Search found 172 matches

by gidandridge
Sun Feb 21, 2021 11:47 am
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Re: Faulty Electron - Boots to red/yellow pattern

More updates ... I'm starting to run out of ideas to help bring this old Elk back to life. :( I ended up replacing all of the 4164 RAM chips. This has certainly resulted in a change, but I can't work out if that's a good sign or not. With all the new 4164's in place when I boot up I now get this ......
by gidandridge
Sat Feb 20, 2021 7:44 pm
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Re: Faulty Electron - Boots to red/yellow pattern

So an update ... A replacement 6502 CPU arrived earlier this week, courtesy of Dave H. Thanks Dave! I'm pleased to report that after fitting this I could see a clock pulse on pin 37, so that seems to have fixed the dead CPU issue. :D Sadly it still won't boot. So since the OS ROM was already in a so...
by gidandridge
Tue Feb 16, 2021 6:21 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 97
Views: 6836

Re: Electron ULA Basic Board

Budgie wrote:
Tue Feb 16, 2021 6:15 pm
I included a link to a Drag Soldering example on youtube in the wiki (BOM) which is great but does make it look easy !
:lol: - I think I've seen a few similar videos on YouTube which, as you say, make it look ludicrously easy. I won't be posting pictures of my first attempts!
by gidandridge
Tue Feb 16, 2021 6:09 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 97
Views: 6836

Re: Electron ULA Basic Board

Your list is basically correct, except the RTL for this board is on my site as provided by Dave above. Hopefully the info in the Wiki should explain everything. Let me know when you get it to a stage for programming and I can provide the .pof file for programming the FPGA to at least ensure that is...
by gidandridge
Tue Feb 16, 2021 7:36 am
Forum: 32-bit acorn hardware
Topic: RiscPC700 with "hilarious" attempted RTC fix
Replies: 26
Views: 598

Re: RiscPC700 with "hilarious" attempted RTC fix

Nice clean up job. Impressive. =D>
by gidandridge
Mon Feb 15, 2021 9:06 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 97
Views: 6836

Re: Electron ULA Basic Board

I've looked in Hoglet's github for the Kicad file but can't see them, only Myelin's files. Am I being blind? Same for a bill of materials can only see the list for the "Ultimate Electron Upgrade" project. :-? (Admittedly I've not opened any files up in Kicad, was just trying to work it ou...
by gidandridge
Mon Feb 15, 2021 8:57 pm
Forum: off-topic
Topic: LOLPRICE
Replies: 3075
Views: 389397

Re: LOLPRICE

... but it has a "Make offer" button, so I'm sure they will accept a reasonable offer, right? :lol:
by gidandridge
Mon Feb 15, 2021 8:48 pm
Forum: wanted
Topic: Wanted - Electron ULA (Hilarious, I know!)
Replies: 0
Views: 95

Wanted - Electron ULA (Hilarious, I know!)

So this is possibly the most ridiculous wanted post ... I have an Elk with a dead ULA, I don't suppose someone has a good ULA? :lol: Sorry, I figured, don't ask, don't get right? I appreciate that Elk ULA's are literally gold dust. :roll: Failing this I'm going to have a go at building an FPGA based...
by gidandridge
Sun Feb 14, 2021 9:07 pm
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Re: Faulty Electron - Boots to red/yellow pattern

Amazing thanks Dave, Have replied to the PM

I think this Elk must have had a hard life in it's past :-k
by gidandridge
Sun Feb 14, 2021 5:11 pm
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Re: Faulty Electron - Boots to red/yellow pattern

Try checking the continuity between the ULA pin (ULA removed) to the 6502. If It's OK then leave the ULA out and try a pull-up resistor from the 6502 pin 37 to +5V - this will check that the 6502 pin isn't the problem. Thanks Dave. So the continuity between pin 37 on the CPU and pin 60 on the ULA i...
by gidandridge
Sun Feb 14, 2021 4:44 pm
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Re: Faulty Electron - Boots to red/yellow pattern

