Search found 267 matches

by Ramtop
Mon Sep 14, 2020 8:46 pm
Forum: general
Topic: ARM sold to Nvidia (by Softbank)
Replies: 6
Views: 638

Re: ARM sold to Nvidia (by Softbank)

I don't see it happening, to be honest. Even discounting the very high likelihood of the UK government blocking the deal, or at least forcing onerous conditions on it, the Chinese regulators will not want to see such a critical IP provider under the control of what it sees as a hostile power. I'm st...
by Ramtop
Fri Sep 04, 2020 6:13 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

Received a WDC65C02-14 today but despite disconnecting pin 1 and pulling BE high it didn't work when plugged into the turbo board, but worked fine directly in the Elk's CPU socket. Cue much head scratching. And then I remembered... a WDC65C02 at 5v won't accept 3.3v as a logic high, and I'm driving ...
by Ramtop
Wed Sep 02, 2020 4:21 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

PCBs have been ordered, when they arrive and I can validate that I haven't horribly messed something up I will make the PCB and HDL files available and build a few boards for those who have expressed an interest. I've re-worked the design to use a CPLD with 0.8mm pitch pins rather than the previous ...
by Ramtop
Sun Aug 30, 2020 3:41 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

A little more progress to report. After much pulling of hair and bashing of desk and bodging of wires, the turbo card now runs at 4MHz using an R65C02P4. The implementation is very 'sub-optimal' at the moment. Only the lower 12K area is 4MHz and there's a significant performance penalty going from a...
by Ramtop
Sat Aug 29, 2020 8:02 am
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

I'm going to have to disappoint on both of those, I'm afraid - at least with the current design. :( To do register based speed control the CPLD would need access to enough of the address bus to do useful decoding, and at present it only has A12-A15. For the same reason sideways RAM isn't possible as...
by Ramtop
Fri Aug 28, 2020 2:29 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

I've put up a short video showing the board in action: https://www.youtube.com/watch?v=LTD66cByMWM

(sorry for the naff quality, video is not my thing)
by Ramtop
Thu Aug 27, 2020 9:25 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

I've finished the fixes to the board, which amounted to almost a redesign. The CPU is moved back a bit for clearance and I've swapped the CPLD for a smaller, cheaper and easier to solder part. I'll order the PCBs at the weekend, they usually take about 2 weeks to arrive from China. Found time to bod...
by Ramtop
Sat Aug 22, 2020 9:52 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

Thanks, guys :D Dave, your points about sockets are well made. I had a single low-profile socket in my parts bin and planned to use it on the motherboard, but turns out the pins I'm using on the bottom of the turbo card are square in shape and won't fit into a turned pin socket. Need to get some nic...
by Ramtop
Fri Aug 21, 2020 10:34 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Re: Elk turbo board

I'll do another revision, it's fairly necessary since I really like the Elk with some extra speed and will end up fitting all of mine with turbo cards, but it's handy being actually able to close the case properly :D Toying with the concept of doing two separate versions; a bug fixed version of the ...
by Ramtop
Fri Aug 21, 2020 6:41 pm
Forum: 8-bit acorn hardware
Topic: Elk turbo board
Replies: 35
Views: 1899

Elk turbo board

Hi all, About 18 months ago I got the idea of trying my hand at a minimalist turbo card for the Electron. I finished the PCB layout, wrote most of the Verilog for the CPLD, and then became distracted by other things without ever building one to see if it worked. A few weeks back I found the old file...
by Ramtop
Sat Aug 15, 2020 10:42 pm
Forum: off-topic
Topic: PC Memory Timing Strangeness
Replies: 11
Views: 755

Re: PC Memory Timing Strangeness

That's interesting. It does seem to be do quite a comprehensive set of tests and can any set ever be exhaustive? The problem with Memtest is its generic nature as it's written to run on such a wide range of hardware. A really punishing memory test would need to be aware of the specific CPU and enti...
by Ramtop
Mon Aug 03, 2020 1:33 pm
Forum: 8-bit acorn software: classic games
Topic: Electron enhanced versions?
Replies: 13
Views: 1317

Re: Electron enhanced versions?

