Beebs and SCSI Hard disks.....

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Prime
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Beebs and SCSI Hard disks.....

Post by Prime » Sun Jan 02, 2011 1:07 pm

Ok couple of questions regarding SCSI hard disks.

1) What bridge boards where commonly used with the Beeb (and other beeb related stuff like the MDFS) ?

2) I have an Atker (I think) 1MHz bus->SCSI board, I presume that this would work with standard ADFS with a suitable drive or bridge board. If so can I use the same program to format the drive as to format the CF/IDE drive ?

3) What is the block size ? I seem to remember it being 256 bytes rather than the more common 512, which is what prevents modern drives from being used.

Cheers.

Phill.

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Re: Beebs and SCSI Hard disks.....

Post by station240 » Sun Jan 02, 2011 2:15 pm

1) There is a commonly used Adaptec ACB 4000 "SCSI to ST-506" bridge board. The MDFS uses straight scsi drives, which are proving hard to get.

2a) Yes, the Atker seems to be a copy of the Acorn board (I have another 3rd party board myself)
2b) Unsure, some changes made to format larger drives and IDE itself. JGH would know more I suspect.

3) Yes 256 byte sectors. While I found some software that can reprogram SCSI drives to use those sector sizes, I'm yet to get any drives that don't barf at the commands to change things.

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Re: Beebs and SCSI Hard disks.....

Post by jgharston » Sun Jan 02, 2011 6:54 pm

Prime wrote:2) I have an Atker (I think) 1MHz bus->SCSI board, I presume that this would work with standard ADFS with a suitable drive or bridge board. If so can I use the same program to format the drive as to format the CF/IDE drive ?
If you're talking about HDInit, then no, it specifically talks to the IDE hardware. However, there are two commented out lines that call the ADFS API instead that I put in to be able to fast-wipe floppies:

Code: Select all

 2130 DEFPROCwrite(sec%,drv%):cmd%=wr%:REM IFdrv%>3:PROCwriteX(sec%,drv%):E.
 2140 DEFPROCread(sec%,drv%):cmd%=rd%:REM IFdrv%>3:PROCreadX(sec%,drv%):E.
If you remove the REMs and change the code to:

Code: Select all

 2130 DEFPROCwrite(sec%,drv%):cmd%=wr%:PROCwriteX(sec%,drv%):ENDPROC
 2140 DEFPROCread(sec%,drv%):cmd%=rd%:PROCreadX(sec%,drv%):ENDPROC
you can initialise floppies and SCSI drives. At some point I may incorporate this as an option into HDInit.
Note that HDInit, as it name explies, initialises a hard drive, it does not format it. It writes an empty free space map and root directory into the first seven sectors.

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.25
(C) Copyright J.G.Harston 1989,2005-2015
>_

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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Thu Jan 06, 2011 8:50 pm

The Adaptec bridge boards appear to be the standard ones. Acorn Winchester Discs used the Adaptec ACB4000A which is an MFM board (33 sectors per track). Drives like Akhter and Technomatic ones used the ACB4070 which is an RLL board (47 sectors per track). These aren't interchangeable and the ACB4070 doesn't have an MFM option, which would have been handy. If you read the manual when it talks about converting from an ACB4000 to an ACB4070 it contains the hilarious line that all you need to do is "re-format the drive".

The only other bridge board I've seen is the Xebec S1410A which has a major drawback in not coding the drive geometry onto the disc, so it has to be told what sort of drive it's dealing with every time you press BREAK.

There are others which are supposed to work, including a Western Digital one, but I've never come across one; all the WD type controller boards I've seen have been PC ISA card variants.

These bridge boards are for ST506 type drives which require the separate Winchester controller. In theory, it's possible to connect a SCSI drive straight to an Acorn or Akhter host adapter and make it work, but I've had very little success with this (as I may have mentioned in about 200 other threads on here) over the last 8 or 9 years.

Some drives definitely work, including the Rodime RO652 which is used in the FileStore E20, and the Syquest SQ555 44MB cartridge drive (but not the 200MB one) and a few early Seagate ones like the ST225N and ST157N.

