Search found 19 matches

by Volhout
Fri Jul 09, 2021 10:42 am
Forum: acorn atom and acorn system series
Topic: EF9345 based video card
Replies: 23
Views: 667

Re: EF9345 based video card

daveejhitchins wrote:
Fri Jul 09, 2021 8:46 am
And, the module schematic.
IMG_1407.jpg


Dave H.
Wauw, nice to see the whole video is build up with discrete circuits. Sync, backporch, color burst, even the PAL (Phase Alternation) per line with a flipflop on HSync and an EXOR. Great !!.
by Volhout
Tue Jan 26, 2021 9:15 pm
Forum: acorn atom and acorn system series
Topic: Replica Atom
Replies: 88
Views: 11060

Re: Replica Atom

When you can lay your hands on a atom case, there are companies that create a rubber mould from that case, and can pour a copy. Up to 20 cases typically can be drawn from a mould, depending the complexity. But you should expect a price of 100 euros per case. And you can choose a colour, but after co...
by Volhout
Tue Nov 10, 2020 2:44 pm
Forum: acorn atom and acorn system series
Topic: Nice ATOM for sale on eBay
Replies: 7
Views: 727

Re: Nice ATOM for sale on eBay

GBP 1111
Think so ...
by Volhout
Tue Jul 14, 2020 8:30 pm
Forum: acorn atom and acorn system series
Topic: Screen collapse of the Atom
Replies: 20
Views: 1659

Re: Screen collapse of the Atom

Hi, Despite the fact that you are all looking for problems in the digital domain, this can very well be a problem with the analog video output circuit. Maybe the TV/digitizer cannot recognize the horizontal sync signal. It would be good to get a picture (oscilloscope picture) of the video signal. Th...
by Volhout
Tue Jul 07, 2020 12:32 pm
Forum: acorn atom and acorn system series
Topic: Yarrb - redesigned
Replies: 288
Views: 24256

Re: Yarrb - redesigned

Hi anigtin,

That is a big monitor !! With the ATOM graphical resolution you won't need glasses until you're 104 years old...
But I prefer this over the small mobile phone screens that are barely readable at more than 10 inch distance.
Lucky you !

Volhout
by Volhout
Mon Jul 06, 2020 8:31 am
Forum: acorn atom and acorn system series
Topic: Connect a 80287 to a 6502 computer?
Replies: 12
Views: 1365

Re: Connect a 80287 to a 6502 computer?

I know that for the PICAXE microcontroller, there is a floating point co processor in a DIP-8 package.

Volhout
by Volhout
Fri Jul 03, 2020 8:28 am
Forum: acorn atom and acorn system series
Topic: MC6847 video board for Atom 2k15
Replies: 16
Views: 1606

Re: MC6847 video board for Atom 2k15

Maybe adding a pullup resistor to U7 pin 5 helps...

Volhout
by Volhout
Wed Jul 01, 2020 1:07 pm
Forum: acorn atom and acorn system series
Topic: Atom and FPGA based retro-computers
Replies: 75
Views: 12632

Re: Atom and FPGA based retro-computers

It is not FPGA based, it has a STM32H743 480MHz ARM based MCU.
by Volhout
Tue Apr 21, 2020 8:07 am
Forum: acorn atom and acorn system series
Topic: Knotty Atom problem
Replies: 23
Views: 1735

Re: Knotty Atom problem

Exactly the same problem with this ROM in my Replica Atom board. That means that both my real Atoms came with dodgy ROMs. That is very weird. 2 40 year old ROM's with exactly the same problem. If the ROM is defective, but measures correct on the eprom programmer, it may be that your ATOM is the cau...
by Volhout
Wed Apr 01, 2020 2:39 pm
Forum: acorn atom and acorn system series
Topic: Atom tapes with non standard formats
Replies: 37
Views: 3001

Re: Atom tapes with non standard formats

All, Higher data rates are possible using different modulation methods. The ATOM hardware restricts the choice of methods, since there is no way to retrieve information in the signal amplitude. Only the frequency (time) can be used. The COS uses dual tone modulation, where the higher frequency is se...
by Volhout
Wed Mar 18, 2020 1:59 pm
Forum: acorn atom and acorn system series
Topic: Re: ROM IC24 Acorn Atom #A000-#AFFF
Replies: 26
Views: 2241

Re: ROM IC24 Acorn Atom #A000-#AFFF

Ha Jan, That is how I remember it. !!! You have to build an eprom programmer, before you can go to the next level. Program the ROM from BASIC, I was happy to have a 12k machine, so basic program and the 4k image could fit in RAM. Those where the days..... My first ROM was P-Charme. Good memories... ...
by Volhout
Wed Jan 29, 2020 12:10 pm
Forum: acorn atom and acorn system series
Topic: New Atom owner
Replies: 10
Views: 1252

Re: New Atom owner

Nice,

In the video secton you have TC5514's (CMOS rams) that will definitely lower the power consumption.

Volhout
by Volhout
Sun Jan 05, 2020 10:31 pm
Forum: acorn atom and acorn system series
Topic: Atom and FPGA based retro-computers
Replies: 75
Views: 12632

Re: Atom and FPGA based retro-computers

Using the up5k evb board from Lattice i have clean video output and SDDOS working too. So in short: the lattice up5k is capable of housing a full Acorn ATOM with sufficient I/O and memory. That means: - it is possible to have all logic and RAM in one chip costing only 6.70 euro's. - There is 39 I/O...
by Volhout
Fri Jan 03, 2020 6:58 pm
Forum: acorn atom and acorn system series
Topic: Atom 2k18 ?
Replies: 326
Views: 35615

Re: Atom 2k18 ?

Hi roland,

I did not receive your email.

Volhout
by Volhout
Wed Jan 01, 2020 9:07 pm
Forum: acorn atom and acorn system series
Topic: Atom 2k18 ?
Replies: 326
Views: 35615

Re: Atom 2k18 ?

Dear Roland, I looked at the 2k18 board you designed: impressive piece of work. I looked at your 2K18 board layout, and you explained that you put U1 (the fast RAM) under the GODIL so the tracks are shorter. That is fully correct, however... the total track length is significant, and there is no imp...
by Volhout
Wed Jan 01, 2020 9:16 am
Forum: acorn atom and acorn system series
Topic: Atom 2k18 ?
Replies: 326
Views: 35615

Re: Atom 2k18 ?

Hi Roland, Ill check marktplaats once in a while. I will not play with the emulator, since my intentions with the atom are not in games. I am more into building and designing electronics. My atom was almost virgin(1k+1k), except that it had a second main board, that was as big as the atom one, conne...
by Volhout
Wed Jan 01, 2020 8:59 am
Forum: acorn atom and acorn system series
Topic: Replica Atom
Replies: 88
Views: 11060

Re: Replica Atom

Please, for mij curiousity, If you design a new main board for an atom, and want to stay as close as possible to the original.... Why dont you fix the only bug Sophie left in there...? The video noise fixer, is something that I would implement on that board. It simply fixes a timing issue, with abso...
by Volhout
Tue Dec 31, 2019 8:30 am
Forum: acorn atom and acorn system series
Topic: Atom 2k18 ?
Replies: 326
Views: 35615

Re: Atom 2k18 ?

Hi 2k18 designers and builders. Ive been snooping around this forum for some hours, and my old memories came back. Ive not been 10 years away, but more like 30. Years ago i was member of the atom club, region Twente in Netherlands. With the memories, the desire to join you guys in your neverending q...

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