Search found 118 matches

by Marvin
Wed Nov 04, 2020 12:57 am
Forum: 8-bit acorn hardware
Topic: Acorn Electron keyboard Fault
Replies: 11
Views: 308

Re: Acorn Electron keyboard Fault

Could these be fault switches or a fault on the ribbon cable. is there anyway to fix? It's unlikely to be the key switches as they all share data line A6 (pin 16), so it's either the diode that's failed (unlikely) or a bad connection. It's most likely to be the ribbon cable at fault. I've bodged re...
by Marvin
Tue Nov 03, 2020 8:28 pm
Forum: general
Topic: Raspberry Pi 400
Replies: 45
Views: 1353

Re: Raspberry Pi 400

I used to have a 2MHz system with 32k of RAM. Oh hang on, I still do... Same here, you've only got to look at what 0xC0DE has achieved with his latest game Elementum with only 32K of RAM in total. I'd wager that a single icon on tarcus69 bloated Pi4 install requires more memory than that. I find it...
by Marvin
Tue Nov 03, 2020 10:40 am
Forum: general
Topic: Raspberry Pi 400
Replies: 45
Views: 1353

Re: Raspberry Pi 400

Also I have several 4Bs including an 8 gig version, they're still often painfully slow as a desktop system. What the heck are you running on it ? It must be some seriously bloated software. We used to "manage" with computers with CPU's that ran in the hundred mhz and only had a few megabytes of ram...
by Marvin
Tue Nov 03, 2020 1:01 am
Forum: 32-bit acorn hardware
Topic: How do you add a second hard disk?
Replies: 6
Views: 284

Re: How do you add a second hard disk?

Incidentally how do you configure the number of CDROMs I can see nowhere to set it or is it a *CONFIGURE thing? Currently the CDROM does not show up at all on the icon bar so I assume the setting was lost when the battery was replaced. How do I reinstate it if indeed I can. The CD is loose inside s...
by Marvin
Mon Nov 02, 2020 9:10 pm
Forum: 8-bit acorn hardware
Topic: Electron Plus 3, some questions.
Replies: 26
Views: 1891

Re: Electron Plus 3, some questions.

We've tried a new 20V 3.25A DC PSU on it. It will power the electron o.k. Powering the plus 3 without the electron the disc drive powered up and spins, light comes on etc. Connecting the electron and trying again and the light on the disc drive flickers for a second and then stays out, drive doesn’...
by Marvin
Mon Nov 02, 2020 4:30 pm
Forum: 32-bit acorn hardware
Topic: How do you add a second hard disk?
Replies: 6
Views: 284

Re: How do you add a second hard disk?

If you do replace the CD Drive with a 2nd Hard Disc don't forget to configure the number of CDROM drives to 0 unless you like having unused/unnecessary drive icons on your Iconbar. The CDROM drive bay is a good place to mount additional hard drives, all you need is a couple of bolts up through the b...
by Marvin
Mon Nov 02, 2020 12:02 pm
Forum: 8-bit acorn hardware
Topic: Elk Audio Mod
Replies: 3
Views: 214

Re: Elk Audio Mod

That break mod could be handy, not that I ever press break rather than delete :^o For audio, I think if I were to use headphones rather than connecting to the TV, I'd probably want to add a volume control. Funny how a simple mod seems to lead to more and more :) If you want pics of the Break Key mo...
by Marvin
Mon Nov 02, 2020 12:46 am
Forum: 8-bit acorn hardware
Topic: Elk Audio Mod
Replies: 3
Views: 214

Re: Elk Audio Mod

For extra credit if anyone fancies attempting this. I expect you could get a 3.5mm socket that lets you break a connection when a plug is inserted. Switching between the internal speaker to be used or headphone/TV automatically. I might look into that another day. Yup did that 30+ years ago, I used...
by Marvin
Mon Nov 02, 2020 12:36 am
Forum: miscellaneous new bbc and electron games
Topic: Elementum for Electron and BBC Micro/Master
Replies: 35
Views: 1758

Re: Elementum for Electron and BBC Micro/Master

hicks wrote:
Mon Nov 02, 2020 12:05 am
have you also considered a running deaths counter.
Noooooo!