One problem appears to be with what to do with pin 34 of the SCSI connector, because the Acorn implementation sends 5V, which most drives aren't expecting, so the cable melts. I've got round this problem recently by cutting the wire in the SCSI ribbon cable, but I think I'm also supposed to do something with the cut wire which I haven't fathomed yet.

One thing I can confirm, having tried this over Christmas for the first time since 2006, is that the Domesday VP415 will work with a host adapter board connected to the 1MHz bus. I successfully read data off an LV-ROM disc under ADFS using this method, although the data was slightly garbled, which I haven't got to the bottom of yet. I'm wondering if VFS does something to the data from the disc which ADFS doesn't do.

I had to cut pin 34 on the cable I was using, though, because initially the cable started to get very hot, so I turned everything off pretty quick to stop my laserdisc dissolving.
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Re: Beebs and SCSI Hard disks.....

Post by Prime » Fri Jan 07, 2011 9:20 am

BeebMaster wrote:The Adaptec bridge boards appear to be the standard ones. Acorn Winchester Discs used the Adaptec ACB4000A which is an MFM board (33 sectors per track). Drives like Akhter and Technomatic ones used the ACB4070 which is an RLL board (47 sectors per track). These aren't interchangeable and the ACB4070 doesn't have an MFM option, which would have been handy. If you read the manual when it talks about converting from an ACB4000 to an ACB4070 it contains the hilarious line that all you need to do is "re-format the drive".
Yeah I used to have one of those I think it was the ACB4070, I guess once the drive had been formatted the beeb would have just seen it as a big block os sectors (as this is how SCSI works).

As for re-formatting the drive well yes that's true from a cirtain point of view, the drive will work if you re-low level format it, yes you'd also have to high level format it as well with your filesystem, and transfer files back onto it :)
The only other bridge board I've seen is the Xebec S1410A which has a major drawback in not coding the drive geometry onto the disc, so it has to be told what sort of drive it's dealing with every time you press BREAK.
I have one of those in my XW40 for my RM Nimbus, though at least the Nimbus encodes the geometry in the first block of the disk, so that when dos boots it knows how bit the drive is :) I'm supprised ADFS does not do this.
There are others which are supposed to work, including a Western Digital one, but I've never come across one; all the WD type controller boards I've seen have been PC ISA card variants.

These bridge boards are for ST506 type drives which require the separate Winchester controller. In theory, it's possible to connect a SCSI drive straight to an Acorn or Akhter host adapter and make it work, but I've had very little success with this (as I may have mentioned in about 200 other threads on here) over the last 8 or 9 years.

Some drives definitely work, including the Rodime RO652 which is used in the FileStore E20, and the Syquest SQ555 44MB cartridge drive (but not the 200MB one) and a few early Seagate ones like the ST225N and ST157N.
Yeah that's what I thought, I guess support for 256 byte sectors was dropped as pretty much everything these days is 512 byte, even things back in the day like the Spectrum +3 and the Amstrad machines used 512 byte sectors....
One problem appears to be with what to do with pin 34 of the SCSI connector, because the Acorn implementation sends 5V, which most drives aren't expecting, so the cable melts. I've got round this problem recently by cutting the wire in the SCSI ribbon cable, but I think I'm also supposed to do something with the cut wire which I haven't fathomed yet.
That's usefull to know why the hell Acorn chose to do that is a mystery, pin 34 is marked as gnd on all the SCSI/SASI documentation that I have seen changing it to a voltage was just asking for trouble. Anyway I've added a jumper to pin 34 of my SCSI<->IDE board design so that at least it can be disconnected easily.

So from an point of view of my board emulating the Adaptec board would probably be the best thing to do ? That's actually reasonably good news as I have the hardware manual for the ACB40x0 series.

Does the software that would be used to format and configure tha Adaptec drives exist on the net somewhere ? I did have a quick look on mdfs.net but couldn't see it......

Cheers.

Phill.

