Search found 6364 matches

by hoglet
Mon Oct 02, 2017 6:47 am
Forum: software: other
Topic: Emulated discs - a modest proposal
Replies: 16
Views: 514

Re: Emulated discs - a modest proposal

It's not just providing an abstraction for disk access. You also need to consider all the utilities needed to make a SD card filesystem usable, analogous to things you might to physically with a floppy disk, such as: - *DIN (choose a disk and put it in the drive) - *DOUT (remove a disk from the driv...
by hoglet
Sun Oct 01, 2017 9:45 pm
Forum: hardware
Topic: Initialising PiTubeDirect
Replies: 9
Views: 343

Re: Initialising PiTubeDirect

*configure intube for the internal tube, then, as dp11 says, *configure tube to turn it on :) If you only have an internal Co Pro, and nothing external, it's actually more reliable to *CONFIGURE EXTUBE - see this post for why: http://www.stardot.org.uk/forums/viewtopic.php?p=146507#p146507 But as D...
by hoglet
Sun Oct 01, 2017 12:34 pm
Forum: other vintage computer hardware, software and games
Topic: Mystery device on eBay
Replies: 2
Views: 203

Re: Mystery device on eBay

I reckon it must be an Atomic Clock :lol:
by hoglet
Sun Oct 01, 2017 12:06 pm
Forum: hardware
Topic: Electron - Memory Detection Issues with the AP6
Replies: 8
Views: 215

Re: Electron - Memory Detection Issues with the AP6

Here's a test program for this false positive RAM detection: 10 CLS 20 INPUT '"How many NOPs? " N 30 P%=&2000 40[OPT 0 50 .test 60 SEI 70 LDX #&0F 80 .loop 90 LDA #&0C 100 STA &FE05 110 STX &FE05 120 LDA &8008 130 STA &2100,X 140 EOR #&FF 150 STA &8008 1...
by hoglet
Sun Oct 01, 2017 10:50 am
Forum: hardware
Topic: Electron ULA Schematics
Replies: 16
Views: 619

Electron ULA Schematics

Hi all, Edit: Here's Harry's second attempt at scanning these: https://www.dropbox.com/s/xmr9h7srqpucj8l/elk_ula_scan_2017_10_17.pdf?dl=0 As mentioned in this thread , I've been back in contact with Harry Barman, one of the ex-Acorn engineers that worked on the Synertek version of the Electron ULA r...
by hoglet
Sun Oct 01, 2017 9:00 am
Forum: hardware
Topic: Electron - Memory Detection Issues with the AP6
Replies: 8
Views: 215

Re: Electron - Memory Detection Issues with the AP6

The other common element is the Plus 1 Support ROM, and it seems both issues should be fixable in software. The RAM test could be made more robust by testing two locations with opposing values (e.g. 55 and AA). Surely that would exhibit the same symptoms as you would still read the same value back ...
by hoglet
Sun Oct 01, 2017 8:27 am
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

Simon, I've just pushed a new release (2.1) of the BeebSCSI code to github. You've probably thought carefully about this, but just in case.... There was a second use of the 573 in host adapter: https://github.com/simoninns/BeebSCSI/blob/45f2bfe396a1dc56dbb24ffcc6ac3fc0de233ec6/BeebSCSI_CPLD/hostAdap...
by hoglet
Sun Oct 01, 2017 6:53 am
Forum: hardware
Topic: Electron - Memory Detection Issues with the AP6
Replies: 8
Views: 215

Re: BeebSCSI issue with production New AP5

The common element is the Plus 1 - would it make sense to add a pull-up resistor to, probably, just one of the data lines in the Plus 1. My feeling is that's a bit drastic, and might possibly have unforeseen consequences (who knows what existing code might rely on the default behaviour). The MOS Tu...
by hoglet
Sat Sep 30, 2017 9:07 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

I think modifying the serial port init code might work, if there is 10 bytes free: .L8567 JSR L85A4 :\ LDA #&00:STA &0D6A :\ DMB: disable interrupts until we are sure the hardware is present LDA #&93:STA &FC60 :\ LDA #&07:STA &FC60 :\ CMP &FC60:BNE L8597 :\ DMB: readback ...
by hoglet
Sat Sep 30, 2017 8:43 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

