Search found 2712 matches

by Prime
Wed May 15, 2019 10:40 pm
Forum: other vintage computer hardware, software and games
Topic: C64 software....and stuff....
Replies: 7
Views: 355

Re: C64 software....and stuff....

Thanks all, for the game recommendations...... Seems it helps to have a real C64 lead, found the lead I made up a few years ago and labled C64/VIC20 and the video is much better through that get proper (and much brighter) colours and they stay that way. Hopefully the svideo cable will be better stil...
by Prime
Wed May 15, 2019 8:38 am
Forum: other vintage computer hardware, software and games
Topic: C64 software....and stuff....
Replies: 7
Views: 355

Re: C64 software....and stuff....

Thanks for those,

Having played a few games on the machine I found they where all nice and sharp but in greyscale....so I somewhat suspect the current monitor lead is not wired correctly, I've got one on order from ebay along with a couple of the fixers that you linked to.

Cheers.

Phill.
by Prime
Tue May 14, 2019 8:44 am
Forum: other vintage computer hardware, software and games
Topic: C64 software....and stuff....
Replies: 7
Views: 355

C64 software....and stuff....

No that I have my sd2iec & kernal rom switcher working......it would be good to get some software on there to actually play on this machine.... So does anyone know if there's a software collection for the commodore 64 like the STH Beeb or Atom collections? Other thing is the video output on this mac...
by Prime
Sun May 12, 2019 10:49 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 650
Views: 52211

Re: ICE T65/Z80/6809

Does anyone have any success or experience building the target under windows? Andrew from Australia I woorked out how to do this if you have cygwin installed further back up the thread here : https://stardot.org.uk/forums/viewtopic.php?f=44&t=9655&start=570#p186385 Dave, might be an idea to grab th...
by Prime
Sat May 11, 2019 4:25 pm
Forum: software: other
Topic: ROM image disassembly (not on a Beeb).
Replies: 9
Views: 286

Re: ROM image disassembly (not on a Beeb).

I use BeebDis https://github.com/prime6809/BeebDis . An emulator with a debugger built in might help also. The documentation for BeebDis is awful isn't it? It's seemingly written from the point of view of someone who already has in depth knowledge of how the thing works. That's exactly how it's wri...
by Prime
Tue May 07, 2019 8:46 am
Forum: general
Topic: DRAGON USER gripes about the Computer Literacy Programme.....
Replies: 52
Views: 1140

Re: DRAGON USER gripes about the Computer Literacy Programme.....

vanpeebles wrote:
Tue May 07, 2019 8:27 am
I have a megadrive joypad with the dragon logo on the box, did they(or related) move into other stuff?
I have a USB -> IDE case with the Acorn logo on it in much the same way......

i.e. Origional company goes pop, someone buys the ip and uses the logo on their products.

Cheers.

Phill.
by Prime
Thu May 02, 2019 9:28 am
Forum: general
Topic: DRAGON USER gripes about the Computer Literacy Programme.....
Replies: 52
Views: 1140

Re: DRAGON USER gripes about the Computer Literacy Programme.....

The Dragon & CoCo also used a block based tape format, though unlike the beeb they didn't have a block number and the error correction wasn't as good....you couldn't rewind the tape to retry like you could on the beeb, I guess because of the lack of a block counter. As Dragon / CoCo basic is effecti...
by Prime
Tue Apr 30, 2019 8:21 pm
Forum: general
Topic: DRAGON USER gripes about the Computer Literacy Programme.....
Replies: 52
Views: 1140

Re: DRAGON USER gripes about the Computer Literacy Programme.....

Note this isn't specifically aimed at Ramtop, though it's his post I quoted, more of a general reply to this thread..... They're basically a coco - the display is awful (al-la-atom), but the guts aren't too shabby with a 6809? It's quite a poor computer overall, with the exception of the CPU. The gr...
by Prime
Sun Apr 28, 2019 3:30 pm
Forum: acorn atom and system
Topic: Fitting instructions for RAMROm & AtomColour April 2019
Replies: 4
Views: 173

Fitting instructions for RAMROm & AtomColour April 2019

Hi all,

This is mostly for Daniel and Marcus, here are the fitting instructions for the RAMROM and AtomColour boards.
Ram Rom ClockBoost V2x.pdf
RamRom fitting instructions
(41.46 KiB) Downloaded 13 times
Atom Colour V5.x - Copy.pdf
AtomColour fitting instructions.
(80.78 KiB) Downloaded 12 times
Any problems with them please feel free to ask.

