Search found 211 matches

by waltermixxx
Sat Mar 10, 2018 4:20 am
Forum: acorn atom
Topic: What's first...?
Replies: 8
Views: 575

Re: What's first...?

Do post pictures as you go.
The unit, the motherboard,
All the bits. We love to see them.
by waltermixxx
Fri Mar 09, 2018 2:21 am
Forum: acorn atom
Topic: Looky what I found...
Replies: 0
Views: 454

Looky what I found...

Gladstone-Electronics the only place I found that sold the Acorn Atom in Canada. This is where I went to buy my games. This is from May 1983 Electronics Today. Funny, I always thought the store was called Global-Electronics. The brain plays tricks on you.... E3CE57A6-A6E6-48BB-9641-B3EB4D7D72EC.jpeg...
by waltermixxx
Sat Feb 17, 2018 11:09 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Thank you, yes, that's the schematic I will most likely use when I swing around into Acorn Atom mode, currently messing around with a ESP32 based wifi modem for my Commodore 64 and 128. :) it's nice logging into BBS's at 2400 board.

Very nifty indeed. :)
by waltermixxx
Sun Feb 04, 2018 11:29 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

That explains a lot

Cool thank you very much. All is well in Acorn Atom land.

Cheers!!!
by waltermixxx
Sun Feb 04, 2018 4:28 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Here is a snapshot from the scope with colour output and pin 9-10 mono putput.
below that is the image from the TV (using the colour output).

NewFile1.png


AB9C3741-7C67-488C-A4B4-388C5DEED7A5.jpeg


Cheers.
by waltermixxx
Sun Feb 04, 2018 4:13 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Pictures comparing the colour output of the colour board to the monochrome output of the atom on pin 9-10 of video connector. I thought the colour output would be grey scale on a B&W tv, but it appears to be “dotted” like with the Apple II (artifact colour) At any rate here are images from my li...
by waltermixxx
Sun Feb 04, 2018 3:35 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

As stated previously as a kid I never hooked up my Acorn Atom to a colour TV, as a result I’m not sure what looks right. I find in text mode the characters appear as a light green on a much darker green. Is this normal? Also I wonder about some of the text graphics with very black spaces. (Not the s...
by waltermixxx
Sat Feb 03, 2018 11:01 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Yes I am. :) My Acorn Atom is very happy, and so am I. The only thing missing now, really is a noise eliminator. But I will save that for down the road, don't wanna do it all at once. :) It's funny, I'm almost 100% sure the Acorn Atom I had as a kid, did have the colour card, although I don't think ...
by waltermixxx
Sat Feb 03, 2018 9:23 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

I finally added colour to my Acorn Atom. I already had Zippster’s colour computer composite video out board, so I thought may as well try it out. And sure enough it works great. It is NTSC colour which works great for me. The only thing I had to do was remove the two rca jacks on the board as they i...
by waltermixxx
Wed Jan 24, 2018 8:57 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Good point. :)

I hope to get to that some time soon, I still have to record my Acorn Atom experiences for Randy from 1982 when I first brought one home...
a special day indeed.... :)

cheers.
by waltermixxx
Mon Jan 22, 2018 11:15 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

I just plugged my ATOM in without an SD card, and yup after about 18 seconds, i get the Banner, so my previous post was incorrect. Without an SD card, I do get the Acorn Atom + AtomMMC banner, after the usual 18 second delay on a very cold boot. I will try an other sd card, and see if that changes.....
by waltermixxx
Mon Jan 22, 2018 3:26 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Pretty sure Ive checked it without an SD card, and it will not post Acorn Atom + Atommc2.
I will have to try again, to be certain. (memory fading and all...) :) I'm using the A000 version of the rom. :)

I will test tonight, when I get home from work. And test with another SD card as well.

Cheers.
by waltermixxx
Mon Jan 22, 2018 12:00 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

It's time to try a new SD card.

I will follow up when I have a chance.

