Search found 215 matches

by JannievanZyl
Sun Mar 08, 2020 9:36 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

Hey, did you ever manage to look at the SVI files I sent? I did, and I wasn't able to get a clean decode because of the glitching in the capture files. Yeah, took some traces today again with shorter cables, but still the same issue. But, must say, it still gives lots of useful output. Especially t...
by JannievanZyl
Sun Mar 08, 2020 5:58 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Sat Jan 25, 2020 6:56 pm
Could you ZIP and upload a sample capture file so I can have a play? (Or copy one to somewhere like dropbox)
Dave
Hey, did you ever manage to look at the SVI files I sent?

After a hiatus (don't ask), I'm back at looking at this project. :)
by JannievanZyl
Sun Feb 09, 2020 4:04 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 877
Views: 72809

Re: ICE T65/Z80/6809

bprosman wrote:
Sun Feb 02, 2020 10:20 am
Junior_Computer_Display.zip
/Slightly off-topic :)

My eye just caught the "Junior Computer" bit. In any way related to the Elektor project?
by JannievanZyl
Sat Jan 25, 2020 8:11 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Sat Jan 25, 2020 7:47 pm
What would also be useful would be some kind of disassembly (or assembler listing) for the code being executed on RESET.
Dave
Already in the file I sent you. :)

At least, the ROM listing. I can add a disassembler listing.

/Edit: I put a disasembled listing in the same directory.
by JannievanZyl
Sat Jan 25, 2020 7:18 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Sat Jan 25, 2020 6:56 pm
I have also seen example of RESET looking like this. It's what you get if there is a really slow rising edge (from a large RC) that buffered by a none-schmitt buffer.
Yup, they just use a few inverters. I seriously considered putting a Schmitt gate in there to clean it up. :)
by JannievanZyl
Sat Jan 25, 2020 7:07 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Sat Jan 25, 2020 6:56 pm
Could you ZIP and upload a sample capture file so I can have a play? (Or copy one to somewhere like dropbox)
Dave
Was hoping you would ask! :)

I'll send you the dropbox links.
by JannievanZyl
Sat Jan 25, 2020 6:48 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

You can see here that the /RESET line seems to bounce all over the show before it stabilizes
Z80-reset.png
And here you can see spurious spikes, which I suspect are an artifact created by the logic analyser.
Z80-spikes.png
Could these be the reason behind the errors in the decoded file?
by JannievanZyl
Sat Jan 25, 2020 6:36 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

I ran the first few logs of the Z80 boot sequence but getting some unexpected results. 1. There are a number of errors before the Reset is assumed. 2. Then, the 3F at Addr 0000 is not there in the actual code, rather the first instruction is the JP 7B50h which is decoded as at Addr 0001 but is actua...
by JannievanZyl
Thu Jan 23, 2020 6:20 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

by JannievanZyl
Wed Jan 22, 2020 6:15 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Wed Jan 22, 2020 6:06 pm
This session is very useful for me - I'll go back through this thread and turn some of this into getting started documention on the Wiki. So please keep asking if things are not clear.

Dave
Thanks Dave,

This is a seriously impressive bit of work you - and the other members here - pulled off!
by JannievanZyl
Wed Jan 22, 2020 5:30 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

hoglet wrote:
Wed Jan 22, 2020 3:02 pm
OK, so you'll be using asynchronous mode, in which case you need to connect the CLK signal to Bit 15.
Cool, tx!
hoglet wrote:
Wed Jan 22, 2020 3:02 pm
What speed is your Z80 running at?
The system I need to debug is running at 3.58MHz, a Spectravideo SV-328

BTW, is there a description of the command-line options somewhere?
by JannievanZyl
Wed Jan 22, 2020 2:37 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

Dave,

I'm using the Kingst LA1010. It can capture 16 channels @ 16MHz

http://www.qdkingst.com/en/products

Something I've noticed is that there seems to be xtalk between the different channels, especially if you have many connected up. I was wondering if it is a function of the unshielded cables.
by JannievanZyl
Wed Jan 22, 2020 12:41 pm
Forum: hardware
Topic: Z80 Protocol Decoder
Replies: 213
Views: 9023

Re: Z80 Protocol Decoder

These are the signals that must be captured, correct?: - Data 1 - 8 - /M1 - /MREQ - /IORQ - /RD - /WR - /RST For the file to be properly decoded, must these signals be capture in a specific order? I.e. Probe-1 on the logic analyzer must be a specific signal, etc? And must they be named in a specific...
by JannievanZyl
Sat Jan 18, 2020 2:36 pm
Forum: hardware
Topic: 27xx <--> 28xx
Replies: 0
Views: 246

27xx <--> 28xx

How compatible is a 28xx EEPROM with its equivalent 27xx EPROM? They are pin-compatible, but can one drop a 2864 in the place of a 2764, for example? I wrote two different 28C64s and tested them in place of a 2764 (in a C64 cartridge) and they seem to work but are definitely unstable. So, not sure i...
by JannievanZyl
Sun Jan 05, 2020 4:42 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 877
Views: 72809

Re: ICE T65/Z80/6809

It looks like the wiki does pooint to the /dev tree.

