Search found 487 matches

by simoni
Tue Oct 09, 2018 8:24 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

I'm seeing exactly the same problem "exactly the same" as in long access times or "exactly the same" as in log access times and 2C disc errors? I can see from the logs you provided (thanks!) that the final read6 command in the log takes 1.26 seconds to seek and retrieve the data from the SD card - ...
by simoni
Mon Oct 08, 2018 12:07 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

or 5) The computer ;)
by simoni
Mon Oct 08, 2018 11:50 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

At first it was considerably worse, waiting 10 seconds part way through my read test and then giving disc error 2C to every subsequent access, and not correcting itself till either the card was reinserted or the board powered off. It seems to have settled down now, but the sluggish read times persi...
by simoni
Sun Oct 07, 2018 6:24 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

BeebSCSI is open-source - for details of how the sense and translate commands work take a look at this: https://github.com/simoninns/BeebSCSI/blob/master/BeebSCSI_AVR/BeebSCSI_AVR/scsi.c#L1308 The code is commented; so it should be easy to understand. As for the slow-down - well SD card access times...
by simoni
Sun Oct 07, 2018 4:24 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

It doesn't fit under a Master of course, so I had to use a 34-way extension cable. It's a bit unfortunate that the board gets in the way of the lugs on an extension cable, so in the end I had to use one without lugs. I also had to bend the power pins up a bit to get anything to plug into them. The ...
by simoni
Tue Sep 25, 2018 7:53 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

If there is an incompatibility I'd put good money on it not being the BeebSCSI - it was very carefully designed to follow Acorn's 1MHz bus application note and uses the Acorn specified page addresses for SCSI; other devices (especially IDE devices) illegally use the reserved SCSI page FC mapping. As...
by simoni
Tue Sep 25, 2018 7:37 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

I'm glad you are having some success with the boards :) There are lots of BeebSCSIs in use, and it acts exactly like a real Winchester. So if you are having issues it's 99.99% sure it isn't the BeebSCSI design - far more likely to be incorrect assembly or a dodgy Beeb/connector. It works fine with t...
by simoni
Fri Sep 21, 2018 3:58 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

I've never quite worked out why that happens sometimes - I guess it could be something to do with the pre-installed bootloader interfering with the fuse programming; still, you are up and running - once you have the solid flash, you are in BeebSCSI bootloader land - just pop the BEEBSCSI.bin on an S...
by simoni
Thu Sep 20, 2018 8:49 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

Sometimes the AVR can be a little odd. Try programming it first and then setting the fuses. It can jiggle it into working. On the other hand it could be the programmer; you could also try lowering the programming clock speed.
by simoni
Fri Sep 14, 2018 5:11 am
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

I've finally got around to making a full write-up for this project; it's available from the following link: https://www.domesday86.com/?page_id=2407 I have one of these boards running in a real Domesday system - works perfectly (and probably a lot more reliable than the original since all the parts ...
by simoni
Thu Sep 13, 2018 1:35 pm
Forum: hardware
Topic: Philips VP415 Front-loader replacement module
Replies: 0
Views: 215

Philips VP415 Front-loader replacement module

If you're repairing or restoring Domesday systems (or work with one of the museums that maintains a system), this project should be of interest. It's a drop-in replacement for the front-loader switches (and loader motor H-bridge) and replaces the original Philips board which was prone to damage as t...
by simoni
Mon Aug 20, 2018 4:27 pm
Forum: hardware
Topic: SCSI/HADFS/ADFS/Partitions
Replies: 8
Views: 413

Re: SCSI/HADFS/ADFS/Partitions

On question 1 - afaik there is no partition support (certainly not in 8-bit ADFS). The only thing it supports is multiple LUNs through a single SCSI-1 controller. BeebSCSI does all of this via emulation of SCSI towards a single SD card that has the LUN images on it. If you want to make a single SCSI...
by simoni
Fri Aug 17, 2018 5:49 am
Forum: hardware
Topic: Broken New AP5 Fixed & Electron Mouse testing
Replies: 75
Views: 2980

Re: Broken New AP5 Fixed & Electron Mouse testing

SmallyMouse2 doesn't require a PS/2 compatible mouse - it has real USB support. Any mouse should work, even wireless ones. The only hardware reason SmallyMouse wouldn't work with something (assuming the connections are correct) is power - USB requires 5V. The interface to the computer is basically a...
by simoni
Mon Aug 06, 2018 11:10 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

I've now added a 3D printable case for the BeebSCSI board to the Github (both OpenSCAD and STL files are available). The case is completely reconfigurable in openSCAD (you can change the size, ports and decoration): 1.jpg Note that the BeebSCSI board requires all connectors to be right-angle (except...
by simoni
Sun Jul 22, 2018 8:15 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

In the 7_7 design both the CPLD and AVR are joined in a JTAG chain, so there is only one JTAG header for both chips. The reason there are two headers labelled JTAG is that one is a standard 10 pin JTAG header suitable for both AVR and Xilinx programmers and the other is a tag-connect header. Tag-con...
by simoni
Fri Jul 20, 2018 7:28 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

I was following some good advice from a fellow Acorn fan who worked for a company that did pick and place assembly. Placing the fiducials in the schematic helps them to identify the markers during the process. Also, as Daniel states; it's generally a good idea to have everything in the schematic as ...
by simoni
Fri Jul 20, 2018 10:38 am
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

