Search found 288 matches

by bprosman
Mon Jul 08, 2019 8:47 pm
Forum: hardware
Topic: Addres Decoder calculator. Who knows one ?
Replies: 1
Views: 190

Addres Decoder calculator. Who knows one ?

Years and years ago I used to have a DOS program which was an "Address decoder calculator". You filled in the address range and the calculator gave you the required Address lines as well as the logic equations (that could be fed into a PAL/GAL etc.). But cant find it anymore in my archives. I can do...
by bprosman
Sun Jul 07, 2019 10:32 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 657
Views: 54843

Re: ICE T65/Z80/6809

Today the ICE-T65 was a great help again to get a board running it's 1st program, test the memory and memory decoding.
Processor (program) is nicely looping and debugging.

WHAT A GREAT TOOL !!!

Next step to get some I/O done.
IMG_0542.jpg
IMG_0543.jpg
by bprosman
Sat Jul 06, 2019 9:09 pm
Forum: acorn atom and system
Topic: AtomSID
Replies: 26
Views: 2129

Re: AtomSID

Also curious in (if any) quality differences between a SwinSID and a FPGA-SID
by bprosman
Sat Jul 06, 2019 12:08 pm
Forum: acorn atom and system
Topic: AtomSID
Replies: 26
Views: 2129

Re: AtomSID

I personally can't.. maybe Dave Hoglet could (give his view).
by bprosman
Sat Jul 06, 2019 11:25 am
Forum: acorn atom and system
Topic: AtomSID
Replies: 26
Views: 2129

Re: AtomSID

What would be the smallest FPGA that would just hold a "SID" ? Well maybe with some additional address decoding.
by bprosman
Mon Jun 24, 2019 1:28 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 191
Views: 6682

Re: Atom Video to HDMI Adapter

Got an e-mail from Farnell that they run out of stock for the TI version of the LM319 and then its over (220 in stock).
They recommend ON Semi.

@Dave , any experience with that brand ?
by bprosman
Mon Jun 24, 2019 9:06 am
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 191
Views: 6682

Re: Atom Video to HDMI Adapter

Let me check , but let's build PCB first. Hoping to have the parts arrived this week. They add a little on to the price but at least you can get stuff in a couple of days Well , I checked that earlier this week but a 8051 core processor was 7 Euro , versus 4 Euro directly at Farnell (VAT excluded). ...
by bprosman
Sun Jun 23, 2019 5:54 pm
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 191
Views: 6682

Re: Atom Video to HDMI Adapter

Hi Roland,

Thanks for the offer, I have as well but the Dutch Farnell doesn't seem to have it in their catalog.
I can check the UK site.
by bprosman
Sun Jun 23, 2019 11:51 am
Forum: acorn atom and system
Topic: Atom Video to HDMI Adapter
Replies: 191
Views: 6682

Re: Atom Video to HDMI Adapter

Tried to order the case but the companies I found thus far charge 15...20 GBP for shipping to NL.
Thats 3..4 times the costs of the box.
So will look for a "Continental replacement".
by bprosman
Sat Jun 22, 2019 5:42 am
Forum: hardware
Topic: ATOM Restored, Space-bar needed
Replies: 24
Views: 611

Re: ATOM Restoration, Space-bar needed!

I do have a desoldering station which already cleared 2 earlier boards, so if you need some help.
by bprosman
Fri Jun 21, 2019 4:00 pm
Forum: hardware
Topic: ATOM Restored, Space-bar needed
Replies: 24
Views: 611

Re: ATOM Restoration, Space-bar needed!

Seeing ugly single sided IC socketd :(
Definitively would remove / replace those one day.
by bprosman
Wed Jun 19, 2019 4:07 pm
Forum: acorn atom and system
Topic: Moving the Atom FDC to #BC48
Replies: 5
Views: 276

Re: Moving the Atom FDC to #BC48

This is what I read in the documentation : The reason for #BC48 in the past was that this was quite easy to decode. Nowadays we stick to those addresses because there is a modified version of the DOSROM which will access the 8271 at its new address block. A modified version of DECADOS is included wi...
by bprosman
Fri Jun 14, 2019 9:22 pm
Forum: acorn atom and system
Topic: 2AtomFPGA - successor of Yarrb
Replies: 17
Views: 468

Re: 2AtomFPGA - successor of Yarrb

100 Pin 0.5mm is still do-able by hand.
Did a few XC9572's last summer.
XC9572.jpg
But most PCB manufacturers can put the components on for you as well.
by bprosman
Wed Jun 12, 2019 7:22 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 657
Views: 54843

