Search found 248 matches

by johnkenyon
Thu Feb 21, 2019 1:22 pm
Forum: 8-bit acorn hardware
Topic: Sideways Ram
Replies: 23
Views: 1577

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: 32-bit acorn hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 867

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: 32-bit acorn hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 867

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: 32-bit acorn hardware
Topic: i-Cubed EtherLan 500 circuit diagram or good photo
Replies: 7
Views: 867

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: 8-bit acorn hardware
Topic: My new beeb - A to B? But why no analogue?
Replies: 30
Views: 2467

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: 5988
Views: 613218

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: 8-bit acorn hardware
Topic: Tube port fault?
Replies: 7
Views: 881

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: 8-bit acorn hardware
Topic: Issue 6 Acorn Electron
Replies: 17
Views: 1593

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: 8-bit acorn hardware
Topic: Loss of output on Electron RGB Port
Replies: 24
Views: 1469

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: 8-bit acorn hardware
Topic: Econet clock?
Replies: 15
Views: 1402

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: 454

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: 8-bit acorn hardware
Topic: Econet clock?
Replies: 15
Views: 1402

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 10:54 am
Forum: 8-bit acorn hardware
Topic: BBD B+ Issues..please help
Replies: 24
Views: 1991

Re: BBD B+ Issues..please help

Elminster wrote:
Thu Oct 25, 2018 9:19 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 11:38 am
Forum: 32-bit acorn hardware
Topic: PCF8583 breakout board
Replies: 7
Views: 1008

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 7:10 pm
Forum: 32-bit acorn hardware
Topic: PCF8583 breakout board
Replies: 7
Views: 1008

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...
by johnkenyon
Thu Oct 18, 2018 2:44 pm
Forum: 32-bit acorn hardware
Topic: PCF8583 breakout board
Replies: 7
Views: 1008

PCF8583 breakout board

Given the number of A5000's (and others) suffering from battery damage near the RTC chip, wouldn't it make more sense to remove the goosed device from the motherboard and then wire in a "PCF8583+crystal+coin cell battery" on a board. You might even be able to get away with connecting it to the i2c i...
by johnkenyon
Tue Oct 16, 2018 10:37 am
Forum: 8-bit acorn hardware
Topic: BBD B+ Issues..please help
Replies: 24
Views: 1991

Re: BBD B+ Issues..please help

OK... I think I found something. I hooked up my logic analyser to IC30 and I can see the following data on the outputs: That seems to indicate that the 3rd bit is stuck high. The 3rd bit seems to correspond to Q2. Looking at the output of Q2 it starts low, and at power-up it jumps high and just sta...
by johnkenyon
Fri Oct 12, 2018 1:12 pm
Forum: 8-bit acorn hardware
Topic: Master 128 SCART Fun
Replies: 17
Views: 1213

Re: Master 128 SCART Fun

So the idea is that each diode drops about 0.65Vs? Wouldnt you traditionally use a zenner to clamp the voltage instead? You traditionally use what's in your spares box first. For me, 1N4148 diodes, generic small signal NPN (e.g. BC109, 2N2222 etc), and PNP (e.g. BC179, 2N2907) transistors are all "...
by johnkenyon
Tue Sep 25, 2018 11:31 am
Forum: 8-bit acorn hardware
Topic: New econet setup
Replies: 89
Views: 6543

Re: New econet setup

The BBC B library should go to $.LIBRARY The Master library files should go in $.LIBRARY1 If you're copying from an ADFS utilities/fs disc, it's a one for one copy - $.LIBRARY to $.LIBRARY Note that you will have to change the access rights on these files - by default they will probably be WR/, henc...
by johnkenyon
Tue Sep 25, 2018 10:33 am
Forum: 8-bit acorn hardware
Topic: New econet setup
Replies: 89
Views: 6543

Re: New econet setup

The "Bad command" is because you don't have the "FS" command in the library directory on the file server. If you were using a Master 128 as a client, you wouldn't see this, because FS is built in to ANFS. The simple fix for all this is to hit return when prompted for the file server number. This has...
by johnkenyon
Tue Sep 25, 2018 2:59 am
Forum: 8-bit acorn hardware
Topic: New econet setup
Replies: 89
Views: 6543

