model A S/N ICL 005416: Smokin!
Replies: 20
Views: 1636

Re: BBC Model A S/N ICL 005416: Smokin!

The 0.01uF X2 capacitor has now been replaced, with no obvious effect, but at least I can stop worrying about the smoke. I've plugged in my FDD and... REVS!!! :) I can't see the screen properly, and I can't remember the controls, but :D Does anyone have any suggestions about the display? Do you hav...
by danielj
Tue Aug 02, 2011 3:59 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

It also came with a free religious conversion kit which was somewhat unexpected. :shock: You are joking aren't you? Nope, my CXA1645P was blessed on its way through Syracuse (I assume) and came accompanied by a small amount of reading material. :? But thanks, it was almost entirely not my own work ...
by danielj
Tue Aug 02, 2011 11:08 am
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Sony CXA1645P are also sold by LittleDiode but are £12+P&P+VAT making a Total of: £17.54 :shock: http://www.littlediode.com/components/CXA1645P.html !!!! I bought mine from http://syracusesemiconductors.com/ via ebay. Came to £12 including shipping from the US. I thought that was fairly steep t...
by danielj
Tue Aug 02, 2011 7:38 am
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Um 7am, no tea, short words only. *) No *) No, I didn't know the beeb was earthed! Pray tell me more! *) Yes, but I don't have an Atom PSU. Urgh ... cooooffffeeeeeee.... You don't need an atom PSU, just a 5V regulated one and seemingly at least 2amp. (That's what I use with my atom) - it might work...
by danielj
Mon Aug 01, 2011 12:19 pm
Forum: introduce yourself
Topic: The joy of beeb
Replies: 10
Views: 1202

Re: The joy of beeb

Hello!

d.
by danielj
Sun Jul 31, 2011 9:10 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Thanks guys, this has been really helpful. So, I've got the scope syncing to a single frame - this is the luma from a screen with some writing on. Ground is 1cm below the central line: http://youtu.be/IU4dzohwd1k You can see the noise at ground moving along. I checked the red input from the scart (s...
by danielj
Sun Jul 31, 2011 12:12 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Okay, 9V battery changes nothing. I've started attacking this with the scope, the linked video is of the sync output from the LM1881N. I'm not entirely sure what I'm looking at, but I assume the big signal which the scope's triggering off is the sync pulse, and that "stuff" moving along th...
by danielj
Fri Jul 29, 2011 8:27 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

I see, yes, that makes sense. Thanks! The PSU is one of those 500ma "pick the voltage, I'm regulated honest" ones and everything's plugged into the same 4 gang. I'm going to try and have a go at attacking this on Sunday, starting with powering it from a 9V battery...

d.
by danielj
Wed Jul 27, 2011 8:48 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Thanks there - I just realised I was being a moron before and treating the diode like a resistor for the voltage measurements. There wasn't anything out of the reg though against ground, that's why I changed it. I note from the data sheet that it doesn't seem to like 270C for more than 4 seconds, an...
by danielj
Wed Jul 27, 2011 8:09 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Yes, it was the T092. Diode was def. the right way around. I was getting 0 out of the regulator so I've swapped it for a 7805 which is behaving rather better :) - I'm just about to pop the resistor/capacitor on the SC pin. Seems the ghosting is only in the "fuzzy bands" that move slowly up...
by danielj
Wed Jul 27, 2011 6:03 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Hmm. It's a 2950, 5V. I'm only measuring 0.44V across the diode. Could I have toasted the reg soldering it?

Essentially it's:

Code: Select all

 
                Reg
+6v----|>+---- |Input
gnd------------|GND
vcc------------|output

Cheers,
d.
by danielj
Wed Jul 27, 2011 8:39 am
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

I notice the author mentions a missing capacitor in the errata which pertains to removing HF noise from the sync, I wonder if that could be related to your on-screen noise? Thanks :) Yes, I spotted that - I'll add that in and see what happens. I also realised I was bypassing my voltage regulator an...
by danielj
Tue Jul 26, 2011 7:45 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Okay, here we go... So I purchased one of the £15 scan rate converters I mentioned above. This works really well with composite but also has an s-video input. As I understand it, the s-video you can extract from a beeb is not "quite" right and you certainly can't get it out of an electron....
by danielj
Wed Jul 20, 2011 1:36 pm
Forum: off-topic
Topic: LOLPRICE
Replies: 2652
Views: 171221

Re: LOLPRICE

He KNOWS he's taking the Micky: "This package is worth over £1.357 GBP (aprox. $2.182 USD) but will be for grabs for the happy bidder starting from £777.00 (aprox. $1.250 USD)." Notice the use of decimal points and not commas? and... NO BUYER'S REMORSE or RETURNS? How about drunk impulse ...
by danielj
Thu Jul 14, 2011 6:20 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Oh, that is the Gnobes one, which is pants-o-matic - well to be fair to it for the price it is, it does work for some of the arcade stuff, and for composite, but I've got one of those, and after trying mine, and several others for people, I can't get it to display anything other than green gunge fr...
by danielj
Wed Jul 13, 2011 6:15 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

So I'm tinkering with s-video in a slightly different fashion, I'm going to convert the RGB to s-video using a dedicated IC (mentioned in other thread) instead of trying to cobble together the signal from bits/bobs/composite. I'll let you know how that goes, but in the meantime I thought I'd just sa...
by danielj
Mon Jul 04, 2011 8:52 pm
Forum: hardware
Topic: tricky to find IC
Replies: 2
Views: 450

Re: tricky to find IC

Thanks Mark, they're coming in a little bit more than the ebay seller, so unless this works and I start knocking more together I'll just run with them for now.