Re: ICE T65/Z80/6809

Sure please contact me via a private message and I’ll send you one.
by bprosman
Wed Jun 12, 2019 12:58 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 657
Views: 54843

Re: ICE T65/Z80/6809

@Tom,

I did make a small converter PCB for this :

viewtopic.php?f=41&t=12954&p=221943&hilit=ice+t#p221943
by bprosman
Wed Jun 12, 2019 12:27 pm
Forum: hardware
Topic: 6847 Tester
Replies: 4
Views: 406

Re: 6847 Tester

Would this also work for the 6845 ?
by bprosman
Sun Jun 09, 2019 9:45 am
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

Would prefer that but lacking FPGA skills, so might go for an Arduino.
by bprosman
Sun Jun 09, 2019 8:32 am
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

Nice board but for testing the Arduino Mega2560 should be sufficient.
by bprosman
Sun Jun 09, 2019 7:55 am
Forum: upcoming and recent events & exhibitions
Topic: Dutch Techsat 2019
Replies: 36
Views: 2235

Re: Dutch Techsat 2019

Unfortunately due to family circumstances I couldnt be there :( .
Looking forward to pictures (if any have been made).
by bprosman
Thu Jun 06, 2019 6:54 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 757
Views: 36174

Re: RGB to HDMI using a Pi Zero and a small CPLD

Glad you worked it out.
by bprosman
Thu Jun 06, 2019 12:46 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 757
Views: 36174

Re: RGB to HDMI using a Pi Zero and a small CPLD

Sue him Dave :evil: :evil:
by bprosman
Mon Jun 03, 2019 3:35 pm
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

As you indicate, the easiest option is to fit a suspect 6522 in a BBC B. If the system will not run when the suspect 6522 is put in the ‘system VIA’ socket, it’s toast. If the system runs with the suspect 6522 in use, it’s almost certainly fine. Do not completely agree with this, as I have a BBC B,...
by bprosman
Mon Jun 03, 2019 8:12 am
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

The difficulty would be working out what to do to each pin to test them and what I imagine would be fairly laborious code for each of the pins. I am also not sure how re-usable the code would be between different logic devices. For the simple I/O tricks it wouldn't be that difficult, but it gets ex...
by bprosman
Mon Jun 03, 2019 7:17 am
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

Logic chips (74xx and 40xx) is not such an issue, I can use my TL866 for that.
by bprosman
Sun Jun 02, 2019 11:10 pm
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

Re: 6522 (and maybe others) tester.

a tester that tested 6522s and 6502 would be good
And the 8255, 6845 and 6847 without being greedy :mrgreen:
by bprosman
Sun Jun 02, 2019 9:48 pm
Forum: acorn atom and system
Topic: 6522 (and maybe others) tester.
Replies: 17
Views: 436

6522 (and maybe others) tester.

Is it possible to create a 6522 tester using an FPGA (EEPizza) or CPLD ? I have a whole bunch of these, some of them are from the "C64 Speeddos days" so most probably a blown up port. Some functions can be tested by plugging it into an Atom or BBC but that is still no guarantee. I have a BBC where 2...
by bprosman
Sun Jun 02, 2019 9:30 pm
Forum: hardware
Topic: 2Mhz clock from 4Mhz crystal
Replies: 5
Views: 285

Re: 2Mhz clock from 4Mhz crystal

The MPF-1B is one of the designs that uses this.
Clock in on pin 3, Clock/2 out on pin 6.
ClockDiv.JPG
by bprosman
Sun Jun 02, 2019 9:24 am
Forum: acorn atom and system
Topic: Acorn Atom power connections on motherboard.
Replies: 45
Views: 1405

Re: Acorn Atom power connections on motherboard.

Indeed as that is part of the filter but that is the only one. Instead of "recapping" I would more suggest "resocketing".
by bprosman
Sat Jun 01, 2019 8:32 am
Forum: acorn atom and system
Topic: SAA5050
Replies: 2
Views: 213

SAA5050

Looking into older designs of Acorn video boards I was wondering if the SAA5050 is still obtainable or even "emulatable" in a smaller CPLD or FPGA?
Actually not looking for a whole "Vdu board in a chip" , still in combination with an 6845.

Kind regards, Bram
by bprosman
Fri May 31, 2019 9:29 am
Forum: acorn atom and system
Topic: Acorn Atom power connections on motherboard.
Replies: 45
Views: 1405

Re: Acorn Atom power connections on motherboard.

As they are just used for DC decoupling and not on high(er) frequencies like in a switching power supply I doubt whether this is going to make a huge difference.