Search found 800 matches

by flynnjs
Mon May 23, 2011 9:45 pm
Forum: general
Topic: Domesday Reloaded
Replies: 67
Views: 13068

Re: Domesday Reloaded

Yes, I received the board and a few other goodies today. As there is so much interest, I'll reprioritise and do the SCSI board first. I'll try to get my teeth into it tomorrow night. Do we have any idea of how many of these are in demand? I was thinking of etching around 10 boards. Also, do people j...
by flynnjs
Sun May 22, 2011 7:55 pm
Forum: hardware
Topic: Eprom programming voltages...
Replies: 3
Views: 768

Re: Eprom programming voltages...

Typically, non-CMOS units require 21V and CMOS units 12.5V.

27128 c.f 27C128

However, best bet is to check the datasheet first. If unsure
start with 12.5v first.
by flynnjs
Sun Apr 10, 2011 6:22 pm
Forum: hardware
Topic: Music 500(0) schematic
Replies: 12
Views: 2804

Re: Music 500(0) schematic

I've not had any contact about schematics.

However, I've had a PM from a friendly regular on here who is willing to dig out a real unit. I'll buzz it out and recreate a schemaitc from that and post it up in due course.
by flynnjs
Sat Apr 09, 2011 5:19 am
Forum: emulators
Topic: And todays broken pencil award goes to.....
Replies: 14
Views: 3662

Re: And todays broken pencil award goes to.....

The difference between virtualisation and emulation is whether or not a CPU is being emulated. DOSBox emulates the CPU and is, therefore, an emulator. This means it can be ported to other platforms e.g. Sparc. A virtual machine sends the CPU instructions straight through to the host's CPU and so yo...
by flynnjs
Sat Apr 02, 2011 9:54 am
Forum: hardware
Topic: Music 500(0) schematic
Replies: 12
Views: 2804

Music 500(0) schematic

Does anyone have one? I've read the description of how it works and it doesn't seems that complicated and was wondering about building an FPGA based clone.

J
by flynnjs
Fri Mar 11, 2011 7:52 am
Forum: off-topic
Topic: LOL DESCRIPTION
Replies: 612
Views: 68382

Re: LOL DESCRIPTION

I mailed him about getting some photos of the inside. The answer was "I wouldn't like to open it". Makes me a little suspicious, Acorn stuff is *meant* not to have screws in it :lol:
by flynnjs
Wed Mar 09, 2011 7:49 am
Forum: for sale / freebies
Topic: Possible new run of Atom SD card interface boards
Replies: 7
Views: 984

Re: Possible new run of Atom SD card interface boards

Potentially, yes. Depends if I get all the parts to build mine or manage to acquire an Atom to repair.

Any idea where I can get a case?
by flynnjs
Wed Mar 09, 2011 7:36 am
Forum: past events & exhibitions
Topic: Wakefield Acorn Show / 16 April 2011 / W. Yorks
Replies: 47
Views: 5910

Re: Wakefield Acorn Show / 16 April 2011 / W. Yorks

Upgade me from a possible to definite, I've just booked the Friday off work and will travel up Friday!

Now just need to work out what to take with me :-)
by flynnjs
Tue Mar 01, 2011 10:03 pm
Forum: hardware
Topic: Nasty 1MHz bus
Replies: 22
Views: 2290

Re: Nasty 1MHz bus

When I measure the programming voltage at 21V and the input resistance of the VPP pin to gnd I get 6K ohm. When I then put the EPROM in the programmer and switch to program the voltage drops, it gets hot and then when I re-measure the resistance after I've taken it out it's about 1k ohm. Sounds lik...
by flynnjs
Mon Feb 28, 2011 10:57 pm
Forum: acorn atom and system
Topic: Atom upgrades pt 2
Replies: 38
Views: 4369

Re: Atom upgrades pt 2

Mmm, look at those mitred corners. Not one missed! Real pride at work there :)

Jason (an OCD mitrer)
by flynnjs
Fri Feb 25, 2011 3:37 pm
Forum: wanted
Topic: 8255 + other Atom parts
Replies: 4
Views: 686

