Search found 203 matches

by johnkenyon
Tue Jun 11, 2019 2:37 pm
Forum: hardware
Topic: 1770 wire links
Replies: 12
Views: 177

Re: 1770 wire links

If I don't have any spare resistor/<insert any other radial electronic component here> legs lying around the bench, I would reach for the reel of insulated single strand insulated copper wire, strip one end, cut link size+1cm, then strip the other end. Bend neatly with pliers and insert. For links l...
by johnkenyon
Tue Jun 11, 2019 10:22 am
Forum: hardware
Topic: 1770 wire links
Replies: 12
Views: 177

Re: 1770 wire links

Elminster wrote:
Tue Jun 11, 2019 9:48 am
I guess to get them as good at the ones you get in the kit you would want to heat shrink some heat shrink in the middle of your resistor leg.
Or increase the leg length (if inserted in an IC socket), or solder with an air gap between wire and PCB if being soldered in...
by johnkenyon
Tue Jun 11, 2019 9:18 am
Forum: hardware
Topic: 1770 wire links
Replies: 12
Views: 177

Re: 1770 wire links

Take a couple of resistors from that pack of 1000 you got cheap on eBay, clip the leads off, bend to the right spacing with your pliers, trim to length, install....
That's the cheap way...
by johnkenyon
Thu May 23, 2019 12:24 pm
Forum: software
Topic: How to clone a 'master' disc on Archimedes
Replies: 17
Views: 370

Re: How to clone a 'master' disc on Archimedes

Now here's a thing... Tried !Rat (!Pirat) on my A5000 last night and it crashed out and wouldn't copy the Touch Window disk. Copied the program to my A3000 and it worked perfectly making a virgin 'Master' disk which then would register to my A3000. :D Is this because the A3000 has an 800K drive and...
by johnkenyon
Tue Mar 26, 2019 11:05 am
Forum: other vintage computer hardware, software and games
Topic: Megastor 8" drive unit
Replies: 66
Views: 1659

Re: Megastor 8" drive unit

I would suggest a small AVR or PIC device.
Then you could code whatever parameters you like - delayed spinup, delayed spindown, with no rummaging around the parts bin looking for resistors or capacitors when you want to change.
by johnkenyon
Fri Mar 22, 2019 3:11 pm
Forum: hardware
Topic: Best SD card disk drive for the beeb
Replies: 9
Views: 410

Re: Best SD card disk drive for the beeb

B+ Doesn't have the HAZEL RAM that the Master uses for filing systems... d. See: http://beebwiki.mdfs.net/ANDY There's a job there for someone who wants to rewrite/extend the B+ MOS to support service calls &21, &22, &24, and supports HAZEL for calls &0F, and possibly &12. Then they'd have to tweak...
by johnkenyon
Thu Mar 21, 2019 9:29 am
Forum: other vintage computer hardware, software and games
Topic: UM1662 RF Modulator
Replies: 2
Views: 144

Re: UM1662 RF Modulator

I've also found out that the A3010 used a UM1662. Unfortunately the A3010 doesn't have a composite video output, so I can't see how the UM1662 video in differs from bog standard CVBS out. I'm struggling to find a useful Atari circuit diagram. I think I will just suck it and see. My expected problems...
by johnkenyon
Wed Mar 20, 2019 12:23 pm
Forum: other vintage computer hardware, software and games
Topic: UM1662 RF Modulator
Replies: 2
Views: 144

UM1662 RF Modulator

Whilst rummaging around a box of spares I've found a UM1662 RF modulator - It modulates video+mono sound onto channel 36 with the sound on the former UK standard 6MHz subcarrier. I can find a couple of photos of the first page of the datasheet, and absolutely nothing else. I then thought of searchin...
by johnkenyon
Mon Mar 11, 2019 2:15 pm
Forum: off-topic
Topic: RCM on the TV
Replies: 2
Views: 234

Re: RCM on the TV

I just saw an announcement on the local BBC news that the RCM is going to be on "Inside Out" East Midlands tonight as they cover the "craze" of collecting old home computers. I'm guessing that the show will appear on the following link sometime after 8:30pm tonight (11th March) for everyone that do...
by johnkenyon
Fri Mar 08, 2019 8:17 am
Forum: hardware
Topic: Rom daughterboard
Replies: 19
Views: 602