Was also, considering one of these... https://www.ebay.co.uk/itm/143445748901 ...but if the extra RAM isn't used by anything I'm not sure whether to or not. Cheers! The ElkSD-Plus1 needs a RAM chip on it to provide workspace for the SD card software, and since 32K chips are no more expensive than 1...
by Ramtop
Thu Jul 23, 2020 3:00 pm
Forum: general
Topic: SD Card on Fire
Replies: 31
Views: 1959

Re: SD Card on Fire

Ouch, lucky escape indeed!

SD cards have little capacitors in them which can sometimes fail as a dead short, and if the host device doesn't have current limiting on the power rail then the cap basically becomes a small heating element.
by Ramtop
Mon Jul 06, 2020 3:40 pm
Forum: off-topic
Topic: Rapid not selling 60/40 to general punters anymore?
Replies: 24
Views: 1926

Re: Rapid not selling 60/40 to general punters anymore?

If electronic and electrical devices lasted a lot longer, and the tax rules were changed to encourage economic repairs, with manufacturers not producing a new model every month, the amount of electronic and electrical devices in landfill or being exported as waste for reprocessing would drop drasti...
by Ramtop
Sun Jul 05, 2020 7:37 pm
Forum: off-topic
Topic: Rapid not selling 60/40 to general punters anymore?
Replies: 24
Views: 1926

Re: Rapid not selling 60/40 to general punters anymore?

I ran into this recently trying to order some solder from RS. Added it to the basket, confirmed the order... then they silently deleted the solder from the order and never shipped it. Happened three separate times, RS support ignored my email and eventually I had complain on twitter before they coul...
by Ramtop
Thu Jul 02, 2020 6:46 pm
Forum: general
Topic: Apple goes ARM
Replies: 66
Views: 4468

Re: Apple goes ARM

I'm not sure it's Apple losing the plot so much as they don't much care about the high-end 'creator' market any more. They haven't been able to compete there for a long time; the trashcan Mac was lacklustre even when it was new and the cheesegrater is little better. Apple putting 28 core Xeons again...
by Ramtop
Wed Jul 01, 2020 10:23 pm
Forum: general
Topic: Apple goes ARM
Replies: 66
Views: 4468

Re: Apple goes ARM

Despite that, there wasn't much software available for the other processors and eventually they gave up and went x86 only. yet Linux is available for very many processors and most of the software than runs on it is too. The difference, I suspect, is how it is delivered. The shrink-wrapped package d...
by Ramtop
Wed Jul 01, 2020 10:12 pm
Forum: for sale / freebies
Topic: Electron SD Interface & SW Ram Expansion
Replies: 58
Views: 7916

Re: Electron SD Interface & SW Ram Expansion

Oops! :D

If it's any consolation, sales on EBay are what funds development of new designs. So you've helped make sure I'll be able to keep releasing new stuff for the Electron in future.
by Ramtop
Sun Jun 28, 2020 3:41 pm
Forum: 8-bit acorn hardware
Topic: Ready-made devices to connect BBC Micro to HDMI monitor
Replies: 12
Views: 1053

Re: Ready-made devices to connect BBC Micro to HDMI monitor

I decided to stop cheaping out and bought an OSSC. That it's really not an easy device to use has been my main impression. The firmware could seriously do with some input from a user interface specialist. But I can't argue with the image quality. It looks absolutely superb, worlds ahead of the cheap...
by Ramtop
Fri Jun 26, 2020 12:56 pm
Forum: 8-bit acorn hardware
Topic: BBC B main board capacitors
Replies: 8
Views: 627

Re: BBC B main board capacitors

An A1200 without leaking caps! :shock: :D I've opened up dozens of A1200s and they all had leaking from the caps to some extent, although some of the ESCOM/AT built models seem to have only started leaking in the last few years. In the early stages leaking isn't always visually detectable until you ...
by Ramtop
Thu Jun 25, 2020 10:35 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6179

