Search found 253 matches

by johnkenyon
Tue Aug 02, 2016 1:48 pm
Forum: 8-bit acorn hardware
Topic: Torch Disk Pack and Z80 co-pro/MCP/CCCP etc
Replies: 15
Views: 2029

Re: Torch Disk Pack and Z80 co-pro/MCP/CCCP etc

This is the thread from 2010 that mentions the cable - http://stardot.org.uk/forums/viewtopic.php?f=3&t=3096&p=25373&hilit=torch+disk+pack Pretty sure the bottom-of-psu plug is the same as the motherboard power plug found on all Apple ][s. The one I'm looking for is an odd 3-pin affair that provide...
by johnkenyon
Mon Aug 01, 2016 6:53 pm
Forum: 8-bit acorn software: other
Topic: Is there an example of how to execut a * command from keybrd buffer
Replies: 12
Views: 1622

Re: Is there an example of how to execut a * command from keybrd buffer

Sorry, guys . . . I may have not explained my requirement (and my ignorance!) correctly . . . . I'm fetching ASCII characters, from a sideways bank, into a string variable. I then need to use the contents of that string variable as a '*command' to launch a Game. An example of how to do this would b...
by johnkenyon
Thu Jul 14, 2016 6:04 pm
Forum: 8-bit acorn hardware
Topic: Master keyboard LEDs
Replies: 3
Views: 682

Re: Master keyboard LEDs

Many moons ago I stripped all the keyswitches and LEDs from my keyborad in order to clean and repair it. I put it all back together except for the LEDs and I's like to fit some but I don't know which ones to buy or which way to fit them. I also wouldn't mind blue rather than red. Anyone know where ...
by johnkenyon
Wed Jun 08, 2016 5:36 am
Forum: 8-bit acorn hardware
Topic: BBC controlled CD Jukebox, great find but need the space!
Replies: 49
Views: 6447

Re: BBC controlled CD Jukebox, great find but need the space!

Looks like what we used to call an Arbiter Jukebox - I worked at Hazel Grove Music who used to make wallboxes, jukeboxes and pool tables in the very early '90s. We produced a version of software for the HGM Mk6 jukebox which would control an Arbiter hideaway. The remote control (two way) from the wa...
by johnkenyon
Fri Jun 03, 2016 6:57 am
Forum: 8-bit acorn hardware
Topic: Updated Beeb PSU
Replies: 53
Views: 6136

Re: Updated Beeb PSU

Going off at a tangent... Thanks John - I did consider the 7v option but given that the two rails are from different PSU units, I wasn't sure whether sinking 60mA (or a bit less at 7v) from the APD into the low-current Casio was a good choice. I reckon the most likely behaviour would be that the Bee...
by johnkenyon
Fri Jun 03, 2016 6:09 am
Forum: 8-bit acorn hardware
Topic: Updated Beeb PSU
Replies: 53
Views: 6136

Re: Updated Beeb PSU

I was on with properly fitting the re-worked PSU when I remembered that I had a miniature 12v fan going spare and since it only draws 60mA, I thought I might as well throw it in there just to move some air around a little which is never a bad thing with PSU's. (I actually added a small series resis...
by johnkenyon
Fri May 13, 2016 5:20 pm
Forum: off-topic
Topic: Compact flash cards....
Replies: 3
Views: 1043

Re: Compact flash cards....

Prime wrote:Hi all,

Does anyone have a good source for smallish CF cards say between 32MB and 1GB? I've looked on ebay but most of them seem to be LOLPRICE :(

Cheers.

Phill.
I have a limited number of 128Mb CF cards spare, PM me with your idea of a sensible price if you're interested.

/John
by johnkenyon
Tue Apr 12, 2016 4:31 pm
Forum: 32-bit acorn hardware
Topic: Acorn 28-AKF17 Monitor
Replies: 27
Views: 3631

Re: Acorn 28-AKF17 Monitor

I think you will find, the latching mechanism is all that has failed. It is a common fault with this type of switch. A lot of TVs and monitors fitted with this style of switch all suffer from this fault. We had a Panasonic TV where the switch failed in exactly the same way. Mark If you have a look ...
by johnkenyon
Mon Feb 01, 2016 5:18 pm
Forum: 8-bit acorn hardware
Topic: Logic analyzer recommendations to help with beeb projects
Replies: 4
Views: 895

Re: Logic analyzer recommendations to help with beeb projects

I have the 8 channel version of this: http://hobbycomponents.com/test/674-hobby-components-cy7c68013a-16ch-logic-analyser which worked fine with the 6MHz system inside my MDFS - it was rather useful for seeing what was going on! I'd have got the 16 channel one if I'd have noticed it. Bargain at the...
by johnkenyon
Sat Oct 10, 2015 12:36 pm
Forum: general
Topic: Today I received.....
Replies: 6056
Views: 640402

Re: Today I received.....

