Search found 245 matches

by anightin
Fri Aug 23, 2019 5:16 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Basically, what we are looking for, is any circuitry that operates from an independent oscillator. The SMPSU is the next (and most likely) suspect. Mark Today I pulled the PSU from my other Beeb and installed it into the patient. After 5 mins no OSD so I thought this was great. :) However after abo...
by anightin
Fri Aug 23, 2019 7:29 am
Forum: for sale / freebies
Topic: Freebies for collection at ABUG Sep 2019
Replies: 10
Views: 301

Re: Freebies for collection at ABUG Sep 2019

I'd like to take the Repton Disks off you please if I may. Happy to donate to the Computer Museum or a Charity of your choice in exchange. Best wishes Andy Now both bagged and packed :) Do feel free to donate to the Computer Museum if you're inspired by what they do but there's no obligation attach...
by anightin
Fri Aug 23, 2019 7:28 am
Forum: for sale / freebies
Topic: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse
Replies: 4
Views: 257

Re: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse

anightin wrote:
Fri Aug 23, 2019 7:06 am
Thanks @myelin, message received.

I got another offer via PM less than 24 hours before yours, so you are officially second in line.

Best wishes

Andy

Great news @myelin, the other buyer saw it was you who was interested and wanted you to have it instead. Congrats =D>
by anightin
Fri Aug 23, 2019 7:06 am
Forum: for sale / freebies
Topic: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse
Replies: 4
Views: 257

Re: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse

Thanks @myelin, message received.

I got another offer via PM less than 24 hours before yours, so you are officially second in line.

Best wishes

Andy
by anightin
Fri Aug 23, 2019 6:52 am
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

I guess that would be an easy one for me to try, having two Beebs, thanks for the suggestion @BigEd :D
by anightin
Thu Aug 22, 2019 10:39 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Is this machine using an original PSU? If yes, which type? By this I mean, an ASTEC SMPSU in the gold coloured case, or a conventional type in a black metal case. Gold PSU What else is connected to it? Are any expansions (internal or external) or peripherals connected? Do any of these have their ow...
by anightin
Thu Aug 22, 2019 9:29 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

So tonight I plugged the RGB output into the SCART input on a telly to see what was actually being presented to the SCART->HDMI box. As commented above, the TV did seem to be more forgiving in that there was no visible loss of sync or OSD being displayed. However what I saw was a band of interferenc...
by anightin
Thu Aug 22, 2019 1:13 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

tricky wrote:
Thu Aug 22, 2019 11:51 am
PS if you want to try the timing on the TV most still have a co.posited input even if the scart has gone.
Yup, I think we have a TV somewhere with a SCART input
by anightin
Thu Aug 22, 2019 1:12 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

1024MAK wrote:
Thu Aug 22, 2019 11:00 am
... high frequency circuits is one of them...

Mark
Fair enough, I guess I'll just have to swap 1 IC at a time in that case starting with no. 43 :)
by anightin
Thu Aug 22, 2019 10:36 am
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

roganjosh wrote:
Thu Aug 22, 2019 9:46 am
As Mark said, oscillators are a black art. I'd therefore substitute like with like i.e. get a 74S04 and not a 74ALS04.
Good hint, I might fit a socket first and experiment with both for a bit of fun.
by anightin
Thu Aug 22, 2019 9:00 am
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Thanks again folks, I will go down the route of: Trying the Beeb on a SCART TV to assess the quality of the direct output vs captured Source some components to swap out one at a time: IC41 SN74ALS02 IC43 SN74ALS04 IC48 SN74LS86AN Report back I also tried the OSSC I have that I usually run my Amiga a...
by anightin
Wed Aug 21, 2019 10:38 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Dear All, Got a new crystal in today and tried the machine -- short answer is no change of symptoms :( I was really hoping that would fix it :? IMG_4667.jpeg IMG_4668.jpeg IMG_4669.jpeg The red heat-shrink on the new crystal is there as I noticed the crystal touching the underside of the ROM/SWRAM b...
by anightin
Wed Aug 21, 2019 10:24 pm
Forum: for sale / freebies
Topic: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse
Replies: 4
Views: 257

Re: For Sale: Acorn A3020 + 4MB + CF HDD

**Any known issues: *Some of the keys on the LHS of the keyboard require a harder press for them to register -- I suspect the membrane needs a further inspection/some silver paint on the contact points to refresh. For example the D key didn't register at first but after multiple successive presses ...
by anightin
Wed Aug 21, 2019 10:12 pm
Forum: wanted
Topic: A3000 thru RiscPC
Replies: 6
Views: 155

Re: A3000 thru RiscPC

Beeb 1MHz Bus adapter build went quicker than expected tonight so with my extra time I set to cleaning up the A3020 keyboard -- result is that it now works perfectly. :D IMG_4674.jpeg IMG_4675.jpeg IMG_4676.jpeg I also dug out a mouse to go with it and updated the for sale thread. Best wishes Andy
by anightin
Wed Aug 21, 2019 11:09 am
Forum: wanted
Topic: A3000 thru RiscPC
Replies: 6
Views: 155

Re: A3000 thru RiscPC

With a mouse and working keyboard I am interested. Okay, if I have time this coming Bank Holilday Monday I'll look at the keyboard and update the post. I tried fixing myself but I'm struggling to solder with my eyes! I know what you mean! I was tracing the tracks under a magnifier for the A3020 -- ...
by anightin
Wed Aug 21, 2019 9:44 am
Forum: wanted
Topic: A3000 thru RiscPC
Replies: 6
Views: 155

Re: A3000 thru RiscPC

If you are interested I can throw in a mouse out of good will. :)

The keyboard is working, but I wanted to be completely transparent about what I found. If I get time I'll take it apart again and re-clean and test and update the post.
by anightin
Wed Aug 21, 2019 8:37 am
Forum: for sale / freebies
Topic: Freebies for collection at ABUG Sep 2019
Replies: 10
Views: 301

Re: Freebies for collection at ABUG Sep 2019

I'd like to take the Repton Disks off you please if I may.