This is an experiment in lieu of having enough readies to acquire an uber-scan-converter... Shall keep everyone posted :)

d.
by danielj
Sun Jul 03, 2011 8:42 pm
Forum: hardware
Topic: tricky to find IC
Replies: 2
Views: 450

tricky to find IC

So, this is beeb related - I'm bodging some RGB to s-video malarchy. Any ideas where I can snaffle a sony CXA1645P for less than the £13 I'd have to cough up on fleabay? I believe RS used to do them, but no more it'd seem...

Cheers,
d.
by danielj
Fri Jul 01, 2011 6:27 pm
Forum: acorn atom
Topic: Atomstore by Program Power
Replies: 20
Views: 1934

Re: Atomstore by Program Power

Atom database? I'll try and load it...
by danielj
Sun Jun 19, 2011 6:26 pm
Forum: hardware
Topic: Tape input stuffed
Replies: 10
Views: 828

Re: Tape input stuffed

If you have a look at Mark's excellent reprint of the Beeb Service Manual, the fault finding section states that the most common reason for the "cassette system becoming inoperative is a damaged LM324". IC35.

d.
by danielj
Sat Jun 11, 2011 4:58 pm
Forum: hardware
Topic: Tinkering with S-Video
Replies: 90
Views: 5089

Re: Tinkering with S-Video

Also, what about this - I know it's not SVideo Paul, but could it possibly convert an RGB BBC signal to VGA ? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250675162632&ssPageName=STRK:MEWNX:IT#ht_3605wt_1154 I was thinking about this one... It does CGA to VGA, and Mike Cook once upo...
by danielj
Fri Jun 03, 2011 8:11 pm
Forum: introduce yourself
Topic: Hi I'm Matt
Replies: 20
Views: 1821

Re: Hi I'm Matt

Hello thar.

One of my favourite games back in the day - did you do the Electron version too?

d.
by danielj
Thu Jun 02, 2011 9:12 am
Forum: hardware
Topic: EPROM programmers
Replies: 11
Views: 1109

Re: EPROM programmers

Yes, it is, a 3B I think. I am going to try dropping a new inductor in and seeing what it does, but I thought it might be fun to build a beeb-one anyway.

d.
by danielj
Mon May 30, 2011 9:24 pm
Forum: acorn atom
Topic: Extract files from Atom TAP files.
Replies: 3
Views: 670

Re: Extract files from Atom TAP files.

Phill, I've got a little one I've written in java, attached...

java -jar tapsplit.jar filename.tap

It'll barf out all the atm files with 8 character names, spaces removed (not to say there won't be some dots here and there...).

d.
by danielj
Mon May 30, 2011 5:23 pm
Forum: hardware
Topic: Joystick pin confirmation
Replies: 3
Views: 453

Re: Joystick pin confirmation

Check out Mike Cook's beeb body building articles from the Micro User:

http://www.doc.mmu.ac.uk/staff/a.wisema ... index.html

In 1983 he did a "build your own joystick" one, along with how to interface a 9 pin atari one to the analogue port.

d.
by danielj
Mon May 30, 2011 9:33 am
Forum: hardware
Topic: BBC B colour loss
Replies: 315
Views: 15713

Re: BBC B colour loss

Right - got it on an MMC card and it is running now. Just sat there. Not saying much for itself. 5 minutes already and not a peep out of it so far. What's the best way of cleaning the IC socket contacts? They seem to be slightly corroded but I can't get anything slim enough in there to clean the co...
by danielj
Mon May 30, 2011 6:26 am
Forum: hardware
Topic: BBC B colour loss
Replies: 315
Views: 15713

Re: BBC B colour loss

I think that this is the replacement part for the processor... http://uk.farnell.com/microchip/pic16c77-04-p/ic-8bit-cmos-mcu-16c77-dip40/dp/9760172 ...but I can't find the RAM? That's a PIC, a processor, but certainly not what you want for a beeb. You need a 6502. I'm sure some people here will ha...
by danielj
Sun May 29, 2011 11:31 am
Forum: hardware
Topic: EPROM programmers
Replies: 11
Views: 1109

Re: EPROM programmers

george.h wrote: ye olde sparking coil in a car :lol: :wink:

George


Now... Can I use one of those instead? ;)

d.
by danielj
Sun May 29, 2011 10:25 am
Forum: hardware
Topic: EPROM programmers
Replies: 11
Views: 1109

Re: EPROM programmers

Except of course that the resistors on the output side (which are the ones which "see" the 21v) are only used in setting the reference voltage for the comparator to control the output voltage. They play no part in "carrying" the output through the load. That is all done by the i...

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