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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Fri Jan 07, 2011 11:16 am

Prime wrote:
The only other bridge board I've seen is the Xebec S1410A which has a major drawback in not coding the drive geometry onto the disc, so it has to be told what sort of drive it's dealing with every time you press BREAK.
I have one of those in my XW40 for my RM Nimbus, though at least the Nimbus encodes the geometry in the first block of the disk, so that when dos boots it knows how bit the drive is :) I'm supprised ADFS does not do this.
ADFS doesn't get involved in drive geometry, it expects the free space map and root directory to be on the first 7 sectors of the disc and it's up to the controller to go and find them. There was a later ROM version for the Xebec controller which coded the geometry in the first track of the disc but I haven't tracked it down yet.
Prime wrote: Yeah that's what I thought, I guess support for 256 byte sectors was dropped as pretty much everything these days is 512 byte, even things back in the day like the Spectrum +3 and the Amstrad machines used 512 byte sectors....
The Adaptec board can support 256, 512 or 1024 bytes per sector and you can get the Beeb to format a drive to these specifications. It's not that it isn't possible to do it, it's just that ADFS doesn't like it unless it's a 256 byte sector. I think I'll have a go at some point formatting a 512 bps drive and see what ADFS makes of it. I know I've done it before but I don't think I came up with anything conclusive.

As ADFS has been patched to work with IDE drives formatted to 512 bytes per sector, hopefully somebody will be able to come up with a patch for SCSI/SASI drives as well.
Prime wrote: So from an point of view of my board emulating the Adaptec board would probably be the best thing to do ? That's actually reasonably good news as I have the hardware manual for the ACB40x0 series.

Does the software that would be used to format and configure tha Adaptec drives exist on the net somewhere ? I did have a quick look on mdfs.net but couldn't see it......
The Adaptec manual is very good, not just as a specific product manual but as a general introduction to early SCSI. The usual bit of software to use with Adaptec boards is Acorn's Superform which should be floating about somewhere.

Basically, what happens is that you send a Mode Select command to the controller informing it of the drive geometry, interleave, stepping speed, etc. and then you do a Format Entire Media sending in a defect list if there are any bad sectors on the front of the drive. Then you Verify, translate any bad sectors into their physical location on the drive and Format again with the updated defect list and repeat until you get a verify without any errors.

That much is in the Adaptec manual, and could be put together without too much trouble from scratch, although it's all done for you in Superform. The next bit is to write the ADFS free space map and root directory, which is a bit involved and is probably best to snaffle it from Superform.
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Re: Beebs and SCSI Hard disks.....

Post by Prime » Fri Jan 07, 2011 6:24 pm

BeebMaster wrote: ADFS doesn't get involved in drive geometry, it expects the free space map and root directory to be on the first 7 sectors of the disc and it's up to the controller to go and find them. There was a later ROM version for the Xebec controller which coded the geometry in the first track of the disc but I haven't tracked it down yet.
Humm that should be on the first track of the drive whatever the geometry, however I guess beyond that if the geometry is wrong then ADFS will access what it asumes is block X and it's actually accessing a totally different block.

I could pull out the XW40 and see if I could dump the rom just in case, it is just an EPROM, so I should be able to read it with my programmer.
The Adaptec board can support 256, 512 or 1024 bytes per sector and you can get the Beeb to format a drive to these specifications. It's not that it isn't possible to do it, it's just that ADFS doesn't like it unless it's a 256 byte sector. I think I'll have a go at some point formatting a 512 bps drive and see what ADFS makes of it. I know I've done it before but I don't think I came up with anything conclusive.
Depends on how closeley ADFS follows the SCSI spec, after all it's the drive (or bridge board) that controls how many bytes are sent / recieved, so on a read it may end up reading 512 bytes and either wrapping on the page and overwriting the first 256 with the second, or just overwriting the next page.
As ADFS has been patched to work with IDE drives formatted to 512 bytes per sector, hopefully somebody will be able to come up with a patch for SCSI/SASI drives as well.
But the IDE interfaces cheat :) as IDE is a 16 bit interface it expects 256 x 16bit words, the IDE interfaces* only have the bottom 8 bits connected and so can still use the 256 cycle loop.

*Most IDE interfaces are only 8 bit, I believe the one on the DataCentre is capable of 16 bit transfers.
The Adaptec manual is very good, not just as a specific product manual but as a general introduction to early SCSI. The usual bit of software to use with Adaptec boards is Acorn's Superform which should be floating about somewhere.
Yep have been refering to the Adaptec and Xebec manuals both for the RM Nimbus MESS driver and for the SCSI<->IDE board, and agree the Adaptec manual is a pretty good refference.