Check the contacts of the ULA socket e.g. remove the ULA and check the height of each contact from all angles! Dave H. Thanks Dave, all looking good I think. All the pins in the socket seem intact and at the right heights. I've given the pins and the ULA a clean with IPA. So I think it should be ok...
by gidandridge
Sun Feb 14, 2021 3:18 pm
Forum: new projects in development: games
Topic: Electrobots - new game for Elk/Beeb/Master
Replies: 65
Views: 2350

Re: Unnamed Elk/Beeb robot game

This is looking great. Love the graphics. :D
by gidandridge
Sun Feb 14, 2021 3:01 pm
Forum: 8-bit acorn hardware
Topic: Faulty Electron - Boots to red/yellow pattern
Replies: 11
Views: 349

Faulty Electron - Boots to red/yellow pattern

So I am trying to fix one of my Electron's that is faulty. It is an issue 4 board. Right now I have it booting up to the following display: IMG_20210214_144343.jpg Originally I did find a problem with the clock. When I used my logic probe to test IC8 (74S04) pin 8 was low. Looking at the circuit dia...
by gidandridge
Sun Feb 14, 2021 12:19 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 97
Views: 6836

Re: Electron ULA Basic Board

I have been watching this thread with great interest as I have an Elk with a dead ULA that I'd like to restore to working condition. I have to admit that I've not played with FPGA's before so it will be a bit of a learning curve but I've been doing lot's of reading and also digesting this post. So I...
by gidandridge
Sun Feb 14, 2021 12:01 pm
Forum: 8-bit acorn hardware
Topic: BBC Model B PSU voltage issue with IFEL ROM/RAM board
Replies: 5
Views: 298

Re: BBC Model B PSU voltage issue with IFEL ROM/RAM board

Is this on the part of the spade where the wires are connected, or on the part that is attached to the PCB? Only this looks like either loose fitting spade terminals, or dry joint space on the PCB. It does not look like a PSU problem. Also, which issue board is this? Thanks Mark, sorry for the slow...
by gidandridge
Sun Jan 17, 2021 4:47 pm
Forum: 8-bit acorn hardware
Topic: BBC Model B PSU voltage issue with IFEL ROM/RAM board
Replies: 5
Views: 298

Re: BBC Model B PSU voltage issue with IFEL ROM/RAM board

Have you had a chat with Steve Picton, the builder of said board? (IFEL) - he's normally very helpful about these things? I have thanks. You're right he has been very helpful. His did point me into checking the 5v voltage and explained that the critical voltage for his baord is 4.62v as mentioned a...
by gidandridge
Sun Jan 17, 2021 3:44 pm
Forum: 8-bit acorn hardware
Topic: BBC Model B PSU voltage issue with IFEL ROM/RAM board
Replies: 5
Views: 298

BBC Model B PSU voltage issue with IFEL ROM/RAM board

Hi All, I have a question about the 5v voltage level in my Model B beeb. Months back I bought a ROM/RAM IFEL addon board. This provides the full bank of 15 ROM slots with half of them stored in battery backed RAM. The board uses a DS1210 IC that switches over to battery backed mode if the 5v line dr...
by gidandridge
Sun Jan 17, 2021 2:21 pm
Forum: new projects in development: games
Topic: Electrobots - new game for Elk/Beeb/Master
Replies: 65
Views: 2350

Re: Unnamed Elk/Beeb robot game

Wow - this looks amazing so far. =D> :D
by gidandridge
Sun Jan 17, 2021 12:18 pm
Forum: 8-bit acorn hardware
Topic: Cub monitor horizontal hold - fixed.
Replies: 1
Views: 122

Cub monitor horizontal hold - fixed.

Hi All, I recently had a my Cub Monitor develop a fault with it's horizontal hold. I've resolved it now but thought I would post my experience here in case it may help anyone else. So it started a few weeks back. I noticed that there was a ripple on the horizontal hold. This looked like various line...
by gidandridge
Sun Jul 26, 2020 5:50 pm
Forum: past all-day virtual ABugs
Topic: All-day 'Virtual' Acorn session #6, Saturday 1st August 2020, 9am - 11pm [NOW FULL!]
Replies: 105
Views: 7211

Re: All-day 'Virtual' Acorn session #6, Saturday 1st August 2020, 9am - 11pm

Can I join in please. :D

I'm not sure how much of the day I cam make, Should be good from 2pm until 10pm with some dinner in there somewhere. May even be able to start at 9am but can't guarantee.

