Search found 420 matches

by myelin
Mon Mar 12, 2018 5:34 pm
Forum: hardware
Topic: RGB keyboard LEDs?
Replies: 26
Views: 1178

Re: RGB keyboard LEDs?

I try to avoid posting too many "That's really cool!" posts myself to keep the noise levels down, but I can see how it might be discouraging. I completely agree with cmorley on this - I read all sorts of threads on here and think they're cool, even if I wouldn't really want to own one myself (for h...
by myelin
Fri Mar 09, 2018 12:05 am
Forum: software
Topic: POLL: Kickstarter project - Hero: The Realm
Replies: 47
Views: 6275

Re: POLL: Kickstarter project - Hero: The Realm

This forum is generally a super friendly place, but can get a little negative when someone joins and starts marketing a project straight away. More of a small town than big city atmosphere, perhaps ;) Good luck with the project! I don't have any Acorn ARM hardware (any more... used to have an A4000 ...
by myelin
Tue Mar 06, 2018 1:38 am
Forum: hardware
Topic: Acorn's Second Processors and the Tube - what, and why
Replies: 47
Views: 3233

Re: Acorn's Second Processors and the Tube - what, and why

tbh, untill someone makes a vid of this running on a spectrum,(or spec next) I dont think anyone is gonna be convinced. Get some hardware to Hoglet, and I'm sure something will show up in short order :) I need a diagram of the spectrum/pi set up. not a bbc>>z80 setup as existed physically in the 80...
by myelin
Mon Mar 05, 2018 6:23 pm
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

Progress note: the grid spacing on Revaldinho's full size picture is *almost* perfectly regular, but just off enough that some manual calibration is required. I've thrown together a little Processing app to let me draw in grid lines. Once that's done, I'll chop the image up into individual squares a...
by myelin
Mon Mar 05, 2018 1:38 am
Forum: hardware
Topic: HostFS and microcontrollers?
Replies: 48
Views: 3136

Re: HostFS and microcontrollers?

Myelin already started and cracked the timing for the hardware flow control which helped! He mentions sync issues above which are a bit worrying - I added in an interrupt routine to help track CTS changes which might fix this. It seems fine on one large transfer... not tested much else yet. It's go...
by myelin
Sun Mar 04, 2018 8:24 am
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

That's good news... all the ones I've seen are in plastic DIP packages; I didn't realize there were ceramic versions also.
by myelin
Sun Mar 04, 2018 4:11 am
Forum: acorn atom
Topic: Crazy idea? Downgrade Electron to an Atom? Possible?
Replies: 19
Views: 929

Re: Crazy idea? Downgrade Electron to an Atom? Possible?

Back to the original premise... I’m curious how *many* ULA-less Electrons there are out in the wild. Does everyone here have one? I have two working Elks and would be curious to try making a ULA replacement, or trying out Dave H’s board, but I don’t want to touch my working ULAs; anyone got a broken...
by myelin
Sat Mar 03, 2018 9:44 pm
Forum: hardware
Topic: Mega Games Cartridge (MGC) MK II Hardware Development
Replies: 30
Views: 1488

Re: Mega Games Cartridge (MGC) MK II Hardware Development

I’ll take care of the Model C, to be wired internally into the Elk!
by myelin
Sat Mar 03, 2018 6:43 pm
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

If anyone's breaking out the acid to dissolve some chips, might I suggest that the MSI gate arrays (the CF3xxx chips) in the Master 128, plus the serial and video ULA from the Model B, would be very interesting to see, and are, as far as I can tell, unphotographed so far... I've worked in image proc...
by myelin
Sat Mar 03, 2018 4:06 am
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

My copy of his book just arrived :)

The Elk ULA (12C021M) uses the same cells as the Spectrum/ZX81 ones (6Cxxx). My intention is to extract the wiring pattern from revaldinho’s photo, and use Hoglet’s code to turn it into a netlist that can be converted into authoritative “source code” for the chip.
by myelin
Fri Mar 02, 2018 10:37 pm
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

:D :D I could definitely do something useful if there's a full size version of similar quality to that close up!
by myelin
Fri Mar 02, 2018 10:34 pm
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