My initial thought is an interupt service routine should never return claimed, as it doesn't know that somebody else is waiting for an interupt to be serviced. True, but there would be quite a performance overhead to this, as all non-MOS interrupts would be passed to all ROMs, and then onto the use...
by hoglet
Sat Sep 30, 2017 5:07 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

You should take that little comment out and surround it with the flashing lights it deserves... it's a pretty cool thing to have done :D Nice work! Yes, it is pretty amazing. I've been thinking about this some more and I have a theory now as to what's happening. It's based a few assumptions: - the ...
by hoglet
Sat Sep 30, 2017 4:20 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

Here are the results: - BBC Model B + ADFS 1.33 + Data Centre: test passes - BBC Model B + ADFS 1.30 + BeebSCSI: test passes - Electron + ADFS version "ELK103" + Data Centre: test passes - Electron + ADFS version "ELK100" + BeebSCSI: system hangs during "cc cworld" ......
by hoglet
Sat Sep 30, 2017 2:24 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

A small update. I've been doing some more stress testing of BeebSCSI and for comparison Data Centre. The stress test I've been running is to boot Panos on the Matchbox Co Pro, and then try to compile the "hello world" c program, i.e. just: set dir panostests cc cworld link cworld c,pas cwo...
by hoglet
Sat Sep 30, 2017 2:07 pm
Forum: hardware
Topic: Electron cassette i/o scope trace
Replies: 26
Views: 544

Re: Electron cassette i/o scope trace

Out of interest, do we have any idea who owns the design of the Electron ULA nowadays? Do we know who physically has the design data? Like most 8-bit Acorn things, I don't think anyone official owns it any more (or cares), and most of the original design data is likely lost forever. This sort of th...
by hoglet
Sat Sep 30, 2017 12:16 pm
Forum: hardware
Topic: PS/2 to Master keyboard interface?
Replies: 22
Views: 431

Re: PS/2 to Master keyboard interface?

I accept that some seem to be for sale. However this suggests they were discontinued in at the start of 2013. Did Xilinx, have a change of heart? Have I misunderstood that notice? Are there just piles of the things still sitting in warehouses? That notice refers to the original XC9500 series (5V VC...
by hoglet
Sat Sep 30, 2017 11:31 am
Forum: hardware
Topic: Electron cassette i/o scope trace
Replies: 26
Views: 544

Re: Electron cassette i/o scope trace

Maybe it's worth reaching out to Mr Barman again? I agree it is worth another try contacting Harry Barman: http://www.stardot.org.uk/forums/viewtopic.php?p=7791#p7791 BigEd tried last year, but I think got no response. http://www.stardot.org.uk/forums/viewtopic.php?p=150649#p150649 I've just sent h...
by hoglet
Fri Sep 29, 2017 2:32 pm
Forum: hardware
Topic: Electron cassette i/o scope trace
Replies: 26
Views: 544

Re: Electron cassette i/o scope trace

hicks wrote:Does the square wave appear to work well for saving and loading back in via a physical tape deck?

It does work, but to be completely honest it's not been extensively tested.

Dave
by hoglet
Fri Sep 29, 2017 1:17 pm
Forum: hardware
Topic: Electron cassette i/o scope trace
Replies: 26
Views: 544

Re: Electron cassette i/o scope trace

This post has a scope trace of the ULA cassette output signal:
viewtopic.php?p=150521#p150521

Dave
by hoglet
Fri Sep 29, 2017 1:14 pm
Forum: hardware
Topic: Electron cassette i/o scope trace
Replies: 26
Views: 544

Re: Electron cassette i/o scope trace

I have casIn and casOut working in ElectronFpga. Here's how casOut is implemented: https://github.com/hoglet67/ElectronFpga/blob/master/src/common/ElectronULA.vhd#L707 And here's how casIn is implemented: https://github.com/hoglet67/ElectronFpga/blob/master/src/common/ElectronULA.vhd#L603 I don't kn...
by hoglet
Fri Sep 29, 2017 7:23 am
Forum: hardware
Topic: 27513 and Master ROM cartridge
Replies: 15
Views: 334

