Search found 967 matches

by dp11
Sat Feb 23, 2019 9:18 pm
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 672

Re: help in using JSBeeb to debug code

A slight guess but when ample sets up the waveforms it appears that there are 14 waveforms written following the address pattern.
by dp11
Sat Feb 23, 2019 8:52 pm
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 672

Re: help in using JSBeeb to debug code

Wow Excellent, Thanks.

It has shown me that M500 Ample software thinks the Waveform ram is at slightly different address from what was previously documented.

Waveform 0 :3000 -> 307F
Waveform 1 :3180 -> 31FF
waveform 2 :3200 -> 327F
Waveform 3 : 3380 - > 33FF
etc
by dp11
Sat Feb 23, 2019 10:43 am
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 672

Re: help in using JSBeeb to debug code

I'm really after logging and an entire page.
by dp11
Sat Feb 23, 2019 10:27 am
Forum: emulators
Topic: B-em on OSX with M5000 support
Replies: 14
Views: 1012

Re: B-em on OSX with M5000 support

Looking into this even more, the &FE doesn't exist in real hardware and if the compiler is very good it should be optimised away . Bit 0 is the disable bit. If it is set the FREQ macro isn't used. If bit 0 is clear then the macro is use and the &FE is implied.
by dp11
Fri Feb 22, 2019 11:00 pm
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 672

help in using JSBeeb to debug code

Could some kind person help me out. In Jsbeeb would like to trap all writes to an area of memory ( say a page) and log these to either a window or a file . e.g. Write address &3000 = &12 Write address &3012 = &54 Write address &3018 = &AB Or if anyone has a better emulator to do it in I'm happy to c...
by dp11
Mon Feb 18, 2019 11:34 pm
Forum: emulators
Topic: B-em on OSX with M5000 support
Replies: 14
Views: 1012

Re: B-em on OSX with M5000 support

I think the frequency could be wrong if that bit gets set by the computer as the emulation clears it.
by dp11
Mon Feb 18, 2019 11:16 am
Forum: emulators
Topic: B-em on OSX with M5000 support
Replies: 14
Views: 1012

Re: B-em on OSX with M5000 support

I think I have also found a bug in the M5000 emulation :

https://github.com/stardot/b-em/issues/75
by dp11
Fri Feb 15, 2019 10:54 pm
Forum: programming
Topic: Unable *SAVE *LOAD ASM to 0D00 in BeebEm
Replies: 5
Views: 497

Re: Unable *SAVE *LOAD ASM to 0D00 in BeebEm

0D00 is used be the disc filing system as the NMI handler, this is on any Beeb not just the emulator.
by dp11
Tue Feb 12, 2019 7:15 pm
Forum: off-topic
Topic: Retro upgrades, value for money, eBay & why bother?
Replies: 58
Views: 3360

Re: Retro upgrades, value for money, eBay & why bother?

Just to add to time , there is much planning and thinking that go into projects and even just buying and selling bits all takes time. Debugging projects takes time and sometimes extra equipment that cost money.
by dp11
Tue Feb 05, 2019 3:47 pm
Forum: software: other
Topic: BBC *Status Command (and odd characters)
Replies: 24
Views: 1217

Re: BBC *Status Command (and odd characters)

The report giving (c) 1986 is also interesting. I think more details on the exact machine and what it has fitted would be useful.
by dp11
Tue Feb 05, 2019 3:33 pm
Forum: software: other
Topic: BBC *Status Command (and odd characters)
Replies: 24
Views: 1217

Re: BBC *Status Command (and odd characters)

That *status command isn't a natural BBC command. That one comes from a ROM . Do you know/ can you find out which version of the ROM is being used.
by dp11
Sun Feb 03, 2019 12:37 pm
Forum: hardware
Topic: Tube port fault?
Replies: 7
Views: 640

Re: Tube port fault?

Can you post some photos of what you are doing?
by dp11
Sun Jan 27, 2019 6:31 pm
Forum: hardware
Topic: New ROM / RAM Expansion Board for BBC B
Replies: 93
Views: 5342

Re: New ROM / RAM Expansion Board for BBC B

I reality square corners are fine on DDR3. A number of people have done test boards and can't really measure the difference . Curves are nicer to look at and can increase track density and keep track lengths down, but many CAD systems struggle with curves. The most important thing for signal integri...
by dp11
Wed Jan 23, 2019 12:56 am
Forum: hardware
Topic: Econet File Server Issues with PiTubeDirect
Replies: 29
Views: 1306

Re: Econet File Server Issues with PiTubeDirect

Not meant to be negative but a few bugs in the code have been fixed over the years so B-em etc may still have them.
by dp11
Thu Jan 03, 2019 2:51 pm
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1160
Views: 129250

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

being bare metal we don't support device tree.

A light pipe would be the simplest way. In real use I don't think most people use the LED.
by dp11
Wed Jan 02, 2019 11:47 pm
Forum: hardware
Topic: BBC Model B Issue 7 video problems
Replies: 16
Views: 824

Re: BBC Model B Issue 7 video problems

They look like the type that fail so I would do them.
by dp11
Wed Jan 02, 2019 1:59 pm
Forum: hardware
Topic: Morley RAMDisc Documentation?
Replies: 5
Views: 515

Re: Morley RAMDisc Documentation?

well spotted .
by dp11
Wed Jan 02, 2019 12:57 am
Forum: hardware
Topic: Morley RAMDisc Documentation?
Replies: 5
Views: 515

Re: Morley RAMDisc Documentation?

