Search found 2673 matches

by Prime
Tue Mar 19, 2019 6:19 pm
Forum: other vintage computer hardware, software and games
Topic: 6847 question.....
Replies: 2
Views: 74

6847 question.....

Hi all, As I'm simultaniously working on both the AtomColour and the DragonRGB, which have a lot in common. On the Atom I'm just taking the Y input from the onboard two transistor Amplifier, and feeding it into Hoglet's clamping circuit and that seems to work quite well. On the Dragon I have had to ...
by Prime
Tue Mar 19, 2019 9:37 am
Forum: hardware
Topic: 3.5" drive for Slogger Pegasus
Replies: 5
Views: 160

Re: 3.5" drive for Slogger Pegasus

danielj wrote:
Mon Mar 18, 2019 8:58 pm
Should do, yes. Or you can use any PC floppy drive (you might have to change the jumper - sometimes a 0ohm resistor - to make it drive 0 though!)
Or use a cabe with a twist between pin 10and 12.....note not the same twist as a PC cable, but works the same way.

Cheers.

Phill.
by Prime
Tue Mar 05, 2019 2:40 pm
Forum: acorn atom and system
Topic: System Clone design files....
Replies: 8
Views: 518

Re: System Clone design files....

bprosman wrote:
Tue Mar 05, 2019 10:26 am
Hi Phill,

What toolchain do you use to compile the Keyboard (AVR) files ?
Atmel Studio ? Or "native" AVRgcc ?
Usually the AVRgcc toolchain, I'm on windows so I (historically) installed WinAVR, and then updated it with the more recent Atmel command line package.

Cheers.

Phill.
by Prime
Sun Mar 03, 2019 11:56 pm
Forum: acorn atom and system
Topic: System Clone design files....
Replies: 8
Views: 518

Re: System Clone design files....

ask_nz wrote:
Sun Mar 03, 2019 6:49 pm
Hi Phil,
*COUGH* Phill *COUGH*
What do you use to program your CPLDs?
Xilinx webpack and one of the clone Xilinx usb programmers like the one shown on hoglet's wiki page here : https://github.com/hoglet67/AtomBusMon/ ... requisites

Cheers.

Phill.
by Prime
Thu Feb 28, 2019 4:51 pm
Forum: acorn atom and system
Topic: Just bought an Atom
Replies: 39
Views: 1145

Re: Just bought an Atom

Looks good, you have : 6K of CPU RAM, 2K of video RAM, Both integer & floting point ROMS. You don't have the printer port, bus buffers or 6522 fitted. And it looks like someone tried ignoring the advice in the Dragon manual not to feed coputers Tea and Coffee....... You do have the video header fitt...
by Prime
Tue Feb 26, 2019 4:16 pm
Forum: off-topic
Topic: LOLPRICE
Replies: 2893
Views: 247806

Re: LOLPRICE

And the award for the most expensive Electon system goes to :

https://www.ebay.co.uk/itm/lolprice/254109643297

Phill.
by Prime
Mon Feb 25, 2019 1:30 am
Forum: acorn atom and system
Topic: Just bought an Atom
Replies: 39
Views: 1145

Re: Just bought an Atom

roland wrote:
Sun Feb 24, 2019 7:35 pm
don't worry, Atom parts are easy to get and quite cheap. As long as the main board is in good condition all will be fine :D
Seconded all reasonably standard chips, weirdest ones are the 8304 and 81LS95, though I think the beeb also uses the latter.

Cheers.

Phill.
by Prime
Fri Feb 22, 2019 9:43 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

Awesome stuff! Does your board have a place for an external character eprom? The version on FB doesn't as it's actually just the Atom board re-purposed....but the Dragon specific version will....first spin currenly on order. I did also considder this for the Atom version, but needing to fit it insi...
by Prime
Fri Feb 22, 2019 8:57 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

And now the Atom board is working in the Dragon.....

https://www.facebook.com/media/set/?set ... c310b7126f

Album should be visible to all even without a FB account.

Cheers.

