Search found 148 matches

by Budgie
Sun Oct 11, 2020 4:07 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

No problem

Cheers
by Budgie
Sat Oct 10, 2020 3:31 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

hoglet wrote:
Thu Jun 25, 2020 8:50 pm

The PCB you sent arrived this morning; thanks. Can I ask what technique you used to build the board? I've not soldered a PLCC with a large central pad before.

Dave
Hi Dave

Did you ever get round to building this board ? Just curious to see if it worked okay.
by Budgie
Sat Jul 04, 2020 4:23 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

MMFS is working at 4Mhz from the AP5 so now easy to load games at full speed. Everything now looks to be working as it should and is reliable where you can expect it to be so. This now looks like a fully viable solution as a replacement ULA with some benefits to boot. Loads of thanks to Dave for all...
by Budgie
Fri Jul 03, 2020 9:59 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Okay latest update (All testing against V1.02 of Electron ULA Board) Note the V1.02 board version is missing the Keyboard pull ups but Github has version 1.03 with the pull ups included if anybody wishes to make one. This makes the keyboard work at higher CPU clock speeds although Dave has a fix for...
by Budgie
Wed Jul 01, 2020 12:44 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

The latest changes which apply the IO and ROM slowdown look to be working well based on the basic testing I have done so far. I'm currently trying to get the UFM in the MAX10 working for the ROM at 4Mhz but its not working for some reason, so 4Mhz still needs testing. Not updated Github yet
by Budgie
Sat Jun 27, 2020 8:04 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Great stuff ! I should be able to test this tomorrow. I will let you know. Thanks !
by Budgie
Fri Jun 26, 2020 6:10 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

I looked at the 4Mhz speed issue further and found that the design does not give out any clock signal at this speed. Looks to be down to this part of the code. I increased the clock from 16 to 32Mhz for this block and it works but not sure about the duty cycle being okay. The ICE can now read the RA...
by Budgie
Thu Jun 25, 2020 10:32 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

I'm in line with Phil's thoughts. I would like to keep the hardware changes from now to only be "fixes" but it would make sense I guess to make full use of the FPGA's capabilities if Dave's happy to continue his major contributions where this may be required
by Budgie
Thu Jun 25, 2020 10:06 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

What are people's thoughts on where we want to go with the "Basic" board ? My original intention was to just have it replace the orginal ULA really but I'm happy to get it working "fully" if other people think this is appropriate or maybe that's what we leave Phil's board for ? 1...
by Budgie
Thu Jun 25, 2020 10:00 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

I've had a few "4MHz 6502s" fail at 4MHz - So if you'd like to try a few more I can send some over - ? Dave H :D Interestingly only 2 of the 4 UM6502's I have work, even with the original ULA. I then tried a WD65c02. Left pin 1 disconnected and tied BE high, this booted but appears to hav...
by Budgie
Thu Jun 25, 2020 8:32 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Latest testing results.. 1. Keyboard With no modifications the V1.02 board and latest RTL works at 1Mhz no contention and 2Mhz Contention If I add 10K or 4.7K or 2.2K to 5V resistors to the keyboard inputs to the buffers then 2 Mhz no contention also works 4Mhz no contention cannot be tested yet see...
by Budgie
Wed Jun 24, 2020 2:12 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

If my Electron's cassette I/O wasn't so unreliable with the devices I have, I might try to map out its response in various circumstances. I suppose that would be another test for Budgie: trying to load some of the games that have non-standard tape loaders. Let me know of some game examples and I'll...
by Budgie
Tue Jun 23, 2020 9:37 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Genius ! Steady as a rock now when in default mode 01 (CTRL/CAPS LK 6) standard Electron ! pic10.jpg . . Also the keyboard is now working for CTRL/CAPS LK 5 and 6. Firetrack also working well Returning to something you said earlier Andy: On switch on it is as per above. If I then do CTRL/CAPS LK 5, ...
by Budgie
Tue Jun 23, 2020 11:58 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Sorry I apologise for the bombardment here. I just thought I would "spit-out" what I'm finding as such. I'm not expecting anything to be fixed, just passing on. The kicad and VHDL is now on github. This is mostly as per your code except I stripped out MMFS and VGA (for now) but kept mode 7...
by Budgie
Tue Jun 23, 2020 10:43 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