I wonder if the off-grid routing was a manual exception to get something tricky to fit in... because almost everything else zig zags all over the place when it needs to go on a diagonal. I feel that the transcription process here will be mostly automatic with a ton of manual cleanup afterwards. Fing...
by myelin
Fri Mar 02, 2018 10:04 pm
Forum: hardware
Topic: Electron ULA Schematics
Replies: 45
Views: 3189

Re: Electron ULA Schematics

I just came across this picture on Flickr , a die shot of the 12C012M ULA! If you click on it and view the highest resolution picture, it looks like there's *just* enough resolution to view the entire metallization pattern, which should hopefully allow us to extract the exact circuit, using Hoglet's...
by myelin
Thu Mar 01, 2018 8:05 pm
Forum: introduce yourself
Topic: Hello from California, possibly Exile's biggest fan!
Replies: 25
Views: 1206

Re: Hello from California, possibly Exile's biggest fan!

Welcome! I’m the SF-dwelling Electron hacker Thomas Harte mentioned a few posts back. (Thomas, I got your email, unfortunately right after I’d landed back in SF after a week in NYC!)
by myelin
Mon Feb 26, 2018 12:39 am
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1489

Re: Pi Zero Super Interface

Kicking myself for not bidding more on the one Master Compact I’ve seen on eBay now; this sounds like fun :)
by myelin
Thu Feb 22, 2018 7:06 pm
Forum: hardware
Topic: HostFS and microcontrollers?
Replies: 48
Views: 3136

Re: HostFS and microcontrollers?

I'm interested in this too, especially since I saw my Arduino MKR1000 mounts nicely onto a BBC micro ashtray (assuming the cover got pushed in during the 80s... like happened on mine). I was wondering if you could have MicroPython running on the MCU host, or given it has WiFi onboard, serving some ...
by myelin
Thu Feb 22, 2018 2:26 am
Forum: general
Topic: led light range
Replies: 3
Views: 367

Re: led light range

Probably not on topic for the 8-bit hardware board... maybe move this to miscellaneous < off-topic?
by myelin
Wed Feb 21, 2018 9:32 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1489

Re: Pi Zero Super Interface

jgharston wrote:there's no "SHEILA" signal on the edge connector.
Doesn't the Master Compact edge connector bring out the full address bus, like the edge connector on the Electron? If I haven't misread the schematic, it looks like it should be easy enough to generate the "SHEILA" signal from A8-15.
by myelin
Wed Feb 21, 2018 7:55 pm
Forum: hardware
Topic: Pi Zero Super Interface
Replies: 23
Views: 1489

Re: Pi Zero Super Interface

Does a Pi in a cartridge interface similarly make sense - or maybe that's already been considered? There's my two Pi-on-a-cartridge projects -- http://myelin.nz/acorn/elktube and http://myelin.nz/acorn/fx2tube -- which should be a good place to start for anyone intending on prototyping something al...
by myelin
Wed Feb 21, 2018 6:37 pm
Forum: hardware
Topic: Myelin's in-system updateable MegaROM for the BBC Master 128
Replies: 31
Views: 1671

Re: Myelin's in-system updateable MegaROM for the BBC Master 128

Good news! Last night I got it all working. It looks like there must have been some kind of grounding issue once I plugged the board into an actual Master 128; I solved it with some tweaks to the Verilog that made it a bit more noise tolerant. Now I can read and write the flash while the machine is ...
by myelin
Fri Feb 16, 2018 9:59 am
Forum: hardware
Topic: Myelin's in-system updateable MegaROM for the BBC Master 128
Replies: 31
Views: 1671

Re: Myelin's in-system updateable MegaROM for the BBC Master 128

So... I just got a chance to try this out in some real hardware, and the results are pretty puzzling. The in-circuit programming part of the system seems to not be working at all; when I take over the address bus on the flash chip (by getting my CPLD to stop buffering the address signal from IC20, a...
by myelin
Wed Feb 14, 2018 9:18 pm
Forum: hardware
Topic: Myelin's in-system updateable MegaROM for the BBC Master 128
Replies: 31
Views: 1671