Phill.
by Prime
Thu Feb 21, 2019 3:26 pm
Forum: other vintage computer hardware, software and games
Topic: The 8-Bit Guy's new 65816 based computer
Replies: 21
Views: 1011

Re: The 8-Bit Guy's new 65816 based computer

My first comment on the joysticks and using NES/SNES sticks, yep it may save you on I/O but at the expense of added complexity and severly limiting what is available to the end user. If you want to limit the I/O used mux the two ports and use the Sega Megadrive scheme which essentially muxes the add...
by Prime
Thu Feb 14, 2019 9:42 am
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

DutchAcorn wrote:
Thu Feb 14, 2019 5:19 am
This looks really good! I’ll get my Atom out over the weekend and see if I can also remember how to program the video card... :D
Be careful, the above posted firmware is for the 5.10 board, but if you have one of those you should be good to go.

Cheers.

Phill.
by Prime
Thu Feb 14, 2019 9:41 am
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

...it worked! I remember being really surprised the first time, because out of a set of controls that look like they might drive a nuclear power station, you click on one and it pretty much instantly completes the job! Yeah the Xilinx software is a little like that, what is a reall pain in the ass ...
by Prime
Wed Feb 13, 2019 2:13 pm
Forum: general
Topic: Bit of fun Part Two - CPU Swap
Replies: 28
Views: 748

Re: Bit of fun Part Two - CPU Swap

Or a 6309, which is a 6809 on steroids! From our benchmark on the Dragon Archive (see http://archive.worldofdragon.org/phpBB3/viewtopic.php?f=5&t=5567&hilit=6309#p17017 ), the 6309 is roughly 3 to 4 times faster computing Pi digits. 3 to 4 times faster than the 6809? Mind doen't supprise me as it d...
by Prime
Wed Feb 13, 2019 11:25 am
Forum: general
Topic: Bit of fun Part Two - CPU Swap
Replies: 28
Views: 748

Re: Bit of fun Part Two - CPU Swap

I always thought, looking at the Tatung Einstein, that it was strongly inspired by the BBC, both in the connectors available and the naming of some of them. It of course runs on a Z80. Now how about a 6809 based beeb? Basically the same bus so a lot of the electronics could be the same, but without ...
by Prime
Tue Feb 12, 2019 8:22 pm
Forum: hardware
Topic: Beeb lid never screwed on. Just me?
Replies: 14
Views: 461

Re: Beeb lid never screwed on. Just me?

Beebs, Atoms, Dragons, actually a couple of my QLs don't have the top half screwed on either.......Neither does the Nascom, but it didn't have any screws when I bought it so that kinda doesn't count.....

Starting to see a pattern here......

Cheers.

Phill.
by Prime
Mon Feb 11, 2019 9:42 pm
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

Hi all,

If you have the ability to re-program the CPLD, then try this set of firmware it hopefully will fix the sync issues in the 5.10 board.

I've tested with Acornsoft Invaders & Flappy bird, and both seem fine.

Let me know how you get on.
AtomColour-5.10-2019-02-11.zip
AtomColour 5.10 CPLD firmware.
(763.06 KiB) Downloaded 11 times
Cheers.

Phill.
by Prime
Mon Feb 11, 2019 7:32 pm
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

This is all sounding very encouraging. Hopefully so.... On my machine one of the most badly-affected games is Flappy Bird, which is colour. If the problem really is noise, what could the mechanism be for generating more noise when running specific games I wonder? I'll give flappy bird a try, does i...
by Prime
Mon Feb 11, 2019 6:42 pm
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

Right, I've tried the syncronous reset and it seems (crosses fingers) to be much better, though I've gone back to counting HS pulses. I'm sure this was the way it was origionally, however I've since implemented a 2 stage latched /hs and am using that as the clock for counting the pulses, as that's w...
by Prime
Mon Feb 11, 2019 3:41 pm
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

Re: AtomColour sync problems, tearing my hair out with this :(

screen.png This is my scope trace of what is happening. 1:Yellow is latched HS xor FS 2:Cyan is the FS input. The scope is set to trigger on the falling edge of this signal 3:Magenta is the HS input 4:Blue is the generated sync signal. This sync is in the approx correct** place, when the problem oc...
by Prime
Mon Feb 11, 2019 11:52 am
Forum: acorn atom and system
Topic: AtomColour sync problems, tearing my hair out with this :(
Replies: 32
Views: 731

