Search found 1009 matches

by fordp
Sun Apr 21, 2019 5:59 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Let's see what turns up. I am looking forward to this.
by fordp
Wed Apr 17, 2019 5:07 pm
Forum: hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 65
Views: 2469

Re: Raspberry Pi to 1MHz bus interface

My kit arrived today, many thanks. Looks like all the diodes point the same way? Is there a GitHub project?
by fordp
Thu Apr 11, 2019 6:47 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

My only comment is that I am surprised the 3.3V plane does not run under the entirety of the FPGA board as there is nothing running at 5 V there. The highest speed and most critical part is the fast SRAM right under that board.
by fordp
Wed Apr 10, 2019 6:54 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I may be imagining things but was there a design for a perspex (acrylic) laser cut case for an atom in the past?
by fordp
Tue Apr 09, 2019 10:02 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I am not and expert but would like to look at the KiCad design. I hope to build on this project with one of my own I have been planning. I saw in the past that Hoglet ( Dave) made a homebrew Atom keyboard is that design available. It would be great to have an Atom design with all modern easy to get ...
by fordp
Tue Apr 09, 2019 6:49 pm
Forum: hardware
Topic: US specification BBC Micro
Replies: 3
Views: 246

Re: US specification BBC Micro

I have one of those US keyboards that has never left England. It was probably a prototype!
by fordp
Tue Apr 09, 2019 12:39 pm
Forum: programming
Topic: Which C Compiler?
Replies: 9
Views: 822

Re: Which C Compiler?

Does anybody have interesting open source projects for a 6502 based Acorn computer in C out there I would love to have a look?
by fordp
Thu Apr 04, 2019 12:03 pm
Forum: hardware
Topic: Phoebe PCB
Replies: 34
Views: 2666

Re: Phoebe PCB

The main ICs look a long way from the battery and if the ICs work then it is fixable. There are some very skilful people at repairing PCBs. Is there any point in having it running however is another issue!
by fordp
Sun Mar 17, 2019 7:42 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released
Replies: 522
Views: 22943

Re: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released

The reason I ask is that I would like a build for the Native Raspberry Pi CoPro with hardware VFP floating point. Are the floats in Brandy compatible with the VFP on the Pi? I have to say, I don't know - I don't really know anything about the Pi's VFP instructions (last ARM programming I did was YE...
by fordp
Sun Mar 17, 2019 12:45 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released
Replies: 522
Views: 22943

Re: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released

The reason I ask is that I would like a build for the Native Raspberry Pi CoPro with hardware VFP floating point. Are the floats in Brandy compatible with the VFP on the Pi?
by fordp
Sat Mar 16, 2019 6:15 pm
Forum: software & utilities for the pc, mac or unix
Topic: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released
Replies: 522
Views: 22943

Re: Matrix Brandy BASIC V for Linux with SDL: V1.21.19 released

Has anybody tried building Matrix Brandy for RiscOS on a Pi?
by fordp
Thu Mar 14, 2019 6:01 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I will have a look for a PI connector. Maybe on the keyboard side just like where PL8 used to be. When mounted at the level shifters it might clash with an internal eurocard board in PL6/7. I agree that there should be a Pi Zero connector :) Would it not make more sense on the other side of the boa...
by fordp
Wed Mar 13, 2019 6:02 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I have a simple request which yet again you can of course ignore without offending me. I hear you are using the extra connector. Would it be possible to put the Atom Keyboard on that connector. The thinking behind this is that the keyboard is optional so by not fitting a board to board connector for...
by fordp
Tue Mar 12, 2019 10:23 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I mainly do software these days so pay me little head but is the 7445 a 5V device in which case will it not feed 5 V back in to the keyboard inputs?

Maybe they are open collector in which case may well be OK.
by fordp
Tue Mar 12, 2019 9:34 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Like Dave said earlier this is an Atom first and foremost. I still think a pretty good master or Electron can be made on the same board and the challenge of that interests me. If we have a Pi interface then an onboard 6502 CoPro will not be required which should mean the memories will not need to be...
by fordp
Tue Mar 12, 2019 5:32 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

roland wrote:
Tue Mar 12, 2019 2:03 pm
hoglet wrote:
Tue Mar 12, 2019 12:51 pm
Do you mean SOJ-36 for the SRAM?
Yes, that's the one I mean. The PLCC are easier to find....