Superform, will look again to see if I can find that.
Basically, what happens is that you send a Mode Select command to the controller informing it of the drive geometry, interleave, stepping speed, etc. and then you do a Format Entire Media sending in a defect list if there are any bad sectors on the front of the drive. Then you Verify, translate any bad sectors into their physical location on the drive and Format again with the updated defect list and repeat until you get a verify without any errors.
Yeah I think that's what the Nimbus Adaptec formatter does....that's one of the advantages of MESS, you can trace things like that and work out what they are sending. I'd have to at least accept the command and return a valid response, even if I don't actually do any formatting..... Verifying is esentially just a read, that's already done.

Humm I wonder if the Adaptec SCSI card in my test setup would cope with 256 byte sectors.....

Cheers.

Phill.

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Re: Beebs and SCSI Hard disks.....

Post by Prime » Fri Jan 07, 2011 6:51 pm

Just incase it was the right rom I've dumped it, after all it's a good idea to do that as EPROMS can go bad......

Anyway here's the rom from my Xebec card..
S1410.zip
Xebec S1410 rom
(3.17 KiB) Downloaded 165 times
Cheers.

Phill.

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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Mon Jan 10, 2011 11:27 pm

Great, I'll try that at some point.

I'm attaching a couple of disc images of hard drive formatters, including Superform. I can't remember where these came from. The files are dated February 2004 on my computer and I've long since forgotten their provenance, so all credit to whoever ought to be credited.
Hard.zip
(41.23 KiB) Downloaded 191 times
HForm.zip
(72.59 KiB) Downloaded 168 times
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Re: Beebs and SCSI Hard disks.....

Post by RobC » Tue Feb 08, 2011 8:51 pm

Hi all,

Inspired by this thread, I've just managed to get my Oak SCSI board talking to a 1GB Seagate Hawk drive (Model ST31230WC). I hooked it up to my RiscPC via a 80-pin to 50-pin adapter and issued the following commands via the SCSI_Op SWI:

Mode Select (to set it to 256 byte sectors)
Format Unit (to do the low level format)
Change definition (to set it to SCSI-1 mode)

I then removed the parity enable jumper, plugged it all in to my Master and fired up the STINIT routine from the disk BeebMaster provided. And lo and behold, it all worked :D

I'm not sure if all of this was necessary and I doubt that I've initialised the drive to the correct size but I'm just so pleased to see it working!

Cheers,

Rob

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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Thu Jan 30, 2014 3:15 am

Anyone tried a Syquest SQ5110C?

Someone just gave me one......... no disk, however ebay will fix that.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Thu Jan 30, 2014 10:35 pm

Is that the one with 88MB cartridges? I couldn't get it to work last time I tried, but that was in the pre-change-definition-revelation era, so it could be a possibility.
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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Fri Jan 31, 2014 8:20 am

BeebMaster wrote:Is that the one with 88MB cartridges? I couldn't get it to work last time I tried, but that was in the pre-change-definition-revelation era, so it could be a possibility.
That's the one. I don't have media for it and was hoping to confirm that it works with the Beeb before I order a couple of disks........
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Fri Jan 31, 2014 11:32 am

The 44MB (SQ555) one definitely works straight off without any trouble (although my website suggests it doesn't!)

Possibly I couldn't format it at that time, it maybe won't work with Superform which is really for MFM/RLL ST506 drives and controllers rather than SCSI ones. I think I subsequently used a Morley Electronics format or wrote my own utility.

I think at the same time I had an 88MB one which I couldn't get to work, and I subsequently got a 200MB one which wouldn't work either.

I'll have to get them back from storage and have another go. I've added it to the BeebMaster to-do list, item no 81.

I recall that there is a certain amount of backwards compatibility with these Syquest drives, so I think the 88MB drive will possibly work with 44MB cartridges.

I also tried Syquest EZ135 and EZ230 drives fairly recently, before they went in storage in August 2012, but I don't seem to have taken any pictures or recordings, so that's a bit of a shame, but I expect that means they didn't work either.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Fri Jan 31, 2014 12:15 pm

Prime wrote:Just incase it was the right rom I've dumped it, after all it's a good idea to do that as EPROMS can go bad......