Re: Rom daughterboard

1. IC76 You need to fit a 74LS163 (BBC B Circuit diagram and others here: http://mdfs.net/Info/Comp/BBC/Circuits/ look for bbc.gif ) Note that the header from the daughterboard may have spread out the contacts making an IC a loose fit. The fix is either to replace the socket, or if you want to avoid...
by johnkenyon
Tue Mar 05, 2019 5:02 pm
Forum: other vintage computer hardware, software and games
Topic: Megastor 8" drive unit
Replies: 66
Views: 1659

Re: Megastor 8" drive unit

What's the 40 pin device?
(Edit: Cancel that question - found this https://www.mirrorservice.org/sites/www ... manual.pdf
and it says "Large Scale Integrated Circuit BASF 81041-001")

And have you located a replacement?
by johnkenyon
Sat Mar 02, 2019 12:23 am
Forum: hardware
Topic: Am I a Monster?
Replies: 22
Views: 728

Re: Am I a Monster?

I replaced the BNC connector on one of my Beebs with a chassis phono socket. BNC connectors are reserved for test gear and 10base2 as far as I'm concerned. Unhappy memories of numerous broken composite video cables at school, and spending half your lunchtime trying to get a working picture...
by johnkenyon
Mon Feb 25, 2019 6:18 pm
Forum: off-topic
Topic: Stag Orbit 32 Programmer
Replies: 21
Views: 2849

Re: Stag Orbit 32 Programmer

Mine kept shutting down about 45 seconds after being powered up. Problem was caused by a botched/leaky battery pack. The battery pack died, and electrolyte from the batteries wicked up the lead and rotted the molex contact. It then continued to rot a track on the PCB. Luckily I could trace where it ...
by johnkenyon
Sat Feb 23, 2019 1:11 pm
Forum: wanted
Topic: Off Topic Wanted: Vintage Sound Blaster & Roland MT32
Replies: 3
Views: 234

Re: Off Topic Wanted: Vintage Sound Blaster & Roland MT32

I've got a CT3990 AWE32 PNP...
by johnkenyon
Sat Feb 23, 2019 1:03 pm
Forum: hardware
Topic: Help - scart output
Replies: 6
Views: 319

Re: Help - scart output

Does your scart lead have the required resistors installed?
I'm wondering if the screen is having problems handling the sync signal.
by johnkenyon
Thu Feb 21, 2019 1:22 pm
Forum: hardware
Topic: Sideways Ram
Replies: 23
Views: 643

Re: Sideways Ram

What Roms/utils do I need to get sideways rom/ram working? *ROMS doesn't work for me at all. *SRLOAD doesn't either. I've got a Watford Electronics 12 ROM board with RAM in position 14. Aside: It's also got provision for a solder-on battery. I have no idea what voltage it needs to be (the instructi...
by johnkenyon
Mon Feb 18, 2019 2:47 pm
Forum: hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 373

Re: i-Cubed EtherLan 500 circuit diagram or good photo

Great, thank you for all the replies - that's really helpful, and I think with a combination of the data sheet, the better photo and a general knowledge of how Ethernet transceivers behave I should be able to get the values right. The extra components look like they're just decoupling for the trans...
by johnkenyon
Sun Feb 17, 2019 4:05 pm
Forum: hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 373

Re: i-Cubed EtherLan 500 circuit diagram or good photo

More digging. The MX98902 is equivalent to the NS83902. The only thing I can find which uses the NS83902 is an IBM "PPC403GCX Evaluation Board". If you can find the documentation for that board, you might also get a schematic thrown in for free. Details of the HALO FD12-101G magnetics can be found a...
by johnkenyon
Sun Feb 17, 2019 3:07 pm
Forum: hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 373

Re: i-Cubed EtherLan 500 circuit diagram or good photo

First result after a bit of digging: https://commons.m.wikimedia.org/wiki/File:Acorn_AEH75_Access%2B_A5000_(top).jpg Possibly copied from/originally taken for: http://chrisacorns.computinghistory.org.uk/Network/Pics/Acorn_AEH75_Access+.html Better: http://www.computinghistory.org.uk/det/33963/i-cube...
by johnkenyon
Sat Feb 16, 2019 12:17 pm
Forum: hardware
Topic: My new beeb - A to B? But why no analogue?
Replies: 19
Views: 703

Re: My new beeb - A to B? But why no analogue?