Re: Myelin's in-system updateable MegaROM for the BBC Master 128

DualOS and GoMMC just don't quite fit together. I was wondering if there was some way of shaving the side of an IC header down a bit. Hm, so the GoMMC really does stick out a bit too far. Interesting to see the placement of the cartridge slots too... I only have a Master 128 motherboard, not a full...
by myelin
Wed Feb 14, 2018 7:57 pm
Forum: hardware
Topic: Myelin's in-system updateable MegaROM for the BBC Master 128
Replies: 31
Views: 1671

Re: Myelin's in-system updateable MegaROM for the BBC Master 128

Which way around does it plug in? It looks like it will either clash with my network card or clash with my GoMMC. It plugs in to IC24 and extends out over IC37 (away from the Econet module). I've confirmed that it doesn't clash with a standard Econet module, but I haven't checked if it clashes with...
by myelin
Wed Feb 14, 2018 6:53 pm
Forum: hardware
Topic: Myelin's in-system updateable MegaROM for the BBC Master 128
Replies: 31
Views: 1671

Re: Myelin's in-system updateable MegaROM for the BBC Master 128

An update on this one... I forgot about it for a while, but over the last couple of weeks have been working on the Verilog and C code to bring it to life. I haven't tested it in an actual machine yet, but am able to program and read the flash over the SPI connection now, which is the hard part. I'll...
by myelin
Mon Feb 12, 2018 9:49 pm
Forum: hardware
Topic: Mega Games Cartridge (MGC) MK II Hardware Development
Replies: 30
Views: 1488

Re: Mega Games Cartridge (MGC) MK II Development

Thanks Dave. It does seem a shame to lose the option of a second SD Card interface, though only on the grounds that "more seems like better". :-) I can't actually think why you'd want two, but maybe there is a specific idea about this floating around. It was a request from Phil (Myelin) It's someth...
by myelin
Thu Feb 01, 2018 6:04 pm
Forum: hardware
Topic: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket
Replies: 34
Views: 1881

Re: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket

The FX2 board was what I thought you were sending me originally! I don't think I'd made those back when I sent you the first batch of PCBs (the one that got lost in the mail), and then I forgot to include one in the second lot :) Latest update on the Max 10 project: I got sideways ram (using FPGA b...
by myelin
Thu Feb 01, 2018 5:38 am
Forum: hardware
Topic: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket
Replies: 34
Views: 1881

Re: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket

I thought I'd run into the limit without decoupling, so I added a bunch of capacitors, and then found the bug in my VHDL that was causing all my issues :P I now have a 16k RAM block working, and have pushed my latest project files up here (in the 10m04_cpu_socket folder) -- https://github.com/google...
by myelin
Thu Feb 01, 2018 12:38 am
Forum: hardware
Topic: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket
Replies: 34
Views: 1881

Re: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket

I'm running it with a real 6502. I'd like to try the soft-core approach once I've verified that everything is stable enough... baby steps. I didn't get around to pushing anything to github last night, but maybe tonight, now that I actually have something that doesn't just constantly crash :) I'm puz...
by myelin
Wed Jan 31, 2018 10:44 pm
Forum: hardware
Topic: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket
Replies: 34
Views: 1881

Re: Electron 6502 desolder / socket pics + Max 10 FPGA in CPU socket

It looks like the problems were entirely due to my shoddy assembly on the first board. I soldered up another one, very carefully applying solder paste using the stencil and then reflowing the new chip on the hot plate I've used for a bunch of reflow projects in the past (the one in this video ), and...
by myelin
Wed Jan 31, 2018 6:09 pm
Forum: hardware
Topic: Myelin's FX2 Tube/Cartridge Adapter - Development and Support
Replies: 46
Views: 2218

Re: Myelin's FX2 Tube/Cartridge Adapter - Development and Support

It's a pity that SYNC doesn't go through the CPLD, because it would be really easy to just latch it on the rising edge of the clock! Maybe I should have just started off with a 64-pin xc9572xl after all :) I don't suppose it's possible to configure the FX2 to sample on both edges of the clock, is it?