Anyway here's the rom from my Xebec card..
S1410.zip
Cheers.

Phill.
I still haven't tried it yet! I'll have to find where my 2732s are, although my board has a 2732 in a 28-pin socket so possibly I could use a 27256 if I put the data in the right bit!

Was there a part number on the ROM? Mine - the standard version - is 104788 and according to the manual there were two revisions, a performance version 104792 (which apparently sacrified some disc space for a bit more interleave ??!!) and the one we really want which is 104793 and stores the geometry in cylinder 0 of the disc.
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Re: Beebs and SCSI Hard disks.....

Post by Prime » Fri Jan 31, 2014 1:28 pm

BeebMaster wrote: I still haven't tried it yet! I'll have to find where my 2732s are, although my board has a 2732 in a 28-pin socket so possibly I could use a 27256 if I put the data in the right bit!
Thats deffo possible, you could of course just fill the rom with repeating copies of the 2732, that way it would be sure to be in the right bit :)
Was there a part number on the ROM? Mine - the standard version - is 104788 and according to the manual there were two revisions, a performance version 104792 (which apparently sacrified some disc space for a bit more interleave ??!!) and the one we really want which is 104793 and stores the geometry in cylinder 0 of the disc.
Not sure, and I don't currently have the free space to drag the XW-40 out and look. I'll try and have a tidy up and see if it has a serial no.

Cheers.

Phill.

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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Fri Jan 31, 2014 1:43 pm

I had a look at the code but I couldn't see anything that conforms to the part numbers, although I don't understand Z80 code so it's probably beyond my decrypting powers.

I'm not sure how to tell which version is being used, you'd probably have to try one of the commands introduced in the later version and test for a bad command type response.
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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Fri Jan 31, 2014 10:03 pm

BeebMaster wrote:The 44MB (SQ555) one definitely works straight off without any trouble (although my website suggests it doesn't!)

Possibly I couldn't format it at that time, it maybe won't work with Superform which is really for MFM/RLL ST506 drives and controllers rather than SCSI ones. I think I subsequently used a Morley Electronics format or wrote my own utility.

I think at the same time I had an 88MB one which I couldn't get to work, and I subsequently got a 200MB one which wouldn't work either.

I'll have to get them back from storage and have another go. I've added it to the BeebMaster to-do list, item no 81.

I recall that there is a certain amount of backwards compatibility with these Syquest drives, so I think the 88MB drive will possibly work with 44MB cartridges.

I also tried Syquest EZ135 and EZ230 drives fairly recently, before they went in storage in August 2012, but I don't seem to have taken any pictures or recordings, so that's a bit of a shame, but I expect that means they didn't work either.
I'll buy both 44 and 88 media and add it to my list also.

My focus is on making a PC, and installed SCSI card, work in 'target' mode to appear like a 256 byte sector SCSI I drive to the Beeb. I'm still collecting parts for this project and will hopefully conduct some initial tests in late February.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Sat Feb 01, 2014 1:46 pm

I've been and retrieved my Syquest kit from storage this morning, so I'll have a go with the 88MB drive and report back.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Sat Feb 01, 2014 5:00 pm

It's all very promising...

The 88MB SQ5110 drive gave me a disc error 2 from ADFS with no cartridge in it, that means drive not ready, so it means ADFS is happily communicating with the drive. When I put in a selection of 88MB and 44MB I started to have problems with them spinning up and then clunking back to a stop again and then the lights flicking and some clicking noises coming from inside the drive.

On one occasion I did get ADFS to mount one of the 88MB cartridges, which reported an empty $ dir and ~42MB of free space with a good map, so I must have formatted that particular one some time in the past.

After that I couldn't get it to spin up properly, so I suspected a PSU issue. Trying to run it off a BBC B aux power output might not be sufficient since it needs 1.7A at 12V and 0.7A at 5V.

So I connected it up to PSU in the external case to the 200MB drive, but the same thing happened.

I couldn't get it to respond to an Enquiry command.