The keyboard issue is the same one encountered by Myelin. See this post for more details on what's actually going on. This only affects a real Electron keyboard (with slow/weak pullups). These modes work fine in ElectronFPGA with the PS/2 keyboard. The bottom line is that the real ULA slows down to...
by Budgie
Mon Jun 22, 2020 9:38 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

I have tried the last Github commit and can confirm that this makes the picture look correct. It does however seem to mess up the keyboard. I get the same issue with the keys on the previous version when I increase the CPU speed with CTRL/CAPS LK and 6 or 7, 8 just locks the machine. Symptoms are ke...
by Budgie
Sun Jun 21, 2020 4:20 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

=D>
by Budgie
Sun Jun 21, 2020 2:31 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Good luck. Your ICE is so useful for this work. I used it to get the first ULA board working.
by Budgie
Sat Jun 20, 2020 9:36 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Excellent !!
by Budgie
Fri Jun 19, 2020 5:06 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

This is really more one for Dave (Hoglet). My understanding is the timing is effectively "emulated" as the memory is actually block RAM in the FPGA which does not actually create any contention so Dave creates it as such.

It may be too much effort to create exact timings though. Not sure !
by Budgie
Fri Jun 19, 2020 2:46 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

When I do *LOAD PICT2 for example I get a static picture doesn't look as good as the ones shown in the forum. If i then run *SHOW it flickers quite noticably and the colours don't look right. Maybe doesn't work on an Electron ? I've not fully read the distructions, does it only work on a CRT ? Looks...
by Budgie
Fri Jun 19, 2020 11:35 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Looks amazing! :D I would be interested to test any programs which really challenge the hardware. Maybe try this palette demo , which runs using a combination of a ROM and a disk image. I imagine you can just load the ROM into sideways RAM. I tried this. Loaded the ROM into slot 4 (also tried 7) an...
by Budgie
Fri Jun 19, 2020 11:17 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Thanks Mark. I guess this makes sense when you see it at the component level. I also find it weird how an input can both sink and source current !
by Budgie
Thu Jun 18, 2020 10:09 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Wonder if non Nula doom would play on pi 2nd processor? Should tax the tube bus timings (would 2nd processor version of elite maybe run). And any mode 7 adventure games that would have been bbc only (maybe see if map quiz will run). Doom ! I didn't even realise this existed. I found the thread, awe...
by Budgie
Thu Jun 18, 2020 8:32 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

The V1.02 boards arrived and I have built one. All appears to be working as it should ! Pic1.jpg Pic2.jpg Screen shot showing it working on both RGB and composite monitors with my granddaughter playing Chuckie Egg :) Pic6.jpg Tube Pic3.jpg Other stuff working - Pegasus disk drive / AP6 Pic5.jpg Even...
by Budgie
Wed Jun 10, 2020 11:45 am
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

When using the oscillator on the Electrol board, is this used only as an input to a MAX10 PLL, or is it used directly as a logic clock? It's an input to the PLL on the MAX 10. Hopefully the circuit board 16Mhz clock will be reliable on all models of the Electron ! The input buffer supports hysteres...
by Budgie
Tue Jun 09, 2020 9:33 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

I've made some changes to the board (Now V1.02) to fix the IRQ and RESET issue. They needed to be open collector and properly implemented with buffers. I managed to get the 74HCT125 on there in the end to hopefully allow for an internal 6502 (again went with Myelin's recommendation). I've also added...
by Budgie
Fri Jun 05, 2020 11:12 am
Forum: past all-day virtual ABugs
Topic: All-day 'Virtual' Acorn session #4, Saturday 6th June 2020, 9am - 10pm - NOW FULL
Replies: 119
Views: 8648

Re: All-day 'Virtual' Acorn session #4, Saturday 6th June 2020, 9am - 10pm

I would like to attend if possible just to see what goes on throughout the day and there looks to be some interesting content. Again never been on before so would just need to know how to "get connected". Zoom I believe ?

Many thanks Andy
by Budgie
Wed Jun 03, 2020 3:20 pm
Forum: 8-bit acorn hardware
Topic: Electron ULA Basic Board
Replies: 89
Views: 6092

Re: Electron ULA Basic Board

Yes, I believe that’s the case; you should be fine with just nIRQ and RESET. RnW is there on my board so I can drive it when using an internal CPU, and the caps led output is just there because it was the last output buffer pin available :) This board is looking really nice! I’d definitely like to ...

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