Re: New econet setup

You entered 0 for the file server - you should have entered 254.
by johnkenyon
Wed Sep 19, 2018 3:37 pm
Forum: 8-bit acorn hardware
Topic: New hardware suggestion - Pi econet server
Replies: 51
Views: 4665

Re: New hardware suggestion - Pi econet server

I would suggest taking the circuit diagram for the Master Econet module, and replacing the ADLC with a bit banging Pi Zero. That would require 3 inputs: clock, data in, "clock present", and two outputs: Data out, and transmit driver enable. There is a lot of circuitry relating to collision detectio...
by johnkenyon
Tue Sep 18, 2018 7:12 pm
Forum: 8-bit acorn hardware
Topic: New econet setup
Replies: 89
Views: 6543

Re: New econet setup

My Master is going to be the file server. Does it matter what its station number is? Are there reserved numbers that should be used for the file store? I have downloaded a bunch of econet docs but only skim read them so far. Usual practice back in the day was to use station 254 for the 1st file ser...
by johnkenyon
Mon Sep 17, 2018 11:42 am
Forum: 8-bit acorn hardware
Topic: New hardware suggestion - Pi econet server
Replies: 51
Views: 4665

Re: New hardware suggestion - Pi econet server

Following the famous phrase ‘if in doubt add another Pi’ could you put a Pi zero in a box with level shifters etc. and an econet connecter and use this purely to bit bang? It would take in raw econet data and convert it to something that the Pi server could use. It would also take meaningful data f...
by johnkenyon
Fri Sep 07, 2018 1:07 am
Forum: 8-bit acorn hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 290MHz)
Replies: 1268
Views: 165474

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Quick question - is the serial debugging linux based? Call me mad but I have this idea to use a 3B+ for the co-pro and also stick a ZeroW in there (maybe a Zero and a Zero W?), all powered by the master and just SSH to the 0W for debugging sessions. I guess it would make sense to mount a double pol...
by johnkenyon
Thu Sep 06, 2018 11:40 am
Forum: 8-bit acorn hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 290MHz)
Replies: 1268
Views: 165474

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Received my PiTubeDirect(s) yesterday and am really happy with them so far, thanks to everybody involved for making this happen. I have one simple question/concern - when I set up the cmdline file so that it defaults to the copro on (at 0 say), it cold starts fine, without needing to press break or...
by johnkenyon
Sat Aug 25, 2018 7:42 pm
Forum: 32-bit acorn hardware
Topic: New A3000 4MB memory
Replies: 75
Views: 7094

Re: New A3000 4MB memory

Are any 72pin SIMMs electrically compatible? Fast Page Mode (FPM) should be. Since the A3000 doesn't interleve memory banks EDO _might_ work in it too. I have some EDO I might try it on a board just for kicks. The reason I asked was because I've got a load of 72pin 4Mb SIMMs sat in a box and this l...
by johnkenyon
Sat Aug 25, 2018 2:10 pm
Forum: 32-bit acorn hardware
Topic: New A3000 4MB memory
Replies: 75
Views: 7094

Re: New A3000 4MB memory

Are any 72pin SIMMs electrically compatible?

/John
by johnkenyon
Fri Aug 24, 2018 6:27 pm
Forum: other vintage hardware, software and languages
Topic: Caution: Latest TL866A/CS firmware can brick programmer
Replies: 28
Views: 8137

Re: Caution: Latest TL866A/CS firmware can brick programmer

His videos have a lot of NSFW language. Swearing and some racist/sexist outbursts. The forum is pretty much the same. Just in case anyone is browsing from work like I do sometimes. I've watched a few of his video blogs and he seems to be a bit loud/gobby, and not particularly funny which puts me of...
by johnkenyon
Fri Aug 24, 2018 12:25 pm
Forum: other vintage hardware, software and languages
Topic: Caution: Latest TL866A/CS firmware can brick programmer
Replies: 28
Views: 8137

Re: Caution: Latest TL866A/CS firmware can brick programmer

kuro68k wrote:
Thu Aug 23, 2018 3:31 pm
Thanks for that, I'll avoid upgrading.

Direct link to the download: https://www.dropbox.com/s/330bs8t4uucnyi9/TL866.zip

EEVBlog is NSFW and the owner has been known to dox people, so better to avoid it and use the direct link if you can.
Never seen any NSFW stuff on the forums.

/John

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