What are SOJ-36 components used for if it's so hard to find a socket for them?
They used to be used for cache RAM and Graphics RAM but cache went on chip and graphics moved to DDR and GDDR.
by fordp
Tue Mar 12, 2019 12:55 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

SOJ sockets are like hens teeth but they did manage to source some for the SpectrumNext project.
by fordp
Tue Mar 12, 2019 12:46 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Did you mean PLCC32??? For PLCC I guess China is the answer: e.g. https://www.aliexpress.com/item/Complete-PLCC-general-adapter-set-includes-PLCC20-28-32-44-to-DIP20-24-28-32-40/32809824378.html?spm=2114.search0104.3.2.79af2a1c9uRhWj&ws_ab_test=searchweb0_0,searchweb201602_8_10065_10068_10130_10547_...
by fordp
Mon Mar 11, 2019 11:27 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Just to be clear emulating a BBC Master plus 65c02 CoPro would take 128K Master RAM (Equivalent to the 4464 x 4) plus 256K Sideways Space, plus the OS ROMS plus 64K for the Copro. I think that will fit in 512K Bytes, Phew!
by fordp
Mon Mar 11, 2019 10:56 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

There is something to be said for not having parallel Flash as it can be much slower than RAM. A common option is to copy the ROM contents from a serial FLASH memory. It may be possible to store the ROMs on the flash chip on the FPGA board?
by fordp
Sun Mar 10, 2019 11:31 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Do not be too hasty. The RAM is more important than the flash. This has to be an Atom first with anything else being a lucky bonus I think. I guess if it does not compromise the design 5V memories could be OK. If the address lines are always from the FPGA they may not need level shifting.
by fordp
Sun Mar 10, 2019 7:13 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Simon, do you suggest that you actually want such a board as you are already searching for components :lol: But what on earth should we store in 1MB memory in an Atom? 640 kB ought to be enough :mrgreen: You are not thinking laterally. I am good at that. That memory may be a bit of overkill for an ...
by fordp
Sun Mar 10, 2019 11:52 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

I would plus 1 on the previous post and have 2 bits per colour. I think 2 extra pins would be well used on upping the RAM and Flash to 512K Bytes each Nothing to do with me having SST39SF040-70-4C-PHE and AS6C4008-55PCN in stock ;)
by fordp
Sun Mar 10, 2019 8:23 am
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

Memories will run at 3.3V. Within a few days I will post the first draft of the schematic diagram. Brilliant. Just one more idea to save lots of pins at the expense of some logic gates but I would have thought the keyboard could be multiplexed on to the address and data bus with just maybe one pin ...
by fordp
Sat Mar 09, 2019 9:57 pm
Forum: acorn atom and system
Topic: Atom 2k18 ?
Replies: 204
Views: 6242

Re: Atom 2k18 ?

This looks interesting. I am not totally sure why you would run the memories at 5V however I would have thought running those at 3.3V would have saved a lot of complexity.
by fordp
Fri Mar 08, 2019 7:02 pm
Forum: hardware
Topic: Music 5000 FPGA
Replies: 70
Views: 11906

Re: Music 5000 FPGA

I wonder do you think somehow this could be hooked up to something other than a BBC micro......say a raspberry pi or something? Not directly, as the 1MHz bus is 5V TTL. You could design a similar adapter board for the Pi, but replace the level shifters and 1MHz Bus connector with Pi GPIO connector....
by fordp
Fri Mar 08, 2019 3:33 pm
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 63
Views: 1750

Re: Beeb 1MHz Bus FPGA Adaptor

The FPGA board on ebay looks like the JTAG connector will clash with your PCB Dave. Maybe it will have to be taken out and soldered on the other side of the PCB? Are you going from the picture on eBay? That's not actually accurate. The board that is now shipped is slightly different. Look at the pi...
by fordp
Fri Mar 08, 2019 9:25 am
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 63
Views: 1750

Re: Beeb 1MHz Bus FPGA Adaptor

The FPGA board on ebay looks like the JTAG connector will clash with your PCB Dave. Maybe it will have to be taken out and soldered on the other side of the PCB?
by fordp
Thu Mar 07, 2019 6:04 pm
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 63
Views: 1750

Re: Beeb 1MHz Bus FPGA Adaptor

hoglet wrote:
Thu Mar 07, 2019 11:46 am
fordp wrote:
Thu Mar 07, 2019 10:04 am
I do not seems to be able to edit/open the WIki.
Try again now Ford.
Thanks Dave,
It works!