Search found 1096 matches

by dp11
Wed Mar 18, 2020 9:51 pm
Forum: upcoming (and recent) other events + general event chat
Topic: Virtual ABug?
Replies: 22
Views: 1381

Re: Virtual ABug?

Let's give it ago. Google Hangouts or meets could be used.
by dp11
Tue Mar 17, 2020 10:11 am
Forum: 8-bit acorn hardware
Topic: Help with a test on M5000 required
Replies: 2
Views: 225

Re: Help with a test on M5000 required

Thanks very much for confirming. I suspect it is some sort of bug/ race condition
by dp11
Mon Mar 16, 2020 12:11 am
Forum: 8-bit acorn hardware
Topic: Help with a test on M5000 required
Replies: 2
Views: 225

Help with a test on M5000 required

Could some kind person with a real M5000 do a quick test for me?

Start M5000 playing music. Then do *dump large file e.g. *dump anhf

Does the music stop play a little way into the file?
by dp11
Fri Feb 28, 2020 11:11 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

From what I understand not all frequencies are possible.
by dp11
Fri Feb 28, 2020 5:19 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

What are your overclock settings ? you may need to up the overvoltage setting.
by dp11
Fri Feb 28, 2020 4:00 pm
Forum: 32-bit acorn hardware
Topic: Acorn AKA20 We32206 Floating Point Co-Processor
Replies: 25
Views: 856

Re: Acorn AKA20 We32206 Floating Point Co-Processor

FPEPC only moves results across domains with LD ST instructions so if you do lots of trig one after another you can get a good speed increase.

I don't think I ever tested the AMD so it may not even boot.
by dp11
Fri Feb 28, 2020 3:19 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

have you rebooted ? I think you might have to reboot for it to take effect.
by dp11
Thu Feb 27, 2020 12:48 pm
Forum: 32-bit acorn hardware
Topic: Acorn AKA20 We32206 Floating Point Co-Processor
Replies: 25
Views: 856

Re: Acorn AKA20 We32206 Floating Point Co-Processor

Yes WSS sold it. I have the builds and source code in the loft. I'll dig it out if you are interested.
by dp11
Wed Feb 26, 2020 6:06 pm
Forum: 32-bit acorn hardware
Topic: Acorn AKA20 We32206 Floating Point Co-Processor
Replies: 25
Views: 856

Re: Acorn AKA20 We32206 Floating Point Co-Processor

On the RIscPC I did write the software to using the x86 card as the FPU. So if you have an 586-133MHz card that is probably the fastest FP Acorn machine.
by dp11
Sat Jan 25, 2020 3:14 pm
Forum: 8-bit acorn hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 144
Views: 11494

Re: Raspberry Pi to 1MHz bus interface

Pi1MHz mustn't be late in servicing the FIQ request. From memory the Pi USB interface makes use of the FIQ handler too. It might be possible to use one of the spi network interface chips. Especially as the pi zero doesn't have a network interface.
by dp11
Tue Jan 21, 2020 11:50 pm
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

It should be possible to add the pull up in software on the pi and still only have one build.
by dp11
Sat Jan 18, 2020 7:30 pm
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

Lots of music 5000 links in this thread

viewtopic.php?f=2&t=15780&hilit=Music+5000
by dp11
Sat Jan 18, 2020 11:57 am
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

The nmi and irq will be open collector outputs and so you will need a pullup resistor to see them go high.
by dp11
Sat Jan 18, 2020 12:08 am
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

Good work I assume the diodes for nmi and irq are on the bottom and are the correct way round?
by dp11
Thu Jan 16, 2020 4:34 pm
Forum: 8-bit acorn hardware
Topic: BeebSCSI 7_7
Replies: 229
Views: 11122

Re: BeebSCSI 7_7

Thanks , now fixed on the Pi1MHz build. I'll look at updating to the latest version of FatFS at some point as it have some exFAT fixes.
by dp11
Tue Jan 14, 2020 10:32 am
Forum: 8-bit acorn hardware
Topic: BeebSCSI 7_7
Replies: 229
Views: 11122

Re: BeebSCSI 7_7

Looks like a recent version of ffconf.h hasn't been checked in.

