Search found 1752 matches

by KenLowe
Thu Apr 22, 2021 1:43 pm
Forum: wanted
Topic: BBC MMCSD Underkeyboard
Replies: 2
Views: 66

Re: BBC MMCSD Underkeyboard

I've got some of these available:

viewtopic.php?p=297054#p297054

PM me if you're interested.
by KenLowe
Mon Apr 19, 2021 12:13 am
Forum: archive requests
Topic: Topologika Adventures
Replies: 125
Views: 23979

Re: Topologika Adventures

lurkio wrote:
Sun Apr 18, 2021 3:15 pm
(Caveat: I don't really know what an FDI is or how it works!)
At a guess, I'd say it's a Formatted Disk Image:

http://www.oldskool.org/disk2fdi/files/FDISPEC.pdf
by KenLowe
Sun Apr 18, 2021 11:13 am
Forum: 8-bit acorn hardware
Topic: OS RAM module
Replies: 92
Views: 11619

Re: OS RAM module

Ken asked about the PLD code so I'm posting it here. Name adapter1; PartNo 17.006cfm ; Date 11/06/2017 ; Revision 01 ; Designer CFM ; Company n/a ; Assembly None ; Location ; Device g22v10; /* *************** INPUT PINS *********************/ PIN 1 = !clk_oe; /* clock */ PIN [11,3,9,10] = [A13..10]...
by KenLowe
Wed Apr 14, 2021 5:35 pm
Forum: introduce yourself
Topic: Calculating Accurately between two dates
Replies: 26
Views: 527

Re: Calculating Accurately between two dates

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!
by KenLowe
Mon Apr 12, 2021 10:30 pm
Forum: off-topic
Topic: Vaccination Tales
Replies: 35
Views: 1212

Re: Vaccination Tales

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...
by KenLowe
Sun Apr 11, 2021 8:56 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Sat Apr 10, 2021 11:15 pm
Forum: 8-bit acorn hardware
Topic: Finding an Acorn Winchester Hard drive
Replies: 12
Views: 454

Re: Finding an Acorn Winchester Hard drive

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.
by KenLowe
Sat Apr 10, 2021 6:39 pm
Forum: 8-bit acorn hardware
Topic: User Port Extender / SD Card Reader Interface
Replies: 53
Views: 3010

Re: User Port Extender / SD Card Reader Interface

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...
by KenLowe
Sat Apr 10, 2021 6:28 pm
Forum: 8-bit acorn hardware
Topic: Finding an Acorn Winchester Hard drive
Replies: 12
Views: 454

Re: Finding an Acorn Winchester Hard drive

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...
by KenLowe
Thu Apr 08, 2021 2:27 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Wed Apr 07, 2021 4:14 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Wed Apr 07, 2021 3:06 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Wed Apr 07, 2021 2:53 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Wed Apr 07, 2021 2:24 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Tue Apr 06, 2021 9:37 pm
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Mon Apr 05, 2021 5:31 pm
Forum: for sale / freebies
Topic: FS: Raspberry Pi to 1MHz and Tube bus interfaces
Replies: 184
Views: 13187

Re: FS: Raspberry Pi to 1MHz and Tube bus interfaces

That's good to hear. So is that PiTubeDirect and Pi1MHz working together now?
by KenLowe
Mon Apr 05, 2021 12:45 pm
Forum: 8-bit acorn hardware
Topic: The Master List for New Retro Hardware
Replies: 125
Views: 52535

Re: The Master List for New Retro Hardware

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:...
by KenLowe
Mon Apr 05, 2021 12:04 pm
Forum: programming
Topic: Where can I find OSWORD &43 (load/save into sideways RAM) documentation?
Replies: 4
Views: 207

Re: Where can I find OSWORD &43 (load/save into sideways RAM) documentation?

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, ...
by KenLowe
Mon Apr 05, 2021 10:26 am
Forum: programming
Topic: Where can I find OSWORD &43 (load/save into sideways RAM) documentation?
Replies: 4
Views: 207

Re: Where can I find OSWORD &43 (load/save into sideways RAM) documentation?

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
OSWORD 67 (&43) - Page 1
OSWORD 67 (&43) - Page 1
OSWORD 67 (&43) - Page 2
OSWORD 67 (&43) - Page 2
by KenLowe
Sun Apr 04, 2021 2:38 pm
Forum: for sale / freebies
Topic: FS: Raspberry Pi to 1MHz and Tube bus interfaces
Replies: 184
Views: 13187

Re: FS: Raspberry Pi to 1MHz and Tube bus interfaces

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 ...
by KenLowe
Sat Apr 03, 2021 8:18 pm
Forum: for sale / freebies
Topic: New Batch IntegraB ROM / RAM Expansion Board for BBC B
Replies: 35
Views: 4517

Re: New Batch IntegraB ROM / RAM Expansion Board for BBC B

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.
by KenLowe
Sat Apr 03, 2021 8:12 pm
Forum: for sale / freebies
Topic: FS: Raspberry Pi to 1MHz and Tube bus interfaces
Replies: 184
Views: 13187

Re: FS: Raspberry Pi to 1MHz and Tube bus interfaces

Yes, that should work. Fingers crossed 🤞.
by KenLowe
Sat Apr 03, 2021 6:45 pm
Forum: for sale / freebies
Topic: FS: Raspberry Pi to 1MHz and Tube bus interfaces
Replies: 184
Views: 13187

Re: FS: Raspberry Pi to 1MHz and Tube bus interfaces

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...
by KenLowe
Sat Apr 03, 2021 6:20 pm
Forum: for sale / freebies
Topic: FS: Raspberry Pi to 1MHz and Tube bus interfaces
Replies: 184
Views: 13187

Re: FS: Raspberry Pi to 1MHz and Tube bus interfaces

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

Thanks.
by KenLowe
Sat Apr 03, 2021 11:15 am
Forum: off-topic
Topic: Vaccination Tales
Replies: 35
Views: 1212

Re: Vaccination Tales

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. ...
by KenLowe
Sat Apr 03, 2021 11:04 am
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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: ...
by KenLowe
Sat Apr 03, 2021 11:02 am
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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....
by KenLowe
Sat Apr 03, 2021 10:54 am
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...
by KenLowe
Fri Apr 02, 2021 1:13 pm
Forum: for sale / freebies
Topic: New Batch IntegraB ROM / RAM Expansion Board for BBC B
Replies: 35
Views: 4517

Re: New Batch IntegraB ROM / RAM Expansion Board for BBC B

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 ...
by KenLowe
Fri Apr 02, 2021 9:11 am
Forum: 8-bit acorn hardware
Topic: Implementing PALPROM switching logic in CPLD
Replies: 27
Views: 768

Re: Implementing PALPROM switching logic in CPLD

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...

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