Next I tried the 200MB drive itself, with its own PSU, and a similar thing happened but eventually after about 2 minutes of it click.start.click.stop.clunking it spun up to speed with a 200MB cartridge and ADFS let me mount it. Broken dir and bad FS map, as expected, but examining the sectors with ADT's *DEX gave me some data, including phrases like "Apple-partition-map", "Apple-Scratch", "Apple-HFS" etc. so it must be formatted to some Apple type of format.

The 200MB drive responds to the Enquiry command and mode sense 0, 3 and 4.

I've put the 88MB drive and cartridges on the radiator for a couple of hours in case being in storage has given them a bit of a chill, and I'll have another go later.

The SCSI cable I am using between the drive and my Akhter host adapter has a SCSI terminator block plugged into it and has pin 34 cut. The 200MB drive already had the three terminating resistors plugged into it; the 88MB didn't but I've added some.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Sat Feb 01, 2014 9:51 pm

Warming it all up certainly helped, the cartridges will spin up now first time without any trouble. This 88MB drive is still a little bit erratic though, every now and again it will suddenly spin down and both lights come on.

The manual doesn't say what it means when both lights are on constantly when the drive isn't spinning.

Changing the disc doesn't bring it back to life, it requires a few minutes with everything powered off - drive, host adapter, Beeb, monitor, otherwise when it's switched back on, the two steady lights just come back on.

I've got two each of the 44MB and 88MB cartridges. One of each appear to be unformatted, all I can get out of them is disc error 3, and then the green light flashes, which may mean unformatted cartridge.

The other two are formatted to ADFS, the 44MB one has "Acorn ADFS formatted 43333KB" written on it by me, and it appears to read OK in ADFS.

The 88MB has about 42MB of ADFS free space on it, but gives bad sum and broken directory errors intermittently. Using mode sense tells me it is formatted to 512 byte sectors so that's why.

The drive is slow though, really slow, even slower than a laserdisc or a floppy disc. I don't understand why that is yet, unless it's connected to the fault which makes it power down randomly.
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Tue Feb 04, 2014 12:42 am

Mixed results really...

With the SQ5200 200MB drive, I can read/write and format a 44MB cartridge. It can be mode selected to 256 bytes per sector, and after the format, it reads correctly under ADFS.

The 88MB cartridge won't change to 256 bytes per sector, the mode select command fails, and although formatting works and data can be written to the disc, it can't be read back as I just get broken directory and bad sum errors.

The same thing happens with a 200MB cartridge, except that the mode select command doesn't give an error, but it still stays at 512 byte sectors.

I think there may be a problem with my SQ5110 88MB drive. It won't format either of my two 88MB cartridges, just fails with a disc error 3, which is media error. I can read the 44MB cartridge formatted in the 200MB drive, but I can't write to it because the SQ5110 doesn't allow writes to 44MB cartridges - I get disc error 7, which is write protected.

Apparently the SQ5110C was a later revision which did allow write access to 44MB cartridges.

Interestingly, the Enquiry command reports the product code as SQ5110 for one of my 88MB cartridges but SQ5110C for the other.

It won't accept a 200MB cartridge at all, it just spins down and then blinks 5 green, 3 red which means no servo.

Hopefully if yours is an SQ5110C you will be able to read and write 44MB cartridges, but I don't think 88MB will work as they don't appear to be able to format to 256 byte sectors.
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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Mon Feb 24, 2014 11:19 am

I've been playing around with replicating Beebmaster's success with changing a Seagate drive mode from SCSI-2 to SCSI-2, except I wanted to use DOS.

Here's a log of my effort including my eventual success! (hopefully).

http://www.vintage-computer.com/vcforum ... post315750
WISH LIST: Acornsoft C Compiler PDF manual, Anything 68008/68000 related, LVL Upgrade manual/ROMS, Watford Floppy Drive Selector, Commodore (CBM) PET ROM/S for CST Procyon IEEE-488 Interface", Beeb on a Eurocard systems

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Re: Beebs and SCSI Hard disks.....

Post by george.h » Tue Feb 25, 2014 2:28 pm

Hey Prime,

Good work - hope it works for you! One of these days I'll check what I did on my Seagate drive as I don't think I had to change SCSI mode on it (at least I can't remember doing it - or perhaps that is senility kicking in LOL).