AtomColour sync problems, tearing my hair out with this :(

Hi all, I'm really stuck with this, there is a problem with the AtomColour 5.x boards where the sync is lost momentarally leading to the video image jumping. I generate the sync in the CPLD and have tried two methods so far both of which seem to exhibit this problem. Method 1: Wait for /FS to go low...
by Prime
Mon Feb 11, 2019 11:36 am
Forum: upcoming and recent events & exhibitions
Topic: Wakefield RISC OS show 27/4/19
Replies: 68
Views: 1827

Re: Wakefield RISC OS show 27/4/19

flaxcottage wrote:
Wed Feb 06, 2019 1:01 pm
If I can get the demo set up in time I'll also bring a Plotmate A4 set up and LOGO.
Wonder if anyone will use it to draw a giant willy :) I was kinda surpprised no one did that when we where playing with turtles a couple of years back :)

Cheers.

Phill.
by Prime
Wed Feb 06, 2019 7:51 pm
Forum: upcoming and recent events & exhibitions
Topic: Wakefield RISC OS show 27/4/19
Replies: 68
Views: 1827

Re: Wakefield RISC OS show 27/4/19

I might be persuaded if there will be beer the night before......
And assuming it doesn't clash with my other event in April.

Cheers.

Phill.
by Prime
Tue Feb 05, 2019 6:21 pm
Forum: off-topic
Topic: New use for an Electron.......
Replies: 13
Views: 460

Re: New use for an Electron.......

Kazzie wrote:
Tue Feb 05, 2019 3:20 pm
Whatever the suffering of the Electron, that ZX81 now has a much nicer keyboard fitted to it.
Now if only I could get my model M working with my ZX81.....actually I prolly cood if I made a ZX81 -> PS/2 keyboard interface.....

Cheers.

Phill.
by Prime
Tue Feb 05, 2019 10:08 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

This is not my area, but I know someone who had problems with fast modern RAM (not in an ATOM), because it was fast enough to interpret noise as signals that the older RAM didn't seem to notice. That's the reason that I've had to implement a write strobe gate, as when the 6502 was de-selecting the ...
by Prime
Tue Feb 05, 2019 9:29 am
Forum: off-topic
Topic: New use for an Electron.......
Replies: 13
Views: 460

Re: New use for an Electron.......

It's a ZX81! Surprisingly, the Elk's keyboard matrix is almost the same as the ZX series (ignoring the extra keys). So, just a little surgery would move the ENTER, Shift and SPACE keys I did wonder about that there are some pictures in the auction of the underside of the keyboard and I was surppris...
by Prime
Tue Feb 05, 2019 9:24 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

Are you sure it's Acornsoft Invaders because there was a glitch in Bug Byte Invaders: https://stardot.org.uk/forums/viewtopic.php?f=44&t=7320&p=112775&hilit=invaders+glitch#p112775 Seems that during keyscan, the mode is switched to CLEAR0 for a few msec. Yep that could screw things up :( But later ...
by Prime
Tue Feb 05, 2019 9:21 am
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

I wonder if you are getting brief periods of bus conflict between the RAM and IC29 (the 8304 buffer). That is possible, expecially with my write gating activated, but it does it even when just using the /WE pin from the RAM socket. I am planning to maybe also drive /OE from the CPLD, so that /OE is...
by Prime
Mon Feb 04, 2019 10:16 pm
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

jms2, What RAM chip is on your Colour board? Just found something interesting playing with the new version....... With a CY62256 55ns 32K RAM on there I get the problem of the sync jumping about. With a 6264 made by RCA, I think it was harvested off a Slogger Turbo board....thanks Arcadian :) It's a...
by Prime
Sun Feb 03, 2019 6:53 pm
Forum: acorn atom and system
Topic: Atom Colour Board Thread
Replies: 231
Views: 32218

Re: Atom Colour Board Thread

I've done some more investigating on the vsync issue..... No longer seeing it in "Cowboy shootout" but I am seeing it in Acornsoft "Invaders", oddly only when it's in mode 4, and moving the invaders on the screen. Now simultaniously with doing this it will be reading the keyboard and producing sound...