I really don't want to know how many times I've "died", It's got to be in the many hundreds by now... :lol:

And as for adding a harder mode, that's just sadistic :D
by Marvin
Sat Oct 31, 2020 6:23 pm
Forum: 8-bit acorn hardware
Topic: Cub monitor - can't correct pincushion
Replies: 5
Views: 269

Re: Cub monitor - can't correct pincushion

Are all the steering coils on the tube secure ? The reason I ask is many years ago I had a CRT display that suffered from terrible distortion, I can't remember if it was pin cushioning or barrel but what had happened is one of the coils that steers the beam had moved so no amount of electrical adjus...
by Marvin
Fri Oct 30, 2020 7:57 pm
Forum: 32-bit acorn hardware
Topic: RIP SIMM slot
Replies: 9
Views: 433

Re: RIP SIMM slot

Do all the pins buzz out okay on the other slot ? Because if they do I'd be trying to get the machine operational first and then fix the dodgy simm slot later once I'd proved it was a goer rather than try fixing that simm slot and perhaps still having a dead motherboard.
by Marvin
Fri Oct 30, 2020 7:52 pm
Forum: off-topic
Topic: LOLPRICE
Replies: 3016
Views: 357124

Re: LOLPRICE

Acorn SCSI card just went for £132 :shock:

https://www.ebay.co.uk/itm/324341976999

I know that they are one of the few SCSI podules that work with Risc iX but is that really what they are worth ? Am I being naive or tight ?
by Marvin
Thu Oct 29, 2020 11:44 pm
Forum: 32-bit acorn hardware
Topic: RIP SIMM slot
Replies: 9
Views: 433

Re: RIP SIMM slot

Just thinking laterally for a moment why not just remove the socket and not replace it, the Risc PC has 2 memory slots, surely you can fit a big enough stick of ram in the other socket for the machine to be useful ?

or is that one knackered as well ?
by Marvin
Thu Oct 29, 2020 8:51 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

It looks as if the interrupt is constantly triggering the LS122 so keeps it's output Low. If it misses an interrupt or they stop (not worked out the TC yet) the working LED may either flash or go out altogether (dependant on TC) and the Low LED with flash or stay on. Not sure how the High LED would...
by Marvin
Thu Oct 29, 2020 2:19 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

So we any idea what it does, does it short anything or send anything to elk to make it carry out the soak test? It only monitors the Electron, it in no way that I can see controls or triggers the machine so I can't see it doing any harm in plugging it in and seeing what happens. I'm curious what pl...
by Marvin
Thu Oct 29, 2020 11:01 am
Forum: 8-bit acorn hardware
Topic: Now someone's pinched my capacitors!
Replies: 21
Views: 578

Re: Now someone's pinched my capacitors!

For what it's worth, an experienced hardware repair person from the Apple II world advised me they just remove those filtering caps and don't replace them. You are correct - they filter nasty harmonics from the SMPS from getting back onto the mains lines and affecting other devices. I think this wa...
by Marvin
Thu Oct 29, 2020 10:47 am
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

Yes, rechecking, I agree the silk screen for Q2 and Q3 does have the “e” in the wrong place. Maybe the board was originally intended to have NPN transistors and then they realised they had the wrong logic! Thanks for the sanity check, hopefully I haven't made any mistakes on this schematic (it's ve...
by Marvin
Thu Oct 29, 2020 12:23 am
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

Aren’t all the silk screen LED polarity markings misleading? Yes they are all wrong. I can’t see a problem with Q2 though. With both Q2, Q3, R7, R10, LED1 and LED2, it is slightly unusual to have a 150 ohm resistor (to limit the LED current in the collector) in the emitter circuit for what is other...
by Marvin
Wed Oct 28, 2020 10:18 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

I was just checking my schematic is correct before posting it when I noticed the the silk screen for LED 3 puts the "+" on the wrong leg (I think) but I've stared at this so much I'm doubting myself so now I'm triple checking all my workings out. :roll: <edit> I now think the silk screen is wrong fo...
by Marvin
Wed Oct 28, 2020 6:52 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

daveejhitchins wrote:
Wed Oct 28, 2020 5:07 pm
R9 goes to pin 5 of IC2.