A TRS-80 model 1. Including Expansion Interface and disc drive but no connecting cables. Including 110V and 250V power supplies. The disk drive is 110V. It has seen better days. It also has an extra plug fitted. I would almost assume it is an RGB socket but this is a B&W computer #-o One wire goes ...
by johnkenyon
Wed Sep 02, 2015 9:29 pm
Forum: 8-bit acorn hardware
Topic: master problems
Replies: 29
Views: 3449

Re: master problems

roy bates wrote:nope,cant do anything on the keyboard at all...
Make sure the keyboard is connected correctly - I've had fun and games in the past when I've failed to make sure the keyboard connectors were correctly aligned.
by johnkenyon
Tue Sep 01, 2015 8:29 pm
Forum: 8-bit acorn hardware
Topic: master problems
Replies: 29
Views: 3449

Re: master problems

roy bates wrote:could someone explain how to get the keycaps off before it arrives?
Usual method - remove the lid, and then it's controlled application of brute force via whatever lever comes to hand...
by johnkenyon
Tue Sep 01, 2015 3:51 pm
Forum: 8-bit acorn hardware
Topic: master problems
Replies: 29
Views: 3449

Re: master problems

i have a master 128 coming,and was wondering what could be wrong with it in a general way etc. single long beep and flashing cursor and thats it,nothing else. obviously i dont have it yet and was wondering what areas,ic's to look at when it arrives. acorns are new to me so bare with me.i only have ...
by johnkenyon
Thu Aug 27, 2015 4:03 pm
Forum: 8-bit acorn hardware
Topic: Cleaning a 'cheese wedge'
Replies: 22
Views: 3422

Re: Cleaning a 'cheese wedge'

Hello Retroland! I have recently bought a 6502 co processor (and had it repaired by RetroClinic - thanks Mark!) but wondered if there was any way to remove writing from the surface of the case? Basically it used to belong to some professional establishment of some sort who put their initials on the...
by johnkenyon
Tue Aug 11, 2015 11:07 am
Forum: 8-bit acorn hardware
Topic: BeebMaster clockbox....
Replies: 3
Views: 608

Re: BeebMaster clockbox....

It's a 9V 500mA *AC* adapter (that almost caught me out when I tried to get it working in the US; almost plugged a DC adapter in, which wouldn't have worked so well :-)) A DC adaptor would have worked OK - the clock box has probably got a bridge rectifier and regulator inside. A 9V DC adaptor would...
by johnkenyon
Wed Jul 22, 2015 6:52 pm
Forum: 32-bit acorn hardware
Topic: A3010 Networking (3.10)
Replies: 9
Views: 1289

Re: A3010 Networking (3.10)

You have enabled ipforwarding in the kernel? It's a sysctl option iirc. Steve echo 1 > /proc/sys/net/ipv4/ip_forward will turn it on (until you reboot) http://qcktech.blogspot.co.uk/2012/08/raspberry-pi-as-router.html says you need to edit /etc/sysctl.conf and uncomment the line which says net.ipv4...
by johnkenyon
Wed Jul 22, 2015 6:39 pm
Forum: 32-bit acorn hardware
Topic: A3010 Networking (3.10)
Replies: 9
Views: 1289

Re: A3010 Networking (3.10)

Still no luck - Can ping the Pi but nothing outside the network. Do I need to add any to my Hosts file to route all traffic to the Pi - or should that be taken care of with the nameservers? Have you enabled packet forwarding on the Pi? It is disabled by default. echo 1 > /proc/sys/net/ipv4/ip_forwa...
by johnkenyon
Mon Jun 08, 2015 12:08 pm
Forum: 8-bit acorn hardware
Topic: Master possible short-circuit on main-board
Replies: 20
Views: 2668

Re: Master possible short-circuit on main-board

Ceramic capacitors are normally stable and not likely candidates, but if it has been damaged, yes cut or desolder one leg. Then carry out the resistance test again. Mark Back in the day (early '90s), whilst repairing Z80 based jukebox boards, we had issues with resin dipped ceramic capacitors going...
by johnkenyon
Wed May 27, 2015 12:38 pm
Forum: 32-bit acorn hardware
Topic: RISC PC - Fans
Replies: 15
Views: 3537

Re: RISC PC - Fans

I think I slowed the PSU fan - small circuit with an 7805 sitting on a couple of diode voltage drops. However, I think if I was doing it again, I'd probably do as thedark suggests and get a quiet fan; I vaguely remember that the RiscPC PSU fan may have had one of the mounting lugs removed, so you m...
by johnkenyon
Sun May 10, 2015 9:38 am
Forum: 8-bit acorn hardware
Topic: Model A Linear PSU
Replies: 11
Views: 1917

Re: Model A Linear PSU

It wouldn't surprise me if the power supply had crap regulation.