The ADC socket looks like it's been installed and removed.
It's also got a speech synth upgrade installed - TMS5220 + TMS6100.
by johnkenyon
Wed Feb 13, 2019 7:05 pm
Forum: general
Topic: Today I received.....
Replies: 5233
Views: 388797

Re: Today I received.....

What is it? What does it do? Enquiring minds want to know! This enquiring mind also wants to know :lol: No software or documentation as of yet... The TMS320 is a series of digital signal processors. (aka DSP) You've probably bought yourself a programmable audio filter. You'll have fun getting that ...
by johnkenyon
Sun Feb 03, 2019 12:27 pm
Forum: hardware
Topic: Tube port fault?
Replies: 7
Views: 395

Re: Tube port fault?

Hello again! No news 'till today. I replaced the near 6522 but with no result. I unplugged all the eproms except from Basic and OS, i placed a NFS(I tried also a DNFS eprom) eprom, but with no avail. I get the same symptom when i just plug the flat cable. What i am trying to do, is to use a PiTubeD...
by johnkenyon
Wed Jan 30, 2019 11:34 am
Forum: hardware
Topic: Issue 6 Acorn Electron
Replies: 17
Views: 718

Re: Issue 6 Acorn Electron

I wonder if it would be possible to install this mod internally, by removing R45, R46, R47, connecting the left hand pad (on the schematic, the one connected to the ULA) to the gate inputs, and the outputs to the right hand pad, through some replacement 68R resistors. You would of course need flyin...
by johnkenyon
Sun Dec 02, 2018 5:47 pm
Forum: hardware
Topic: Loss of output on Electron RGB Port
Replies: 24
Views: 654

Re: Loss of output on Electron RGB Port

1024MAK wrote:
Sun Dec 02, 2018 5:43 pm
By default, both the BBC B and the Electron only output a monochrome (black and white) video signal on the composite video outputs.

Mark
Fitting LK4 should add chroma to the video output.
by johnkenyon
Sat Dec 01, 2018 12:36 am
Forum: hardware
Topic: Econet clock?
Replies: 15
Views: 677

Re: Econet clock testing...

Using *notify I tried to send a message across, but no luck. :? Should this work or is a socket box needed for this setup? Have you got NOTIFY on disk or in ROM? ... It seems I may have the basics wrong. I (probably wrongly) assumed that *notify was an NFS command contained in the NFS rom. *help is...
by johnkenyon
Sat Nov 24, 2018 1:38 pm
Forum: wanted
Topic: DS3691 RS423 Line Driver
Replies: 2
Views: 246

Re: DS3691 RS423 Line Driver

Have you googled for AM26LS30 which AFAIK is the same part/pin compatible?
by johnkenyon
Tue Nov 20, 2018 11:28 am
Forum: hardware
Topic: Econet clock?
Replies: 15
Views: 677

Re: Econet clock?

Looking at the other side of the pcb it seems there are even more similarities. Looks like someone's brewed copied the original clock PCB, added a track to permanently select one speed and left the link holes undrilled. I love the way the tracks from the transformer secondary pass oh so close to th...
by johnkenyon
Thu Oct 25, 2018 9:54 am
Forum: hardware
Topic: BBD B+ Issues..please help
Replies: 24
Views: 1011

Re: BBD B+ Issues..please help

Elminster wrote:
Thu Oct 25, 2018 8:19 am
Could be a crack track or a cold joint, that could cause intermit/self fixing issue.
Or a socketed device being moved microscopically in a tarnished socket by contraction/expansion?
by johnkenyon
Fri Oct 19, 2018 10:38 am
Forum: hardware
Topic: PCF8583 breakout board
Replies: 7
Views: 482

Re: PCF8583 breakout board

For the through hole Archimedes machines, I designed this a couple of years ago. https://stardot.org.uk/forums/viewtopic.php?f=16&t=10968 It simply, replaces a borked through hole version with a SMT version of the same chip and provides I2C as a breakout. It does depend on the basic functionality o...
by johnkenyon
Thu Oct 18, 2018 6:10 pm
Forum: hardware
Topic: PCF8583 breakout board
Replies: 7
Views: 482

Re: PCF8583 breakout board

A bit like this - http://www.cjemicros.co.uk/micros/individual/newprodpages/prodinfo.php?prodcode=CJE-RTCPOD ?? I was thinking something a bit more generic/"maker"/arduino/RPi-ish. Preferably using a CR2032 (and no charging) or having two pads to connect to an "off board", out of harms way AAA base...