Happy to donate to the Computer Museum or a Charity of your choice in exchange.

Best wishes

Andy
by anightin
Tue Aug 20, 2019 5:53 pm
Forum: wanted
Topic: A3000 thru RiscPC
Replies: 6
Views: 155

Re: A3000 thru RiscPC

By bizarre coincidence I just posted up my A3020 for sale.

viewtopic.php?f=8&t=17735

Not too far from Nottingham to Cambridge if you want to pop down! :D

Kind Regards

Andy
by anightin
Tue Aug 20, 2019 1:52 pm
Forum: for sale / freebies
Topic: For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse
Replies: 4
Views: 257

For Sale: Acorn A3020 + 4MB + CF HDD (Updated) + Mouse

Dear All, Needing to make space for a new machine :D Selling a clean, working** A3020, 4MB RAM, 512MB CF HDD. Internal expansion connector is still free for further upgrades. Just machine for sale, no box, manuals or mouse -- as it came to me. I have since been using it with a smally-mouse adapter a...
by anightin
Sun Aug 18, 2019 11:50 am
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Many thanks, will get a couple in and report back in a few days :)
by anightin
Sun Aug 18, 2019 10:32 am
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

Dear All, Thanks for all the suggestions so far. Had a quick play this morning and: S25 South to enable only 16K has no effect on the symptoms Swapping the Video ULA with the one in my issue 7 Beeb also had no effect on the symptoms I guess this should rule out ULA and lower 16K memory issues at lea...
by anightin
Sat Aug 17, 2019 9:31 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Re: Mode 7 intermittent lines

anightin wrote:
Sat Aug 17, 2019 8:23 pm
I must admit I'm claiming this as a MODE 7 issue but can't be sure I've not seen it in other modes -- I don't think I have.
Just to report, I have been running now in MODE 2 and have also seen the issue there now too.
by anightin
Sat Aug 17, 2019 8:23 pm
Forum: hardware
Topic: Mode 7 intermittent lines
Replies: 28
Views: 441

Mode 7 intermittent lines

Dear All, I am fortunate to have 2 BBC Model B's, however one is currently suffering a screen noise problem. It manifests as very short bursts of random lines every 60 seconds or so before settling again to an otherwise noise free solid display. IMG_4640.jpeg IMG_4641.jpeg (I captured the above usin...
by anightin
Sat Aug 17, 2019 3:51 pm
Forum: off-topic
Topic: Cheap Xilinx Platform Cable
Replies: 6
Views: 132

Re: Cheap Xilinx Platform Cable

Thanks peeps, I'll be sure to bring the platform cable in that case.

Will be interesting to see how it performs in different scenarios.
by anightin
Sat Aug 17, 2019 1:37 pm
Forum: off-topic
Topic: Cheap Xilinx Platform Cable
Replies: 6
Views: 132

Re: Cheap Xilinx Platform Cable

Hi Dave, Thanks for the swift response. Also, could you post a complete log that includes some of the unreliability. There may be come clues burried in that. I loaded iMPACT again but it doesn't seem to have kept the logs from yesterday. I'd rather not try and re-program the CPLD in the ATOM just in...
by anightin
Sat Aug 17, 2019 12:55 pm
Forum: off-topic
Topic: Cheap Xilinx Platform Cable
Replies: 6
Views: 132

Cheap Xilinx Platform Cable

Hi All, I've been using a 'cheap' eBay Xilinx platform cable (£18 vs £99?) for a recent CPLD project and perhaps not surprisingly have had some teething issues :| -- I am relatively new to FPGA/CPLD programming so didn't want to jump in at the deep end on price :) IMG_4630.jpeg I am using Win10 and ...
by anightin
Thu Aug 15, 2019 4:20 pm
Forum: general
Topic: Today I received.....
Replies: 5355
Views: 410635

Re: Today I received.....

If they had had support for Electron's I would have backed it..... but I did follow the project just because in ye olde days I wanted the original checkmate. Maybe it could be persuaded to house an (Ultimately) expanded Electron? As per ... https://stardot.org.uk/forums/viewtopic.php?t=9223 Persona...
by anightin
Thu Aug 15, 2019 3:53 pm
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 114
Views: 4715

Re: Beeb 1MHz Bus FPGA Adaptor

Some tips: - take your time deciding on connector spacing, and which way the cable flows - make sure the arrow on each connector (indicating pin 1) is at the red side of the cable - the connectors can be fitted to either side of the cable, this can help with neatness - if a device has soldered in t...
by anightin
Thu Aug 15, 2019 11:35 am
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 114
Views: 4715

Re: Beeb 1MHz Bus FPGA Adaptor

Thanks Dave, if just a case of crimping on an extra socket to an IDC cable then great :)
hoglet wrote:
Thu Aug 15, 2019 11:20 am
Let me know if you need me to post a photo.
Yes please when you have time, would be good to have a working reference just to be sure :)


Best

Andy
by anightin
Thu Aug 15, 2019 11:27 am
Forum: general
Topic: Today I received.....
Replies: 5355
Views: 410635

Re: Today I received.....

... a big heavy box with a case inside... IMG_4527.jpeg IMG_4528.jpeg I'm saving this for my Christmas and New Year project as I want to finish my 1MHz Beeb FPGA, ATOM SID and System build first before I play with this. I couldn't help having a quick peek though. :wink: Primarily I plan to fit an Am...