Though I haven't tested Pi1MHz build the code base for Pi1MHz looks okay.
by dp11
Mon Jan 13, 2020 10:05 am
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

I haven't tested the current consumption of the PiZero, but I would expect it to be quite low. HDMI output is disabled. The screen therefore isn't moving large amounts of video data out of RAM. Most of the code sits in cache.
by dp11
Fri Jan 10, 2020 1:04 pm
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

For the audio you don't actually need any resistors. I just had them their to give me options.

I'd suggest you printout your PCB and glue it to a bit of card and see if it fits under the beeb and Master. Remember the 1MHz connector sticks out before it is inserted into the 1MHz bus connector.
by dp11
Wed Jan 08, 2020 6:01 pm
Forum: 8-bit acorn hardware
Topic: Emulating (or obtaining!) an ARM Evaluation System
Replies: 10
Views: 602

Re: Emulating (or obtaining!) an ARM Evaluation System

Do remember the first ARM simulator was written in BASIC on a Beeb.
by dp11
Wed Jan 08, 2020 1:24 pm
Forum: 8-bit acorn hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 160
Views: 7514

Re: New Raspberry Pi to 1MHz bus interface

The master has less space underneath so you might like to check that out. Pi GPIO pins can by high impedance which is why the simple resistor diode level shifter works. Some people will say you need termination, the 1MHz spec says you need termination ( 2K2 from memory ), but you need to terminate a...
by dp11
Thu Oct 17, 2019 8:53 pm
Forum: programming
Topic: Mode 7 flip between pages
Replies: 12
Views: 1290

Re: Mode 7 flip between pages

As it's only 1K the simplest is a fast copy loop. \ (src)=>start of source data LDA #19:JSR OSBYTE :\ Wait for VSync LDX #4:LDY #0 LDA #&7C:STA dst+1:STY dst+0 .loop LDA (src),Y:STA (dst),Y INY:BNE loop:DEX:BNE loop RTS The copy loop needs a little more work I think. It copies the same page 4 times
by dp11
Tue Sep 24, 2019 9:40 pm
Forum: 32-bit acorn hardware
Topic: Open source A5000 RAM
Replies: 18
Views: 1679

Re: Open source A5000 RAM

I'd also add a little decoupling for the buffers easy not to fit if it isn't required.
by dp11
Tue Sep 24, 2019 9:35 pm
Forum: 32-bit acorn hardware
Topic: Open source A5000 RAM
Replies: 18
Views: 1679

Re: Open source A5000 RAM

might as well put all the smt on one side. Looks good.
by dp11
Thu Sep 19, 2019 7:42 pm
Forum: past physical ABug events
Topic: Acorn World and ABUG meetup, Cambridge 20-22nd September 2019.
Replies: 249
Views: 14511

Re: Acorn World and ABUG meetup, Cambridge 20-22nd September 2019.

If anyone needs Pi stuff then there is a Raspberry shop in Cambridge.
by dp11
Sun Sep 08, 2019 10:40 am
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

Okay, but to be clear throttling doesn't turn anything off all that happens is the clock rates are turned down, but not stopped until the temperature recovers.
by dp11
Sat Sep 07, 2019 11:22 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

Doesn't sound like a heat problem to me. Not sure heat was a surprise as early adopters reported they run hot and then start throttling back automagically an£ turning bits off, Can you provide any reference to "turning bits off"? You mean cpu throttling on the pi? I think Beebmaster has already dis...
by dp11
Sat Sep 07, 2019 9:33 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

unlikely to be the issue but there is new beta firmware for the VLI USB chip. might be worth a try...
by dp11
Sat Sep 07, 2019 7:51 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 63
Views: 2382

Re: Odd Peripheral Goings-On With RPi4

Doesn't sound like a heat problem to me.
Elminster wrote:
Sat Sep 07, 2019 4:02 pm
Not sure heat was a surprise as early adopters reported they run hot and then start throttling back automagically an£ turning bits off,
Can you provide any reference to "turning bits off"?
by dp11
Tue Aug 27, 2019 10:08 am
Forum: 8-bit acorn hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 144
Views: 11494

Re: Raspberry Pi to 1MHz bus interface

Audio via the 1MHz bus is a bit noisy, but does make M5000 nice and easy to try. One of the bigger Pis with an audio jack gives stereo and better quality.

I'm sorry I will get around to sorting out the email/ PMs I have from people.

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