Cheers.

Phill.
by Prime
Fri Apr 26, 2019 8:11 am
Forum: acorn atom and system
Topic: Atom colour noise problem.....
Replies: 9
Views: 314

Re: Atom colour noise problem.....

hoglet wrote:
Fri Apr 26, 2019 6:25 am
Those levels look very close to what I measured, assuming that was a green screen (i.e. medium white).
Yeah that was clear 4, displaying the MMC menu.

Cheers.

Phill.
by Prime
Fri Apr 26, 2019 8:04 am
Forum: upcoming and recent events & exhibitions
Topic: Wakefield RISC OS show 27/4/19
Replies: 128
Views: 4254

Re: Wakefield RISC OS show 27/4/19

BTW who's gonna be around for drinks this evening and what time are people getting there?

I would imagine for Lesley and I will be sometime 7.00pm-8.00pm

Cheers.

Phill.
by Prime
Fri Apr 26, 2019 8:03 am
Forum: upcoming and recent events & exhibitions
Topic: Wakefield RISC OS show 27/4/19
Replies: 128
Views: 4254

Re: Wakefield RISC OS show 27/4/19

danielj wrote:
Fri Apr 26, 2019 6:52 am
Mixing it up. No one will notice. Promise. :D
I could bring a Dragon too......

Cheers.

Phill.
by Prime
Thu Apr 25, 2019 10:38 pm
Forum: acorn atom and system
Topic: Atom colour noise problem.....
Replies: 9
Views: 314

Re: Atom colour noise problem.....

I've captured these with the Rigol software, what I have found is that the Rigol tends to read slightly high with respect to both of my multimeters not sure why that is but both my DS1052 and DS1054 do it!
screen1.png
First capture
screen2.png
Second capture.
Cheers.

Phill.
by Prime
Thu Apr 25, 2019 5:11 pm
Forum: acorn atom and system
Topic: Atom colour noise problem.....
Replies: 9
Views: 314

Re: Atom colour noise problem.....

Another quick question. Can you set the threshold pot to the best position, and measure the following: 1. The voltage across C9 (the Y comparator threshold voltage, mine is 1.46v) 2. The voltage across C17 (the back porch clamp level, mine is 0.98v) 1: measured at the pot wiper, 1.27V 2: Measured a...
by Prime
Thu Apr 25, 2019 9:48 am
Forum: acorn atom and system
Topic: Atom colour noise problem.....
Replies: 9
Views: 314

Re: Atom colour noise problem.....

Here's the CPLD files. AtomColour580-2019-04-25.zip I'm only actually using luminence to detect green and buff, so hopefully that shouldn't be a problem, certainly as you also found, detecting the other colours by their AH/AL BH/BL values is much less prone to noise. As for using a separate 3.3V reg...
by Prime
Wed Apr 24, 2019 9:31 pm
Forum: acorn atom and system
Topic: Atom colour noise problem.....
Replies: 9
Views: 314

Atom colour noise problem.....

Hi all, Following on from Hoglet's suggestion in the Noisekiller thread I've broken this into it's own thread. I'm still getting some noise on the display of the new Colour board as displayed in this youtube capture : https://www.youtube.com/watch?v=C5XY52Fh1X4 The first half of the video the atom i...
by Prime
Mon Apr 22, 2019 12:59 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

Welll......none of those things seemed to help :( I've posted a video of the noise I'm getting here : https://www.youtube.com/watch?v=C5XY52Fh1X4 First half of the video is displaying menu with the sta #8000 loop. I then hit break and just boot the mmc, which displays the standard games collection m...
by Prime
Sun Apr 21, 2019 2:23 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

I rather suspect it's noise that's getting onto the Y line, as it only appears in areas of the screen where the Y signal is used. If you change the test program to: [ LDA #8000 JMP #9C00 ] do you still get noise? I'm wondering if during CPU writes there is a brief bus conflict, where momentarily bo...
by Prime
Sat Apr 20, 2019 5:50 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

Right I've done some more playing with my lashup..... For both R/C delay circuits I have used the following values : R = 1.1K C = 27pf Reason being that they give approx the correct delays and the board already has those values elsewhere so helps keep the number of different component values down. I...
by Prime
Sat Apr 20, 2019 5:38 pm
Forum: other vintage computer hardware, software and games
Topic: Apple IIe & Disk II with issues
Replies: 10
Views: 328

