Search found 891 matches

by dp11
Fri Mar 15, 2019 10:12 pm
Forum: off-topic
Topic: Computing pi in a very unusual way
Replies: 7
Views: 252

Re: Computing pi in a very unusual way

This might be the most nutty way of computing PI

https://www.youtube.com/watch?v=HEfHFsfGXjs
by dp11
Wed Mar 13, 2019 12:47 pm
Forum: hardware
Topic: Master audio noise
Replies: 13
Views: 190

Re: Master audio noise

retroclinic is referring to the Main master circuit board and not the PSU.
by dp11
Mon Mar 11, 2019 7:24 pm
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1119
Views: 105140

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

I was thinking of dropping pi 1 , but we could say limit copros to 240Mbytes . I don't really want another build.
by dp11
Mon Mar 11, 2019 6:45 pm
Forum: hardware
Topic: Pi-based Co-Pro on the cheap - 100MHz 6502 for £10? (now 274MHz)
Replies: 1119
Views: 105140

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

It has been on my list to re organise the ram to enable larger memory , but with no actual requirement till now it has been at the bottom of my todo list.
by dp11
Sun Mar 10, 2019 11:03 pm
Forum: programming
Topic: 6502, 65SC12, 65C102, huh?
Replies: 8
Views: 319

Re: 6502, 65SC12, 65C102, huh?

jregel wrote:
Sun Mar 10, 2019 10:50 pm
Does the 6502 emulation provided by the PiTubeDirect support the Rockwell instructions?
Yes it does.
by dp11
Thu Mar 07, 2019 9:24 pm
Forum: software: other
Topic: Own up who has written code the NSA is interested
Replies: 1
Views: 168

Own up who has written code the NSA is interested

The NSA has released one of their reverse engineering tools Ghidra. This not only disassembles 6502 ( and a number of others cpus) but generates C code.
by dp11
Wed Mar 06, 2019 7:15 pm
Forum: hardware
Topic: Beeb 1MHz Bus FPGA Adaptor
Replies: 35
Views: 807

Re: Beeb 1MHz Bus FPGA Adaptor

Dam you have beeten me. I've been planning this for ages
by dp11
Wed Mar 06, 2019 2:40 pm
Forum: hardware
Topic: M3000 vs M5000
Replies: 50
Views: 3633

Re: M3000 vs M5000

Could some kind person point me to the files I need to play some M3000 files? Also could tell me how to play them? The ROM I tried with "filename" LOAD RUN would give a no room error.
by dp11
Tue Mar 05, 2019 7:17 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 97
Views: 3366

Re: BeebSCSI 7_7

It is quite a lot of changes, which is why I'm a little worried about missing something or making a mistake. I'm certain some of the flushes can be removed, but I want it to be safe. Also it might be worth keeping track of multiple open luns then copying between luns would also be fast. As I say ple...
by dp11
Mon Mar 04, 2019 10:22 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 97
Views: 3366

Re: BeebSCSI 7_7

Pull request done. Please test and report back.
by dp11
Mon Mar 04, 2019 2:56 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 97
Views: 3366

Re: BeebSCSI 7_7

I haven't made a pull request yet. As I've been playing to understand and fix the issue, so the code is not the neatest.

The previous commit I made was to fix the transfer program which transfers files from FAT to ADFS.
by dp11
Sun Mar 03, 2019 2:28 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 97
Views: 3366

Re: BeebSCSI 7_7

I've done some work on this issue. Here are my notes , please ignore typos. I logged the SDCARD accesses. Access to the last sectors on ADFS have about 127 SDCARD sector reads compared to the sectors at the beginning of the adfs dsc file. These extra sectors are the file system following the FAT clu...
by dp11
Mon Feb 25, 2019 12:27 am
Forum: hardware
Topic: Strange error when running Snapper on my BBC Master - Solved
Replies: 7
Views: 273

Re: Strange error when running Snapper on my BBC Master

The basic file snapper does the following:

Code: Select all

50 ?&FE6B = &C0 : IF ?&FE64=?&FE64 PRINTTAB(10,10)"IC 69 missing ......"
So if timer1 doesn't change then it say the user via ( 6522) is faulty.
by dp11
Sat Feb 23, 2019 9:31 pm
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 274

Re: help in using JSBeeb to debug code

I didn't ignore it for writes to the Waveform ram and just allocated 4K of RAM instead of 2K. Still no sound comes out ,more debugging todo.
by dp11
Sat Feb 23, 2019 9:18 pm
Forum: software: other
Topic: help in using JSBeeb to debug code
Replies: 11
Views: 274

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: 274

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: 274

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: 469

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: 274

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: 469

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: 469

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: 195

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: 55
Views: 1714

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: 552

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: 552

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: 347

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: 65
Views: 1762

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: 812

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: 1119
Views: 105140

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: 505

Re: BBC Model B Issue 7 video problems

They look like the type that fail so I would do them.