Fiducials are alignment markers used for board production when using pick and place machines - it is not a 'component' that needs to be purchased; it's an optical marker on the PCB surface. https://en.wikipedia.org/wiki/Fiducial_marker#Printed_circuit_boards The board contains 3 such markers (F1, F2...
by simoni
Sun Jul 15, 2018 1:02 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

There's really only one type of cable connector; so it's just the type of socket on the BeebSCSI that can be varied. Sounds like you have a plan now though :)
by simoni
Sun Jul 15, 2018 12:13 pm
Forum: hardware
Topic: BeebSCSI 7_7
Replies: 161
Views: 7246

Re: BeebSCSI 7_7

You can purchase either a straight IDC socket, or an angled IDC socket. If you use an angled IDC it fits flush to the board over the two rear mounting holes (pictured of both configurations are shown on the BeebSCSI hardware page). The 7_7 board is designed to be cased, so you can either: Use a stra...
by simoni
Tue Jul 10, 2018 1:05 pm
Forum: hardware
Topic: SCSI / SCSI II adapaters?
Replies: 11
Views: 914

Re: SCSI / SCSI II adapaters?

The host adapter cards are specific to ADFS so the logic is fixed. The only variance is the external card and the internal (VFS) adapter for the Master (as the glue-logic is different). Schematics and a description of the glue-logic design is available here: https://www.domesday86.com/?page_id=64 Yo...
by simoni
Tue Jul 10, 2018 10:49 am
Forum: hardware
Topic: Sound Out
Replies: 4
Views: 494

Re: Sound Out

Get a 15 quid Gotek, flash it with the flashfloppy firmware and use it as a second drive. Instant ADFS image files on a USB stick :)
by simoni
Tue Jul 10, 2018 9:52 am
Forum: hardware
Topic: BBC 2nd Processors: Ribbon cable connectors
Replies: 5
Views: 470

Re: BBC 2nd Processors: Ribbon cable connectors

The ribbon cable inside the 2nd processor is attached using a header - you can't simply pull it out (if you remove the ribbon cable you will need to replace the header as it's a one-use component). If you need to replace the ribbon then the best thing to do is desolder the existing header and replac...
by simoni
Tue Jul 10, 2018 9:26 am
Forum: hardware
Topic: SCSI / SCSI II adapaters?
Replies: 11
Views: 914

Re: SCSI / SCSI II adapaters?

Well, anything is possible with some work :) The main issue with SCSI-2 (and, in fact, some SCSI-1) is the sector size is often 512 bytes rather than the 256 bytes used by the original ADFS. Unless the drive controller uses 256 it's going to be tough to make it work on a Beeb (although the Master co...
by simoni
Sat Jul 07, 2018 10:43 am
Forum: hardware
Topic: Broken New AP5 Fixed & Electron Mouse testing
Replies: 75
Views: 2980

Re: Broken New AP5 Fixed & Electron Mouse testing

SmallyMouse2 uses the AMX pin-out (as this works for AMX utilities as well as Domesday). The board also accounts for the extra sensitivity in USB mice and intelligently changes this to the appropriate quadrature rates. On the 'user-port' side of things, the output is simply quadrature - just like a ...
by simoni
Mon Jul 02, 2018 4:11 am
Forum: hardware
Topic: TMS6100 Acorn Speech Upgrade PHROM Emulator
Replies: 21
Views: 2734

Re: TMS6100 Acorn Speech Upgrade PHROM Emulator

The DIP Atmega32 and the SMD Atmega32uX range of chips are not the same iirc - your programmer will need to support the Atmega32u2 or Atmega32u4 directly (as those two chips are the same from a programming point of view). How you program depends on what OS you have and what support there is for your...
by simoni
Sun Jul 01, 2018 8:17 pm
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

I've finally received the missing parts and finished building the board. The finished board was installed into a Master and connected to a Phillips VP415. VFS checks out ok and I was able to boot the Domesday LaserDiscs without issue; so the board is now confirmed as working. The only minor issue wa...
by simoni
Tue Jun 19, 2018 3:06 pm
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

There's no arbitration of the bus in ADFS. The host ID is always 1 and it supports 1 target with 4 LUNs (8 LUNs under VFS).
by simoni
Tue Jun 19, 2018 1:27 pm
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

The SCSI-1 interface implemented by ADFS is really SASI. It was made at a point where SASI was being transformed into SCSI. It's probably why little original documentation exists. The Adaptec ACB-4000 documentation (which is widely available) contains the specific implementation used by Acorn (as it...
by simoni
Tue Jun 19, 2018 11:27 am
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

As part of the Domesday86 project I've produced extensive documentation on the SCSI-1 protocol used by ADFS and VFS. There is also BeebSCSI which emulates both SCSI-1 hard drives and the VP415 LaserVision player used by Domesday. BeebSCSI also includes a verilog implementation of both the internal A...
by simoni
Tue Jun 19, 2018 3:58 am
Forum: hardware
Topic: Acorn Domesday AIV SCSI Boards - now free...
Replies: 30
Views: 2392

Re: Acorn Domesday AIV SCSI Boards - now free...

The board is a replica of the Acorn AIV SCSI adapter. It's designed to connect to PL12 and be mounted inside the BBC Master (if you look up the AIV SCSI board original - this board does exactly the same). The logic of the AIV SCSI adapter and the original BBC 1MHz bus adapter is not the same, so the...