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by BigEd
Fri Oct 22, 2021 3:52 pm
Forum: modern implementations of classic programming languages
Topic: New: Console Mode editions of BBC BASIC
Replies: 165
Views: 12975

Re: New: Console Mode editions of BBC BASIC

Hmm, three of the four Italian resellers at
https://www.raspberrypi.com/products/raspberry-pi-pico/
seem to have stock at €4. Is that in-country shipping costs you're seeing?

(If we feel we need to move this Pico part of the conversation, I'm sure our friendly mods will do it.)
by BigEd
Fri Oct 22, 2021 8:49 am
Forum: acorn & bbc micro user group (abug) events
Topic: ABUG Dev night #28, Thursday 21st October 2021, 7pm - 10pm (BST)
Replies: 11
Views: 231

Re: ABUG Dev night #28, Thursday 21st October 2021, 7pm - 10pm (BST)

I can't believe anyone could forget about ABUG! But there'll be another one along shortly...
by BigEd
Thu Oct 21, 2021 10:02 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

Just one last bit on Pi technicalities: this piece about the memory system, and timing, and TLBs, and caches.
by BigEd
Thu Oct 21, 2021 5:23 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

I just found this note from 2016:
We've inherited a config with PVT calibration for SDRAM refresh. Let's disable that:

Code: Select all

disable_pvt = 1
(But I also note that we were worried about 100ns tails, and you have a possible problem with 100us tails - 1000x longer.)
by BigEd
Thu Oct 21, 2021 5:13 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

Before the Pi 4, the ARM had no L2 cache, I think, so an L1 miss becomes quite expensive (and quite indeterminate.)
by BigEd
Thu Oct 21, 2021 4:50 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

I'm failing to find the block diagram I want of the Pi zero's BCM2385, but there's a diagram of the Pi 4's chip in this thread . One notable thing is that while the L1 cache is in the CPU, the L2 cache belongs to the VideoCore and is on the far side of a bus - perhaps an AXI bus? I believe there is ...
by BigEd
Thu Oct 21, 2021 2:26 pm
Forum: development tools
Topic: Subtilis: A new BASIC compiler for RiscOS
Replies: 25
Views: 3422

Re: Subtilis: A new BASIC compiler for RiscOS

This might be a horrific idea, but I mention it anyway. There's a 1979 Basic interpreter for the ABC80 which supported the usual Basic types, but also offered arithmetic operations on strings - and therefore could handle very large numbers or high precisions, at a cost. See here : ...we have ADD$, M...
by BigEd
Thu Oct 21, 2021 2:19 pm
Forum: modern implementations of classic programming languages
Topic: New: Console Mode editions of BBC BASIC
Replies: 165
Views: 12975

Re: New: Console Mode editions of BBC BASIC

I haven't yet, but I intend to.
by BigEd
Thu Oct 21, 2021 2:16 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

I think our feelings on our experience with PiTubeDirect was that the long tail of latency was to do with shared resources on the chip as a whole, not things the software could control - and that's bare metal, where the software was ours. If so, it's not Linux, it's the Pi. It could be a mix of bot...
by BigEd
Thu Oct 21, 2021 12:38 pm
Forum: programming
Topic: Mini-challenge: Rotating 8-byte character definitions
Replies: 28
Views: 428

Re: Mini-challenge: Rotating 8-byte character definitions

(very naive question: why does this need a Master?)
by BigEd
Thu Oct 21, 2021 12:34 pm
Forum: modern implementations of classic programming languages
Topic: New: Console Mode editions of BBC BASIC
Replies: 165
Views: 12975

Re: New: Console Mode editions of BBC BASIC

Great to see the Pico edition in there!
by BigEd
Thu Oct 21, 2021 12:33 pm
Forum: modern implementations of classic programming languages
Topic: Matrix Brandy BASIC VI for console and SDL1.2: V1.22.11 released
Replies: 1373
Views: 144770

Re: Matrix Brandy BASIC VI for console and SDL1.2: V1.22.11 released

Richard Russell wrote:
Wed Oct 20, 2021 10:02 am
If there's a faster way of rotating the characters I'd like to know.
Some ideas in this mini-challenge thread.
by BigEd
Thu Oct 21, 2021 10:48 am
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

Is there any chance at all that the Pi zero is not getting a solid 5V when running at turbo speed?
by BigEd
Wed Oct 20, 2021 10:38 pm
Forum: programming
Topic: Mini-challenge: Rotating 8-byte character definitions
Replies: 28
Views: 428

Re: Mini-challenge: Rotating 8-byte character definitions

I'd need to think about how that works:

Code: Select all

                            * = $0080
0080   16 70      L0080     ASL $70,X
0082   2A                   ROL A
0083   CA                   DEX
0084   10 FA                BPL L0080
0086   60                   RTS
                            .END
by BigEd
Wed Oct 20, 2021 10:14 pm
Forum: 8-bit acorn software: other
Topic: Sampled Birdsong on a Beeb
Replies: 4
Views: 214

Re: Sampled Birdsong on a Beeb

Remarkable - as a program, and a feat, and a trick!
by BigEd
Wed Oct 20, 2021 8:04 pm
Forum: programming
Topic: Mini-challenge: Rotating 8-byte character definitions
Replies: 28
Views: 428

Re: Mini-challenge: Rotating 8-byte character definitions

Wow! Thanks - run in owlet here.
by BigEd
Wed Oct 20, 2021 6:21 pm
Forum: 8-bit acorn hardware
Topic: Econet to AUN bridge on Raspberry Pi - released
Replies: 531
Views: 14516

Re: Econet to AUN bridge on Raspberry Pi - released

I think our feelings on our experience with PiTubeDirect was that the long tail of latency was to do with shared resources on the chip as a whole, not things the software could control - and that's bare metal, where the software was ours. If so, it's not Linux, it's the Pi. It could be a mix of both...
by BigEd
Wed Oct 20, 2021 5:18 pm
Forum: 8-bit acorn hardware
Topic: Elk with homebrew 68000 second processor
Replies: 76
Views: 2653

Re: Elk with homebrew 68000 second processor

We live in an age when a person can cobble together a 20MHz 68k system with a megabyte of RAM! Splendid.
by BigEd
Wed Oct 20, 2021 3:23 pm
Forum: programming
Topic: Mini-challenge: Rotating 8-byte character definitions
Replies: 28
Views: 428

Re: Mini-challenge: Rotating 8-byte character definitions

Well, for me a mini-challenge is a free-for-all. Hopefully the results will be useful to you, but if not, we're no worse off than if we hadn't asked. For me it's about the ideas. I hope that sits well with you.
by BigEd
Wed Oct 20, 2021 2:16 pm
Forum: programming
Topic: Mini-challenge: Rotating 8-byte character definitions
Replies: 28
Views: 428

Mini-challenge: Rotating 8-byte character definitions

Not too far away Richard asks about sideways fonts: If there's a faster way of rotating the characters I'd like to know. I'm not sure if these clever transposition routines are any help in rotation. But I thought it might be worth asking the coding community here for their ideas. A bit of context: ....
by BigEd
Wed Oct 20, 2021 12:15 pm
Forum: acorn & bbc micro user group (abug) events
Topic: ABUG Dev night #28, Thursday 21st October 2021, 7pm - 10pm (BST)
Replies: 11
Views: 231

ABUG Dev night #28, Thursday 21st October 2021, 7pm - 10pm (BST)

On Thursday, which is presently tomorrow, there will be an ABUG Dev night, at 7, on zoom. (Once again, although hopefully this is relatively rare, I won't be there until 9ish, but hopefully hosts will appear by magic and goodwill.) Come and discuss your Acorn-related dev projects, whether they be cr...
by BigEd
Wed Oct 20, 2021 12:11 pm
Forum: acorn & bbc micro user group (abug) events
Topic: ABUG South Christmas Lunch 11 December 2021 - BOOKING THREAD
Replies: 2
Views: 195

Re: ABUG South Christmas Lunch 11 December 2021 - BOOKING THREAD

Sorry, not for me - but bumping this thread for visibility!
by BigEd
Wed Oct 20, 2021 9:18 am
Forum: general
Topic: Sophie Wilson and BBC BASIC for Windows!
Replies: 1
Views: 187

Re: Sophie Wilson and BBC BASIC for Windows!

It's the Basic of choice - congratulations!

(A little more on the ARM simulator in this thread here.)
by BigEd
Sun Oct 17, 2021 10:22 pm
Forum: 32-bit acorn hardware
Topic: RISCstation 7500
Replies: 11
Views: 306

Re: RISCstation 7500

It's true! But we might also need to guess what number they started at. 1000? 4000?
Serial No.
4343
4426
by BigEd
Sun Oct 17, 2021 9:32 pm
Forum: 32-bit acorn hardware
Topic: RISCstation 7500
Replies: 11
Views: 306

Re: RISCstation 7500

It looks like there might be half a dozen users on this forum with a RISCstation 7500 - if they have serial numbers we could estimate production.

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