8255 + other Atom parts

Having obtained RAM, CPU and Video ICs for an Atom I'm now after an 8255 and some of the other bits and bobs. Does 81LS95 have any sane alternatives? I think I can source all the rest of the 74series stuff.
by flynnjs
Tue Feb 22, 2011 7:58 am
Forum: past events & exhibitions
Topic: Wakefield Acorn Show / 16 April 2011 / W. Yorks
Replies: 47
Views: 5910

Re: Wakefield Acorn Show / 16 April 2011 / W. Yorks

I will be at Gadget Show Live with the museum, so I cant attend. (Nor can the museum attend this year.)
Meh, 3 events to go to in one weekend. I might be there :mrgreen:
by flynnjs
Sun Feb 20, 2011 10:27 pm
Forum: past events & exhibitions
Topic: Centre for Com His / TBA 2011 / Haverhill, Suffolk
Replies: 38
Views: 5235

Re: Centre for Com His / TBA 2011 / Haverhill, Suffolk

Hmm, b/hol w/e. Not sure if I'll be able to get there. Anyway, I'll
keep monitoring the thread and flag whether I'm attending in
due course.
by flynnjs
Sun Feb 20, 2011 8:47 am
Forum: hardware
Topic: Simulating a Remote Control
Replies: 15
Views: 1877

Re: Simulating a Remote Control

will a receiver that normally expects modulation to be present be able to decode without it, i.e. just the data? Not usually. Basically, the IR signal is fed through a capacitor to block the DC component caused by ambient light. The carrier passes through this and is then demodulated, sometimes the...
by flynnjs
Sat Feb 19, 2011 11:06 pm
Forum: hardware
Topic: Simulating a Remote Control
Replies: 15
Views: 1877

Re: Simulating a Remote Control

As flynnjs pointed out BTW, I'm Jason :P BeebMaster & SirMorris (amongst others, but I include them as they are vocal on this thread) met me a Bletchley last summer. I'm sure there's plenty of help available to get this remote stuff going but I guess we need a lot more information. Beebmaster has a...
by flynnjs
Sat Feb 19, 2011 9:36 am
Forum: hardware
Topic: Simulating a Remote Control
Replies: 15
Views: 1877

Re: Simulating a Remote Control

The problem with feeding directly into an LED is that background light affects the receiver. This is usually solved by modulating a carrier with the data to be transmitted. Therefore your user port program will need to switch the transmit LED on and off quickly (to create the carrier) and then start...
by flynnjs
Wed Jan 26, 2011 10:38 pm
Forum: acorn atom and system
Topic: Acorn Atom for sale on Ebay
Replies: 7
Views: 1774

Re: Acorn Atom for sale on Ebay

Another one just gone for £144. Given the cost of obtaining the legacy parts to build one these figures aren't unrealistic. :(
by flynnjs
Mon Jan 24, 2011 9:40 pm
Forum: acorn atom and system
Topic: Atom RAM
Replies: 6
Views: 1299

Re: Atom RAM

Not sure I'd desperately want to be flogging 12 though, that's quite a lot.
Indeed. I've got a whole board to populate :-(

There's some MCM2114P45 on e-bay from .nl but only 5pcs left.

I think I'm going to have to splash out on from the USA.
by flynnjs
Sun Jan 16, 2011 9:47 am
Forum: hardware
Topic: Cleaning bbc micro
Replies: 4
Views: 1394

Re: Cleaning bbc micro

Washing the PCB is water should be OK provided you follow Mark's advice to use de-ionised/distilled water leave to dry properly before applying power. However, I wouldn't let it "soak" as there are probably devices that will degrade due to ingress if left for any duration, so just a quick rinse shou...
by flynnjs
Fri Jan 14, 2011 11:49 am
Forum: acorn atom and system
Topic: Atom RAM
Replies: 6
Views: 1299

Atom RAM

Hi all, does anyone have any tips on buying 2114s? I'm aware that the 2114L has lower dissapation and would be preferred for a fully loaded board but are there any brands that have compatibility issues with a regular Atom? I've found Intel, Toshiba, OKI, NatSemi types so far. Finally, is there anyon...