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BigEd wrote: ↑

Wed Apr 14, 2021 5:31 pm

(Edit: looked at this way, it's no help to compute the number of days difference - as is clear, we don't know how to divide all those days into months)

What we need here is metric time. 100hr days, 10 day weeks, 100 week years. Simple. That way we won't run out of time so quickly!

Personally speaking, I'll take a 1 in a million chance over a 1 in 1000 (or worse) any day of the week! :) I agree. However, I understand that the relative risks are much more marginal amongst the younger population, which is why - even in the UK - the the under 30s are now being offered an alterna...

I've selected the XC6SLX9 FPGA in ICE, and I'm slowly progressing with the logic development. So far so good. No space issues to report, but still got quite a lot of coding to do. Given what's been said already, I'm not expecting to run into any issues here! In parallel, I've been looking at the har...

philb wrote: ↑

Sat Apr 10, 2021 10:26 pm

KenLowe wrote: ↑

Sat Apr 10, 2021 6:28 pm

Here's a few photos of some new 5.25" cases I've had built...

Very nice. Will the metalwork also accept a 5.25" floppy mech?

It should do. It might be missing a couple of screw holes on the bottom plate, but those should be easily drilled out.

Rasp wrote: ↑

Sat Apr 10, 2021 6:35 pm

Hi Ken,

how do I go about ordering one of these boards for my BBC B.

Thanks

I'll send you a PM soon. You won't be able to reply, but I'll give you alternative contact details...

This what you want? https://www.ebay.co.uk/itm/Acorn-Computer-Winchester-Disc-120/143996997012?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 That went for much more than I expected it to. Julian. Holy s**t! That's a stupidly ludicrous price! In the next couple of weeks I hope to ha...

How about using a serial PROM and serialise / deseralise into a parallel register inside the CPLD ? By the time you've got that shift register, another for the outbound address, plus a state machine to run them... well, we started out register-starved anyway. The other issue is you'll need to be ab...

The Mojo-V3 is a reasonable choice if you want a minimal dev board. It's open source and there are several suppliers. I have used the very similar EEPIZZA board for several of my projects, but it's been hard to get recently. https://www.ebay.co.uk/itm/XC6SLX9-Core-Board-with-UART/114663155388 (I us...

CPLD to XC6SLX9 is certainly quite a jump! Is XC6SLX4-2TQG144C not enough for what you need? Not that there's any harm in using the larger part of course, it just sounds like it'll end up only about 10% utilised. The reason I selected that part is because it's one of the parts that JLCPCB have in s...

I'm currently running an FPGA based system that includes: BBC Master, 65C02 Second Processor, VideoNuLA, Music 5000, 6502-ICE Debugger. This all fits in an XC6SLX9 (with an external SRAM for the BBC RAM/ROM). Do you have any recommendations on a development board? I was thinking about something lik...

Yes that makes sense and I can understand how the CPLD could quickly run out of cells. So, could you implement the lookup table in an external PROM so that your CPLD just provides the decode for the PROM address lines and the PROM data lines drive your pcb address bus ? I could possibly use a ROM a...

Firstly, for each of the 16 available ROM slots, there is a soft switch that allows the user to select either ROM socket, SWRAM, or emulated PALPROM module. This switching is currently done by writing data to locations in the &FE3x range, but it will eventually be done with a * command from the...

That's good to hear. So is that PiTubeDirect and Pi1MHz working together now?

I hope this is the right place to report my own offering in this area: I have cloned the BBC B+64K Acorn expansion board. I will not be selling this, but I am opening the CAD, etc. for anyone that wants to build one. It is hosted here: http://www.bygonebytes.co.uk/BBCBPlus_SRAM.html and here: http:...

There is a mention of OSWORD 66/67/68/69 in Acorn App Note 30: http://stardot.org.uk/mirrors/www.bbcdocs.com/filebase/library/appnotes/AppNote-030.pdf Dave Interesting. I've just found a document that is very similar to the the application note. However, the info relating to OSWORD67 is different, ...

It's also detailed in Part 1 of the Master Reference Manual, but it does seem to be a bit different to the info in the B+ guide:

http://www.8bs.com/othrdnld/manuals/ess ... Part-1.zip

That's good news on the Pi1MHz front. ADFS / Pi1Mz should be compatible with the the Tube / PI Co pro. However, it sounds like you're just having a problem getting the Pi4 to work with PiTubeDirect. Can you check that you're using the latest PiTubeDirect software? Can you also clarify what you mean ...

I built up and have tested a further 2 boards today, so if anyone's interested in one of these, just reply here, or drop me a PM.

Yes, that should work. Fingers crossed .

Using raspberry pi 4 model b 4gb ram I don't think Pi 1MHz supports the Pi 4. From the README: PiZero and PiZeroW are treated as the same. Pi3B+ is also supported via a cable as it won't fit under the computer. Pi3A+ should also work but hasn't been tested. I would have put money on the fact that i...

Can you please check that the SD Card is formatted FAT32? Not ExFAT.

Thanks.

I got my AstraZeneca jab yesterday at about 2pm. By 10pm, I could sense something wasn't quite right. I could feel the start of some aches and pains. I then had a very restless nights sleep. I felt quite ill - cycling between cold chills and hot sweats for a few hours. Thumping headache throughout. ...

I like the Lattice (was SiliconBlue) iCE40 family for this kind of "slightly more than a CPLD" application. They are cheap and easy to use, are quite well equipped with block RAM, and you don't have to pay for the toolchain. Also the tools run on Linux which is a bonus for me. Downsides: ...

Seeing that you'll need yet more registers for each of the PALPROMs (i.e. the 3 or 4 bits that were in the PALPROM's PAL) as well as the configuration ones, I think you might exceed what you can get in a CPLD. The other issues with the CPLD architecture are that the logic is not entirely arbitrary....

Coming to this from a position of complete ignorance - you want to switch in 1 of 64 banks from a 1MB ? So you want to control the top 6 address bits with a CPLD? How are you planning on selecting which bank to use ? That's correct. The CPLD will control the upper address bits of the RAM. Within th...

Hi Ken, I can't seem to reply to PMs - was sure I could before! Just to confirm, address is same as for the level shifters. Again - Many thanks for building one up! You need to have 25 posts before you can reply to PMs. I did leave my email address in one of my PMs to you, so if you do need to get ...

Does this sound at all achievable using the XILINX CPLDs, or am I expecting way too much from them? I seem to run out of space quite quickly, even on the largest CPLD. Any pointers gratefully accepted! There are two data points that might help: - The device that is currently being used and it's uti...

Hi folks, If possible, I'd like to get a little bit of time in the morning with the experts to discuss some of the CPLD space constraint challenges I'm facing with my project, and to get their thoughts on where I should go from here. Happy to take this to a week day evening meet if that would be mor...

tricky wrote: ↑

Thu Apr 01, 2021 5:20 pm

For anyone else "MMFS2"

Actually, I think the version that doesn't use the container .mmb file is now being referred to as MMFSv2 to avoid confusion with the version of MMFS that is built with a different user port address, and is also called MMFS2.

Folks, I want to further develop my IntegraB board to allow the end user to add a number of PALPROM based ROM images to the board, and I'm looking for a bit of guidance. The PALPROM concept has been tested on my development board, and is working well. However, the switching zones associated with the...