Thanks again everyone.
by waltermixxx
Sun Jan 21, 2018 6:05 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Is this normal? Pin 5&6 appear to be shorted? (not shorting check between 5 and 6... Pin 6 does not go into the pcboard but curls under, no connection to the pcboard, and no connection from pin 5 to the pcboard. oddly enough there is a connection between pin 6 of the chip to pin 5 of the pcboard...
by waltermixxx
Fri Jan 19, 2018 10:26 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

so, update: i put the DSO on pin 19 (IRQ) and i get a pulse on power on, when the display still says ACORN ATOM. then i set the scope to trigger on a pulse, and watched it to see what happens when the display switches to, ACORN ATOM + ATOMMC2. Nothing coming from IRQ, no pulse when the screen change...
by waltermixxx
Thu Jan 18, 2018 5:44 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

they do their initial blinking on power up.
Pretty sure that is the only time they blink unless there is disk access.
pretty sure it does not blink at the 12 second mark when the heading on the tv changes from Acorn Atom to Acorn Atom + ATOMMC2

I will do more testing. :)
by waltermixxx
Thu Jan 18, 2018 11:35 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

I will have to check. It did this with two separate power supplies. Both at least 2.amp. Both are from name brand devices. The output with no load was about 5.25. I have a Rigol DSO scope, so I can watch the NMI line. The light on the device does flash upon power up. I could try issuing a link comma...
by waltermixxx
Wed Jan 17, 2018 11:24 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Here is a link to the youtube video.
hopefully it shows the issue...

https://www.youtube.com/watch?v=zzgItXsn9x0

no laughing at my commentary ;o)
by waltermixxx
Wed Jan 17, 2018 8:50 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Will do. :)
by waltermixxx
Wed Jan 17, 2018 8:21 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

before I installed the 32k daughter card, no scrambled screen on power up. and i got the Acorn Atom + ATOMMC right away. WIth the 32k ram daughter card I built, still no scrambled screen, just Acorn Atom at the top, with a cursor... and If I do a shift break before 12 seconds have past, I still only...
by waltermixxx
Wed Jan 17, 2018 6:29 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Regarding the 32k memory upgrade, I notice when I turn my Atom on, the screen says Acorn Atom initially, then after about 12 seconds, it changes to Acorn Atom + AtoMMC

Is that delay normal because of the extra ram?
by waltermixxx
Fri Jan 12, 2018 8:07 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Yup saw this: One final note, is that different manufacturers LS/HC/HCT 123 chips have slightly different time constants, and the R and C values have to be calculated from the datasheet of the chip you are using. Cheers. Phill. noisekiller.jpg I know there is a ball park R (8.2k) / C (150pf) to valu...
by waltermixxx
Fri Jan 12, 2018 6:00 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Nice job Walter ..... let the gaming begin ..... =D> The easiest way to add a noisekiller is this one: http://www.acornatom.nl/atom_nieuws/1985/nr3/19853086.htm It also replaces the video buffers with more common 74LS244 and 74LS245 chips. Greetings Kees I was thinking of going this route, once aga...
by waltermixxx
Fri Jan 12, 2018 3:20 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Ok the 32k ram daughtercard is done. :) seems to work fine. 38933202664_d3e30850e9_k.jpg 39641677201_02e630862d_k.jpg 38745358965_a49c04c043_k.jpg Wondering if Colour board should be next, or noise eliminator... I'm thinking noise eliminator, as I dont think I ever used colour as a kid with the atom...
by waltermixxx
Tue Jan 09, 2018 3:50 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Ok progress thus far. 8 address lines and a couple of CS lines to go. I know I'm drawing this out, (This thread, and this little project). But just like a good book, a good little wiring project makes me sad as I near the end. The book because I will miss the characters, and the little wiring projec...
by waltermixxx
Mon Jan 08, 2018 10:03 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Once again. Thank you.

:0)
by waltermixxx
Mon Jan 08, 2018 9:10 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Ok perhaps a goofy question, and perhaps I should have asked before starting to build my very basic 32k ram daughter card. :) I've looked in the Technical Manual, and even Splitting the Atom documentation, and I guess I'm wondering: Once I install the 32K memory and have memory from #0000 to #7FFF, ...
by waltermixxx
Mon Jan 08, 2018 7:20 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Thank you Dave,

Very much appreciated. :)

Cheers. :)
by waltermixxx
Mon Jan 08, 2018 1:06 am
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

I noticed that there were two inverters on pin 39 of the PHI2 pin. Is that used to add a propagation delay or just buffer it (without inverting it)? Would this be ok for my 32k ram upgrade, (this is from Briel's Apple 1 replica) : 32kram.png could i use this as is, or should i add two inverters to t...
by waltermixxx
Sun Jan 07, 2018 11:39 pm
Forum: acorn atom
Topic: My New Acorn Atom :)
Replies: 63
Views: 2877

Re: My New Acorn Atom :)

Because of the vero board I had on hand was only one sided. There was no way to solder the header to the daughter card board to ensure a good solid connection to the Atom. I basically did it with what I had on hand. The 6502 is a spare, i have a few (and it's still working fine) :) The 32kB static r...