Or put another way - if you could get the output down to +5v with a small load, I would expect the output to droop to below +5v when connected to the mainboard.
by johnkenyon
Sat Feb 21, 2015 4:10 pm
Forum: 8-bit acorn hardware
Topic: Software won't fit :o(
Replies: 28
Views: 3661

Re: Software won't fit :o(

if your have still trouble lower your page to &1300 or &1100 / with &1100 you can't use some in /out thing on disk The assembler source is probably 4 or 5 times as big as the executable it creates. Personally if it wouldn't fit, I'd split the program in half. One half to assemble the code to run fr...
by johnkenyon
Sat Dec 27, 2014 1:03 pm
Forum: 8-bit acorn hardware
Topic: Setstation not changing my master station number
Replies: 9
Views: 1748

Re: Setstation not changing my master station number

Possibly you've already tried this, but have you got the Tube enabled or disabled when trying to change the station ID? The Tube was enabled and no change to the station number. When it was disabled the number changed. Sir, you are a genius. 8) Coincidentally I discovered this by accident. I found ...
by johnkenyon
Sun Dec 21, 2014 12:13 pm
Forum: 8-bit acorn hardware
Topic: DMA on the Electron
Replies: 14
Views: 3892

Re: DMA on the Electron

Paul, sorry . . . Not heard of DMA 'ever' been used on the Elk Nor can I. Acorn never seemed very keen on DMA. Arguably, they used DMA (of a sort) to allow the video display to share memory but, as I recall, the first production machine that was sold as having DMA was the Risc PC; and even then the...
by johnkenyon
Tue Nov 11, 2014 9:59 am
Forum: off-topic
Topic: Youngsters finding retro "hip"
Replies: 3
Views: 1327

Re: Youngsters finding retro "hip"

flynnjs wrote:I wonder if a Nokia 2110 would still work. IIRC it had a 5v SIM so
I suspect it would blow a modern one up.
I reckon the new SIMs are probably 5v tolerant, so not such a big deal.
by johnkenyon
Wed Sep 10, 2014 1:23 am
Forum: 8-bit acorn hardware
Topic: Acorn Econet Bridge ROM
Replies: 12
Views: 2031

Re: Acorn Econet Bridge ROM

I looked on JGH's site before I posted the question. Couldn't find it :roll: Searching for " econet bridge rom " gives the first match as http://mdfs.net/System/ROMs/Econet/ . ;) The source code hasn't been "installed" in the new web server yet. Note to self - merge JGH's source code with my own di...
by johnkenyon
Tue Sep 09, 2014 5:47 pm
Forum: 8-bit acorn hardware
Topic: Acorn Econet Bridge ROM
Replies: 12
Views: 2031

Re: Acorn Econet Bridge ROM

paulv wrote:Has anyone actually ever imaged this ROM?

Paul
Yes

http://mdfs.net/System/ROMs/Econet/

where you can also find the source code
by johnkenyon
Mon Sep 08, 2014 2:48 pm
Forum: 8-bit acorn hardware
Topic: Beebs and SCSI Hard disks.....
Replies: 74
Views: 15715

Re: Beebs and SCSI Hard disks.....

If you are tempted to try plugging a slightly more modern SCSI drive like the Seagate Hawk 1GB type directly into the Akhter board, be aware of the issue it has with shorting out 0V and +5V on the SCSI connector through the drive. I'll have to check precisely which pin it is when I get home but Bee...
by johnkenyon
Mon Sep 01, 2014 11:06 am
Forum: 8-bit acorn hardware
Topic: Beebs and SCSI Hard disks.....
Replies: 74
Views: 15715

Re: Beebs and SCSI Hard disks.....

The SCSI Parity Enable/Disable option will require a little thought whilst ensuring compatibility with SASI/SCSI1 may best be achieved by 'simply' ensuring that no SCSI-2 commands are used and of course this may not be a trivial exercise. Shirley if the Beeb is acting as an initiator, it will only ...
by johnkenyon
Tue Aug 19, 2014 1:37 pm
Forum: 8-bit acorn hardware
Topic: Worried about my Cub
Replies: 5
Views: 1255

Re: Worried about my Cub

If you want to limit the power going to the VDU (and therefore prevent or limit and damage) when testing it, you could use the trick that TV repair guys use. On the mains voltage side, wire a mains filament light bulb (60W or 100W, try the 60W first) in series with the "line" / "live" / "hot" wire....
by johnkenyon
Sun Aug 10, 2014 10:26 pm
Forum: 8-bit acorn hardware
Topic: Using a 19V DC laptop PSU on an Electron
Replies: 17
Views: 2485

Re: Using a 19V DC laptop PSU on an Electron

jms2 wrote: When I first plugged the PSU into the mains I'm sure I heard a brief 'crack' noise from inside the plug
That be the spark being drawn as the (mains) plug and socket make contact.
The input capacitor of a switch mode PSU means that the initial current draw is very high for a fraction of a second.

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