Re: Apple IIe & Disk II with issues

The machine is the original model of the IIe, it does not have the 'Enhancement' kit with the 65C02 CPU and new ROMs Once you get it going of course...... You can use the WDC65c02 + programming some Eproms to upgrade to the enhanced version, I've done that with one of my IIe machines. Cheers. Phill.
by Prime
Thu Apr 18, 2019 12:00 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

And I'm sure you meant try increasing R by ~50% to 150R...... Sorry, I ended up changing to using 100pF and 220R (rather than 220pF and 100R). I didn't update the earlier schematic. Anyway, I'm expecting to have to fiddle with the values a bit more. Ahhh so same as on the /WE circuit then :) That's...
by Prime
Thu Apr 18, 2019 9:36 am
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

Looking at the scope trace the total latch time is coming out at around 575ns, the odd thing is if I rest my finger lightly on the R and C the latch time goes up by about 10ns and the snow goes away, so I may need to just adjust the C slightly to slightly lengthen the pulse. It could of course just...
by Prime
Wed Apr 17, 2019 10:55 pm
Forum: upcoming and recent events & exhibitions
Topic: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD - NOW FULLY BOOKED
Replies: 84
Views: 2968

Re: ABUG Cambridge 28th - 30th June 2019 BOOKING THREAD

Also, who's the resident floppy archiver (flaxcottage?). At the moment I think I only have a couple of requests relating to Atom and System, so don't expect to take too much of anyone's time. If you can get a chance any software for the System 6809 card would be good to test my clone out :) I know ...
by Prime
Wed Apr 17, 2019 10:52 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

Ok, So I've tried Dave's circuits on the Mk5.9 board and they apper to mostly be working. The Write pulse shortening circuit works as designed, giving about a 70ns write pulse which should be long enough for 55ns RAM. Modified R/C values would of course be required for slower say 70ns or 100ns, but ...
by Prime
Wed Apr 17, 2019 8:20 am
Forum: hardware
Topic: Last Gasp for the 8271
Replies: 12
Views: 492

Re: Last Gasp for the 8271

Yeah I'd be interested in 2-3 8271s, just as spares for Atom / System. Though for the Atom I did produce a 177x disk interface, so the code for that exists and is as far as I can tell compatible with all the software I've seen as there didn't seem to be much Atom / System software that made direct a...
by Prime
Tue Apr 16, 2019 2:16 pm
Forum: acorn atom and system
Topic: ICET-6809
Replies: 15
Views: 663

Re: ICET-6809

Just to comment, The Dragons in question work as normal with a standard 6809 in them, so hopefully the fault's not there :)

Cheers.

Phill.
by Prime
Tue Apr 16, 2019 8:00 am
Forum: acorn atom and system
Topic: ICET-6809
Replies: 15
Views: 663

Re: ICET-6809

Actually, the lack of a keyboard isn't actually blocking me, as the issue occurs during the startup sequence, or when just idling. A couple of Dragon questions.. When boot and idling, what's actually going on? Are interrupts routinely happening for example? Boot sequence : Init Hardware, PIAs, SAM,...
by Prime
Mon Apr 15, 2019 11:08 pm
Forum: acorn atom and system
Topic: ICET-6809
Replies: 15
Views: 663

Re: ICET-6809

Ok, I tried your updates to the timing, still doesn't seem to improve things. Running through a buffer board (buffering address and data with LS245s), does seem to make some improvement but not much :( One thing I have notice is that often the Dragon will power up with less than 32K of memory availa...
by Prime
Mon Apr 15, 2019 10:59 pm
Forum: acorn atom and system
Topic: Atom Noise Killer @ 2MHz
Replies: 28
Views: 667

Re: Atom Noise Killer @ 2MHz

Right Interesting work there, Will have to try replicating as it would certainly possibly make things easier to not have the 74xx123 in there :) Though the two boards I have ready to go out will go out with that circuit on, as they are being delivered at the Riscos show :) Your findings with relatio...
by Prime
Sun Apr 14, 2019 9:46 pm
Forum: acorn atom and system
Topic: Using PC Floppy Drives ?
Replies: 6
Views: 252

Re: Using PC Floppy Drives ?

(80-track drives outside the PC world are Quad Density, 40-track are Single/Double Density.) That may have been how drive / media manufacturers described things but it's slightly misleading. The single / double density thing is the encoding method of the data, single uses Frequency Modulation (FM) ...