Also the morley101 rom looks a little short . BD00 onwards looks missing to me.

http://mdfs.net/System/ROMs/Filing/RAM/

Something to do with backup is unlikely to work.
by dp11
Mon Dec 31, 2018 1:35 am
Forum: hardware
Topic: Morley RAMDisc Documentation?
Replies: 5
Views: 515

Morley RAMDisc Documentation?

Does anyone have the actual documentation for the Morley RAMDisc ? The FRED addresses appear incomplete/incorrect on http://mdfs.net/Docs/Comp/BBC/Hardware/FREDAddrs Looking at the ROM I see : FCC0 Low page address FCC1 only 0 and FF are written to it. When read it is anded with &7F and then checked...
by dp11
Sat Dec 29, 2018 8:30 pm
Forum: general
Topic: Morecambe & Wise restored using BBC BASIC!
Replies: 60
Views: 3602

Re: Morecambe & Wise restored using BBC BASIC!

+1 as the kids say
by dp11
Sun Dec 23, 2018 12:45 am
Forum: hardware
Topic: Raspberry Pi to 1MHz bus interface
Replies: 135
Views: 9664

Re: Raspberry Pi to 1MHz bus interface

Sorry life has got in the way. 1st PCB assembled and tested on a Master. Code written to emulated Acorn Paged RAM expansion and http://www.sprow.co.uk/bbc/ramdisc.htm . I now have 16Mbytes on the 1MHz bus with a PiZero. :)
by dp11
Sun Dec 02, 2018 1:49 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 855
Views: 51155

Re: RGB to HDMI using a Pi Zero and a small CPLD

Nothing from me needs to be in the next release. I like your new psync code.
by dp11
Wed Nov 28, 2018 1:41 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 855
Views: 51155

Re: RGB to HDMI using a Pi Zero and a small CPLD

I think if OSD_update_fast was in assembler we might be able to improve performance . *word_ptr |= *map_ptr; word_ptr++; map_ptr++; *word_ptr |= *map_ptr; word_ptr++; I think in assembler we can use ldm / stm which might improve memory performance.
by dp11
Mon Nov 26, 2018 5:50 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 855
Views: 51155

Re: RGB to HDMI using a Pi Zero and a small CPLD

Nothing Important from me.
by dp11
Mon Nov 26, 2018 12:45 am
Forum: off-topic
Topic: Totally O/T External Domestic Wiring
Replies: 13
Views: 785

Re: Totally O/T External Domestic Wiring

ceiling rose ... All the reds connect together. Argh!!!! NO NO NO!!! That results in the light being permanently on, and the switch becoming a "BLOW FUSE NOW!" activator. Ignore the colours, connect by function: I think if you read the whole paragraph you will find it is is correct. I don't define ...
by dp11
Mon Nov 26, 2018 12:22 am
Forum: emulators
Topic: Can someone try some simple 6522 VIA queries for me on a real BBC?
Replies: 34
Views: 1847

Re: Can someone try some simple 6522 VIA queries for me on a real BBC?

Thats very good. The C based 6502 in the PiTube direct is much slow. Hand optimised 6502 on a 1GHz ARM is about 290MHz I bet the self modifying code makes things fun :) thats why i haven't gone down the JIT route ClockSP adjusts its run time depending on how fast the machine is. Does JITing stop the...
by dp11
Sun Nov 25, 2018 9:49 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 855
Views: 51155

Re: RGB to HDMI using a Pi Zero and a small CPLD

a few more untested cycles removed committed
by dp11
Sun Nov 25, 2018 9:09 pm
Forum: off-topic
Topic: Totally O/T External Domestic Wiring
Replies: 13
Views: 785

Re: Totally O/T External Domestic Wiring

In some of my light fittings there are up to three red wires and two black ones as well as earths. In a standard UK house lighting wiring ceiling rose there will be three reds , three backs, three earths ( if earthed) , plus the wires to the light. All the reds connect together ( But not any wires ...
by dp11
Sun Nov 25, 2018 12:23 pm
Forum: emulators
Topic: Can someone try some simple 6522 VIA queries for me on a real BBC?
Replies: 34
Views: 1847

Re: Can someone try some simple 6522 VIA queries for me on a real BBC?

scarybeasts wrote:
Sun Nov 25, 2018 10:04 am
I'm writing a new BBC emulator as a side project to see how fast emulation can go (spoiler: about 8Ghz worth of 6502 on my 2Ghz Intel laptop so far).
Are you JITing?

Does the core pass the Dorman tests ?

Can you run the CLOCKSP benchmark program ?
by dp11
Sun Nov 25, 2018 12:10 pm
Forum: hardware
Topic: RGB to HDMI using a Pi Zero and a small CPLD
Replies: 855
Views: 51155

Re: RGB to HDMI using a Pi Zero and a small CPLD

opps , must stop doing code late at night. Now fixed.