Re: 27513 and Master ROM cartridge

Was this the advert?
Morley_Master_AA_Board.jpg

RobC has one of these:
viewtopic.php?p=78609#p78609

Sounds like a second. manual level of paging is added.
by hoglet
Wed Sep 27, 2017 6:00 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

However; it's worth mentioning that the primary design aim of BeebSCSI was to emulate the Domesday set-up. This meant that I followed the physical properties of the SCSI host adapter board as closely as possible. As far as I remember, the data buffering should act just like the logic ICs on the ori...
by hoglet
Wed Sep 27, 2017 4:07 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

Re: BeebSCSI issue with production New AP5

I've been looking into this a bit more. There are several factors at play here, but it's possible there is an issue in BeebSCSI. Specifically, the problem relates to the 1MHz bus data bus, and which edge of the 1MHz bus clock BeebSCSI uses to latch data on a write cycle. There is a 1MHZ bus timing d...
by hoglet
Tue Sep 26, 2017 7:18 pm
Forum: hardware
Topic: Beeb FPGA
Replies: 323
Views: 19347

Re: Beeb FPGA

vanfanel wrote:Can we have a ZX-UNO binary with this updated sn76489 model, please?? [-o<

You'll need to talk to the ZX-UNO people about that...
by hoglet
Tue Sep 26, 2017 4:20 pm
Forum: hardware
Topic: NuLA demos
Replies: 128
Views: 4350

Re: NuLA demos

sbadger wrote:I still get Card? though :-({|= )

Can you do *HELP and *ROMS and report back with the exact output? (a photo would be ideal).

Dave
by hoglet
Mon Sep 25, 2017 4:57 pm
Forum: off-topic
Topic: Cheap USB logic analyser - recommendations?
Replies: 9
Views: 244

Re: Cheap USB logic analyser - recommendations?

@Dave - The thing that concerns me with the DSLogic unit is articulated in the video - the one the reviewer is testing is different (later, better model) than the one on the web site, but he says he ordered the Pro and got this one. Not sure I'd be as lucky! Yes, it does seem confusing. I'm still u...
by hoglet
Mon Sep 25, 2017 12:49 pm
Forum: off-topic
Topic: Cheap USB logic analyser - recommendations?
Replies: 9
Views: 244

Re: Cheap USB logic analyser - recommendations?

Less than £100.. Take a look at the DSLogic Pro: http://www.dreamsourcelab.com/order.html This will do: 16 channels @ 100MHz 8 channels @ 200MHz 4 channels @ 400MHz It also does state analysis @ 50MHz There is a teardown / review here: https://opentechlab.org.uk/videos:009:notes And an article on H...
by hoglet
Sun Sep 24, 2017 8:24 pm
Forum: hardware
Topic: BeebSCSI issue with production New AP5
Replies: 20
Views: 568

BeebSCSI issue with production New AP5

We're seeing some issues with BeebSCSI and the production version of the AP5. Simon, I'm wondering if you have any thoughts on this. It looks like an issue related to reset. The main symptom, after is BREAK is released: - 80% of the time, ADFS works perfectly - 20% of the time, ADFS will hang In the...
by hoglet
Sun Sep 24, 2017 6:18 pm
Forum: acorn atom
Topic: ICE T65/Z80/6809
Replies: 553
Views: 23978

Re: ICE T65/Z80/6809

Was just wondering, (and if I'm overlooking it, apologies but....) how hard it would be to Implement a sort of PoPi (PokePin) command, to set a certain output to 0, or to 1, this to test wiring and level shifters. Space is pretty tight in some of the builds...that's the main issue. If you want some...
by hoglet
Sun Sep 24, 2017 6:03 pm
Forum: off-topic
Topic: Cheap USB logic analyser - recommendations?
Replies: 9
Views: 244

Re: Cheap USB logic analyser - recommendations?

Do you have a budget in mind?
by hoglet
Sun Sep 24, 2017 12:58 pm
Forum: hardware
Topic: BBC B / Datacentre Fault
Replies: 15
Views: 466

Re: BBC B / Datacentre Fault

The only problem I've had with Data Centre was because I routed the ribbon cable underneath the BBC circuit board. After a while (a few years) the ribbon cable got pierced by one of the socket pins. This caused an intermittent short between the 6845 hsync output and NMI, which manifested in all mann...

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