Search found 966 matches

by dp11
Tue Jan 21, 2020 11:50 pm
Forum: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: BeebSCSI 7_7
Replies: 172
Views: 8029

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: hardware
Topic: BeebSCSI 7_7
Replies: 172
Views: 8029

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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: hardware
Topic: Emulating (or obtaining!) an ARM Evaluation System
Replies: 10
Views: 426

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: hardware
Topic: New Raspberry Pi to 1MHz bus interface
Replies: 60
Views: 1638

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 7:53 pm
Forum: programming
Topic: Mode 7 flip between pages
Replies: 12
Views: 981

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 8:40 pm
Forum: hardware
Topic: Open source A5000 RAM
Replies: 18
Views: 1270

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 8:35 pm
Forum: hardware
Topic: Open source A5000 RAM
Replies: 18
Views: 1270

Re: Open source A5000 RAM

might as well put all the smt on one side. Looks good.
by dp11
Thu Sep 19, 2019 6:42 pm
Forum: past events & exhibitions
Topic: Acorn World and ABUG meetup, Cambridge 20-22nd September 2019.
Replies: 249
Views: 11512

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 9:40 am
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 41
Views: 1488

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 10:22 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 41
Views: 1488

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 8:33 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 41
Views: 1488

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 6:51 pm
Forum: off-topic
Topic: Odd Peripheral Goings-On With RPi4
Replies: 41
Views: 1488

Re: Odd Peripheral Goings-On With RPi4

Doesn't sound like a heat problem to me.
Elminster wrote:
Sat Sep 07, 2019 3:02 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 9:08 am
Forum: hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 124
Views: 8849

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.
by dp11
Thu Aug 22, 2019 7:45 pm
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

Mesa issue will be fixed in 19.2. They're aiming to have a release ready by the 10th of September. So shortly afterwards there should be a Pi release.
by dp11
Sun Aug 18, 2019 9:38 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

Excellent thanks for letting me know.
by dp11
Sat Aug 17, 2019 5:22 pm
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

It's possible that fix was back ported into the drive raspberry pi released to fix libre office.
by dp11
Sat Aug 17, 2019 12:02 pm
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

The only reason I think the fix is in the latest driver is that libre office works. I will try and investigate.
by dp11
Sat Aug 17, 2019 9:31 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

I'm pretty sure that fix is in the latest driver.
by dp11
Sat Aug 17, 2019 9:13 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

I did miss that thread. Thanks for the pointer
by dp11
Sat Aug 17, 2019 9:02 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

If they are happy to help can they see if the pointer in libre office works. Ie just to confirm that they have the latest driver. I'll ask my friends at pi if they know of anything else.
by dp11
Fri Aug 16, 2019 11:10 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

I don't know about OR and AND, but I suspect they are also fixed. The driver certainly has had the XOR fix for a while now.
by dp11
Fri Aug 16, 2019 11:04 am
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1160
Views: 127714

Re: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)

Pizero will be fine. I don't have all the figure to hand , but PiZero(w) ( ARM1176JZF-S ARMv6 1GHz $5.00 to $10.00 +TAXes ) armcode 6502 : 290MHz RPi3B+ ( Cortex A53 ARMv8 1.4GHz $35.00 + TAXes ) RPi3A+ ( Cortex A53 ARMv8 1.4GHz $25.00 + TAXes ) should work but untested armcode 6502 : 339MHz lib6502...
by dp11
Fri Aug 16, 2019 10:33 am
Forum: emulators
Topic: Raspberry Pi 4
Replies: 22
Views: 1237

Re: Raspberry Pi 4

Sadly the Raspberry Pi 4, running Raspbian Buster, currently has a graphics driver bug (the glLogicOp function is broken) which affects BBC BASIC for SDL 2.0 ; specifically the OR, AND and XOR plotting modes (GCOL 1 to GCOL 4) don't work. This causes issues in the IDE and a number of the supplied e...