Cheers.
by gidandridge
Mon Jun 29, 2020 9:42 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

Nice 👍 8) You know you are an old git when the off spring / niece / nephew / whatever complain about a noise from a CRT TV / monitor that you can’t hear anymore.... So forget buying that nice expensive hi-fi system, it’s 50 to 20 MHz frequency range will be wasted on an old git who can’t hear audio...
by gidandridge
Mon Jun 29, 2020 7:30 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

Keep in mind that if the monitor is kept inside in a room that is warm and dry, then the rate of rusting will be very slow. Mark Well my "retro cave" is my loft. Fully converted and fully insulated. So hopefully with the clean up I did and the warm dry environment I think it should be oka...
by gidandridge
Sun Jun 28, 2020 10:15 am
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

The advice to me back then, and which I pass on to you, is don’t touch anything that will disturb the physical magnetic set-up / calibration. Otherwise you will have to try to realign everything from scratch... So the urge to remove the spring clips is starting to fade ..... If you move it, you'll ...
by gidandridge
Sun Jun 28, 2020 9:53 am
Forum: acorn atom and acorn system series
Topic: Atom delivery by Hermes
Replies: 21
Views: 1616

Re: Atom delivery by Hermes

That's a truly shocking amount of damage. :shock: :(
by gidandridge
Sat Jun 27, 2020 7:59 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

New BC337 transistors should be easy to find (they are still in production). Mark Thanks mark, ordered, arrived, fitted and replaced. :D I've been busy the last week so only had time to work on it today. All going well and I had planned to reassemble everything tomorrow. However this evening I was ...
by gidandridge
Sat Jun 20, 2020 8:13 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

Update, so I have been reading ... Servicing the Microvitec Cub Series 3 - by Arthur Rumbelow. From Television Magazine, August 1992, page 718. (https://docplayer.net/89011606-Servicing-video-satellite-developments-free-catalogue-inside-servicing-the-finlux-3000-chassis-ad-converters-for-dmms-dx-tv....
by gidandridge
Sat Jun 20, 2020 7:15 pm
Forum: 8-bit acorn hardware
Topic: (Repair/Refurb) Microvitec Cub 653 (1451DS)
Replies: 13
Views: 1063

Re: (Repair/Refurb) Microvitec Cub 653 (1451DS)

I've just finished fixing this one. Full recap and a new PTC later, and the shimmering's gone - I'd call that a win. =D> Well done! Glad it's fixed it all. Another Cub monitor back to good health. Do you think it was the PTC in the end that was causing your shimmering? Did you ever try and run it w...
by gidandridge
Sat Jun 20, 2020 7:05 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

Someone’s been changing capacitors before you I think... I'm sure you're right Mark. Quite why anyone would choose to replace a capacitor with a a noticeably lower capacitance though? Pass on that one. :-k And are you trying to confuse us... C26 < - > C28? Mark Ah, yes, You got me. The errant 10uF ...
by gidandridge
Sat Jun 20, 2020 3:58 pm
Forum: 8-bit acorn hardware
Topic: Microvitec Cub - Needs some help (Refurbishment)
Replies: 20
Views: 1316

Re: Microvitec Cub - Needs some help (Refurbishment)

B.T.W. what value is fitted in position C27? C27 being the first stage smoothing/decoupling for the 124V power rail, and is C28 the same make as C27? Thanks Mark. So this is what was fitted to the board for C26, C27 and C28. IMG_20200620_155201.jpg The two 47uF Rubycon's were in C27 and C28. The 10...
by gidandridge
Fri Jun 19, 2020 7:22 pm
Forum: 8-bit acorn hardware
Topic: (Repair/Refurb) Microvitec Cub 653 (1451DS)
Replies: 13
Views: 1063

Re: (Repair/Refurb) Microvitec Cub 653 (1451DS)

D'oh, I think I may have gotten axial and radial mixed up! I'll probably sub in a poly film capacitor for it and the 680nF. So for the 1uF 63v C18 I've just ended up ordering one of these ... https://uk.farnell.com/multicomp/mcmhr63v105m4x7/cap-1-f-63v-20/dp/9452737 ... so yes that is a radial, and...

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