IC1 - 74LS00
IC2 - 74LS122
Q1 - BC239
Q2 - 2N3906
Q3 - 2N3906
Q4 - BC239
IMG_0963.jpgIMG_0965.jpg


Dave H.
Cheers Dave, that clears it up for me perfectly, I'll update my schematic and post it later.
by Marvin
Wed Oct 28, 2020 1:00 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

Will see what I can do when get another moment to open it :) Still awaiting those clearer pictures :D Can you please buzz out where the track from R9 goes to under the 74122 chip, I suspect pin 3. Also what's the numbers on the transistors ? I've nearly got my schematic finished but I want to be ce...
by Marvin
Wed Oct 28, 2020 1:17 am
Forum: 8-bit acorn software: other
Topic: ADFSBox
Replies: 4
Views: 317

Re: ADFSBox

Ok, so I got a reply from the author, who without saying a word just sent me a link to his website. I was a little disappointred :D Yes he can be rather terse at times, I've always got on okay with him but others have found him rather hard to deal with. ADFSbox 1.1.BIN.zip I have no idea if it is o...
by Marvin
Mon Oct 26, 2020 8:54 pm
Forum: miscellaneous new bbc and electron games
Topic: Elementum for Electron and BBC Micro/Master
Replies: 35
Views: 1758

Re: Elementum for Electron and BBC Micro/Master

maybe I shouldn't hold the turbo button down all the time! When I first started playing this game I never used the turbo button unless I needed it for a longer jump. As I got better at playing it I started using the turbo button to complete the level faster and get a higher bonus score. Not trying ...
by Marvin
Mon Oct 26, 2020 7:34 pm
Forum: miscellaneous new bbc and electron games
Topic: Elementum for Electron and BBC Micro/Master
Replies: 35
Views: 1758

Re: Elementum for Electron and BBC Micro/Master

Great game, but I can't get used to falling off a lpatform and then jumping in mid-air, I guess I am just too old ;) Thanks tricky! Yes, it takes some time to get used to "coyote time" but it may save you a few times in some levels. Would I be correct in thinking that some later levels actually req...
by Marvin
Mon Oct 26, 2020 10:37 am
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

You couldn't post some clearer pictures could you (square on to the camera and well lit), especially of the underside some of the tracks are very hard to make out. If you can read any of the capacitor values that would be helpful especially of C4(?) i think (it's the one to the right of R1) But as n...
by Marvin
Mon Oct 26, 2020 9:55 am
Forum: miscellaneous new bbc and electron games
Topic: Elementum for Electron and BBC Micro/Master
Replies: 35
Views: 1758

Re: Elementum for Electron and BBC Micro/Master

I've no idea if you've messed with the music as my machine is back muted again but I have to say it's a very polished game =D> =D> =D> This is weird! Have you tried pressing Q (quiet) and S (sound)? There should be a tune when you're at the title screen. And sound effects when you're playing. I hav...
by Marvin
Mon Oct 26, 2020 12:52 am
Forum: miscellaneous new bbc and electron games
Topic: Elementum for Electron and BBC Micro/Master
Replies: 35
Views: 1758

Re: Elementum for Electron and BBC Micro/Master

Old habits die hard... First thing I did was examine the disc image, the level names were easy to spot but I'm still looking for the password table :D I better get back to playing the game, I'm still finding level 8 damned hard to complete. I see you've been tweaking the scoring again, the time bonu...
by Marvin
Sat Oct 24, 2020 2:39 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

Interesting... The following pins are soldered on the edge connector 1, 2 AC in 7, 8 0v 17, 18 IRQ, R/W 27, 28 RDY n/c 39, 40 A1 A2 49, 50 +5v but most are being used only to hold the connector, only pins 7+8, 17, 49+50 look to be wired up, so that's only 0 volts, +5 volts and IRQ. I'll trace the ci...
by Marvin
Sat Oct 24, 2020 10:39 am
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

mr-macrisc wrote:
Thu Oct 22, 2020 10:40 pm
I have bought one, there is another available...

Will open up and take photos etc when it arrives and plug it in and see if any roms show up.
Good stuff, I'm looking forward to seeing the pictures.
by Marvin
Thu Oct 22, 2020 8:56 pm
Forum: 8-bit acorn hardware
Topic: Electron Watchdog? (Soak tester)
Replies: 39
Views: 1078

Re: Electron Watchdog? (Soak tester)

So who's going to buy it and then open it up to work out what it does ?

I don't do faecesbook so it ain't gonna be me...

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