Re: Electron ULA Basic Board

In terms of soldering the FPGA. I've included the technique I used in the BOM on github. I must admit this didn't include the central pad. I applied solder paste to it and then heated with a hot air gun after drag soldering the pins. I can't be sure its soldered but that's what I did. When I was de...
by Ramtop
Tue Jun 23, 2020 1:33 pm
Forum: general
Topic: Apple goes ARM
Replies: 66
Views: 4468

Re: Apple goes ARM

My suspicion is this has more to do with Apple having gaining control over a critical part of their designs then outright performance. I'd love to see ARM being competitive in raw speed with x86, but every attempt to do that has failed so far. This move must have been in the works for several years,...
by Ramtop
Mon Jun 22, 2020 9:03 pm
Forum: general
Topic: Apple goes ARM
Replies: 66
Views: 4468

Apple goes ARM

Well, as long expected Apple are switching Macs from x86 to ARM: https://arstechnica.com/gadgets/2020/06/this-is-apples-roadmap-for-moving-the-first-macs-away-from-intel/ It's going to be interesting to see how much performance they can get from their ARM designs, and if it'll be competitive with x8...
by Ramtop
Mon Jun 22, 2020 12:19 pm
Forum: 8-bit acorn hardware
Topic: Ready-made devices to connect BBC Micro to HDMI monitor
Replies: 12
Views: 1053

Re: Ready-made devices to connect BBC Micro to HDMI monitor

I've had a GBS8220 for a while but it must be a particularly bad one as it has major noise and sparkles, even with some copper tape on the back of the PCB. I know there's a mod that can be done to replace controller with a better one, but I've never had the time to try that. Because I have so many r...
by Ramtop
Thu Jun 18, 2020 6:12 pm
Forum: 8-bit acorn software: classic games
Topic: Acornsoft Elite
Replies: 118
Views: 11231

Re: Acornsoft Elite

I suppose Frontier was a game well ahead of the hardware at the time it was released, which I could equally be said of the original Elite given how limited it was by lack of memory. On my A1200, the accelerator sped it up by around 3-4 times over a stock machine, but that still meant single figure f...
by Ramtop
Thu Jun 18, 2020 4:40 pm
Forum: 8-bit acorn hardware
Topic: Ready-made devices to connect BBC Micro to HDMI monitor
Replies: 12
Views: 1053

Re: Ready-made devices to connect BBC Micro to HDMI monitor

I have one of those £20 things off Amazon and it seems fine: the long delay to get rid of the resolution change OSD is very annoying. One issue with the cheap 20 quid converters that may not be immediately apparent is their horrendous lag. I used one of these with an Electron during development of ...
by Ramtop
Thu Jun 18, 2020 1:57 pm
Forum: general
Topic: Today I received.....
Replies: 6094
Views: 680011

Re: Today I received.....

Boydie wrote:
Thu Jun 18, 2020 12:20 pm
That's the Amiga itch scratched. :D
I know that feeling! :D This just arrived half an hour ago:
a500_1.jpg
and posing for a family portrait :
a500_2.jpg
by Ramtop
Thu Jun 18, 2020 1:09 am
Forum: 8-bit acorn software: classic games
Topic: Acornsoft Elite
Replies: 118
Views: 11231

Re: Acornsoft Elite

I agree with that, Daniel. I spent a lot of time trying to get into Frontier, but it was ultimately little fun compared to the original. As a simulation of the galaxy and a feat of coding, i’m sure it was remarkable, but that wasn’t what I was after as a teenager in the 1990s. It also didn’t help t...
by Ramtop
Mon Jun 15, 2020 11:35 pm
Forum: general
Topic: Today I received.....
Replies: 6094
Views: 680011

Re: Today I received.....

Four now, although one has a bad ULA and is mostly a parts donor.
by Ramtop
Mon Jun 15, 2020 6:08 pm
Forum: general
Topic: Today I received.....
Replies: 6094
Views: 680011

Re: Today I received.....

My mission to buy up the world's remaining supply of Electrons continues... :D

newelk.jpg

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