What confused me (methinks) is that I expected a V1.1 for Z80 but it looks like only the 65c02 is on V1.1, the Z80 and 6809 are still on V1.0, correct?
by JannievanZyl
Sun Jan 05, 2020 1:46 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 877
Views: 72809

Re: ICE T65/Z80/6809

Sorry Dave, one last question :)

I see the gerbers on github are v1 and are a few months old (Sep for Z80 and Oct for 6502).

These are the correct ones still, no new updates as per the development you've done since then?
by JannievanZyl
Fri Jan 03, 2020 10:07 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 877
Views: 72809

Re: ICE T65/Z80/6809

Perfect!!

On it! :D
by JannievanZyl
Thu Jan 02, 2020 2:17 pm
Forum: acorn atom and system
Topic: ICE T65/Z80/6809
Replies: 877
Views: 72809

Re: ICE T65/Z80/6809

Dave, just to confirm what is needed to get going, this is my understanding of what I need; 1. Xilinx XC6SLX9 Mini Board -- Is this still the recommended board? (I know there were a story wit level converters, etc.) - https://www.ebay.co.uk/itm/Xilinx-FPGA-Spartan-6-XC6SLX9-Core-Board/111640406811 2...
by JannievanZyl
Sat Nov 30, 2019 9:03 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

mjforbes wrote:
Sat Nov 30, 2019 6:53 pm
1024MAK wrote:
Sat Nov 30, 2019 6:26 pm
They are less common than BBC B, BBC Master and Election machines.

They are common as muck at the moment .. :lol:

M.
Not that you Poms are actually getting around to actually doing something.... :)
by JannievanZyl
Sat Nov 30, 2019 8:29 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

CMcDougall wrote:
Sat Nov 30, 2019 6:46 pm
:shock: ram already socketed, nice
Easy fix then .... =D>

here is a rough estimate of sales of machines:
viewtopic.php?f=42&t=4321#p38163
This is brilliant, tx!!

Any idea on Atom sales?
by JannievanZyl
Sat Nov 30, 2019 8:27 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

1024MAK wrote:
Sat Nov 30, 2019 6:22 pm
[Whenever you get a black screen, it’s always worth seeing if CONTROL-G results in a bleep :wink:
Indeed what I did. And got the beep (pardon the pun! :) ). So was sure the machine is working, was just something with the display.
by JannievanZyl
Sat Nov 30, 2019 6:21 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

Out of interest, from what I read, it seems the BBC+ was a bit of a stop-gap machine before the Master, is that correct?

How long were they on the market and were there any significant sales? I.e. how common are they?
by JannievanZyl
Sat Nov 30, 2019 6:17 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

stephen_usher wrote:
Sat Nov 30, 2019 5:28 pm
S14 plug, made North: North gives white on black video, South gives black on white video. Beware monitor performance in the latter configuration.
In South it just gave me a black screen on both RGB and composite.
by JannievanZyl
Sat Nov 30, 2019 6:15 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

Thanks!

Working perfectly with S14 in North.
working.jpg
by JannievanZyl
Sat Nov 30, 2019 4:43 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

Just managed to recap the PSU now. When I first switched it on, it gave a continuous tone with Cassette And Caps lock permanently on. I saw the RAM was socketed (clearly someone worked on it before) and I tested all the chips. 2 of them failed in my RAM tester, so I replaced them. I actually ended u...
by JannievanZyl
Sat Nov 23, 2019 4:40 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Re: Model B+

Thanks Mark and Mike!

So, same PSU and keyboard, right?
by JannievanZyl
Fri Nov 22, 2019 11:32 pm
Forum: hardware
Topic: Model B+
Replies: 20
Views: 796

Model B+

Been quite a while since I posted here. But have had a number of BBC Model Bs across my bench and have been able to return quite a few into the local community. Found another 7 for repair and distribution today which is pretty cool for South Africa, they're not that common. When I opened them, I fou...
by JannievanZyl
Mon Jun 25, 2018 10:25 pm
Forum: hardware
Topic: Floppy / Stiffy Drive setup
Replies: 21
Views: 1013

Re: Floppy / Stiffy Drive setup

Thanks for the info Chris! So it looks like the Model B defaults to 24ms step time and the Master to 6ms which is closer to what the drive specs say? This is probably because the Model B had a default configuration for an 40-track drive and the Master for an 80-track? So, on the Master I'll leave it...
by JannievanZyl
Mon Jun 25, 2018 10:15 pm
Forum: hardware
Topic: (Yet another) Memory Question
Replies: 69
Views: 3042

Re: (Yet another) Memory Question

As others have suggested, RAM faults would normally give vertical blocks, not diagonal. This is making me suspect something other than the RAM is at fault (or also at fault). Thanks Kazzie and others. I'll get back to this machine in the next day or so and think I'll retake some good quality photos...
by JannievanZyl
Mon Jun 25, 2018 8:46 pm
Forum: hardware
Topic: Floppy / Stiffy Drive setup
Replies: 21
Views: 1013

Re: Floppy / Stiffy Drive setup

I found this table of the init jumpers on the keyboard in the DFS manual.

Since, the drives in my setup are Mitsubishi drives, should I make Link-4?

Will it improve performance, reliability, etc?
keyboard jumpers.JPG
Oh, and...on the BBC Master, are these same settings available?