My avatar pic BTW is the drive from a Netware 3.11 server which the drive now working on my Master was added to (many many MANY moons ago) before both (or rather all four - mirrored) were replaced with a RAID 5 array...... :wink:

Couldn't resist turning it into an ornamant - being a full height (or is it 3/4 height?) 3.5" drive and quite weighty, it also makes a good armament! :twisted:
Pic Caption: "One day son, this will all be yours..."

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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Mon Mar 03, 2014 11:08 am

Well it's been a long march, with a long way to go, however I now have:

1. Beeb with Watford SASI controller connected. :D

2. Watford also put 5V on pin 34 of the SASI connector, I decided to simply cut the PCB trace.

3. I have set my Seagate ST31200N to SCSI-1 (on a DOS PC with Bart's SCSITOOL).

4. I'm about to install Acorn ADFS (Ver 1.3 on a Model B?)

5. I have a Solidisk Issue 1 DFDC which I wlll remove and replace with an Issue 2 which I also have! 8)


Can someone point me to an archive/site of useful Winchester tools/utilities/routines etc?
WISH LIST: Acornsoft C Compiler PDF manual, Anything 68008/68000 related, LVL Upgrade manual/ROMS, Watford Floppy Drive Selector, Commodore (CBM) PET ROM/S for CST Procyon IEEE-488 Interface", Beeb on a Eurocard systems

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Re: Beebs and SCSI Hard disks.....

Post by jgharston » Mon Mar 03, 2014 11:57 am

IBM portable PC wrote:Can someone point me to an archive/site of useful Winchester tools/utilities/routines etc?
Fairly crappy disk sector editor:
http://mdfs.net/Info/Comp/BBC/IDE/ADFS/Apps
Broken disk map repairer:
http://mdfs.net/Apps/Filing/Repairing
Function to interface to disk sector access routine:
http://beebwiki.mdfs.net/index.php/OSWORD_%2672#Coding

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.25
(C) Copyright J.G.Harston 1989,2005-2015
>_

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Re: Beebs and SCSI Hard disks.....

Post by IBM portable PC » Thu Mar 13, 2014 7:07 am

I've moved to the next stepping stone with my Watford Winchester controller after setting the SCSI drive (A Seagate ST31250N) to SCSI-1 using Bart's SCSITOOL:

Below you can see my setup:
- A protruding Seagate SCSI HDD (with Parity Off, Termination Enabled, Termpower to the drive and the bus and it's set as Drive 0)
- The drives external housing showing that the drive is selected i.e. the glowing red LED.
- An Ancot SCSI analyzer showing that Termpower is detected and good, and that a SCSI select command has been issued.

However, the drive appears to NOT be responding!

When I initially power up, the lights in the street dim..... only kidding! ;) It actually displays:

BBC Computer
Acorn ADFS

and then promptly sits there forever, however it's trying to talk to the drive as the analyzers log contains:
00001: RESET start
00003: RESET end
00003: Bus free
00004: RESET start
00005: RESET end
00005: Bus free
00006: Select /01 (0)

To get to a prompt I hit:
CTRL-F-BREAK
(Thanks to Beebmaster's SCSI tutorial on his site for this tip! - Not sure exactly what it does [yet] however........)

This presents:

BASIC
>

And I can type:
>*MOUNT 0

To which it simply does nothing once more whilst the analyzers log contains this sole entry:
00001: Select /01 (0)

My Watford controller has had it's termination resistors removed by a previous owner (why?) and I'm currently waiting on a pass-through 50 pin header type terminator from eBay and so I'll have to call it a day until there as I obviously want to ensure my problem is not 'simply' termination (see my Watford controller here: viewtopic.php?f=3&t=7098 )

I'm also using premium SCSI cables from Granite.

All thoughts are welcome........
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WISH LIST: Acornsoft C Compiler PDF manual, Anything 68008/68000 related, LVL Upgrade manual/ROMS, Watford Floppy Drive Selector, Commodore (CBM) PET ROM/S for CST Procyon IEEE-488 Interface", Beeb on a Eurocard systems

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Re: Beebs and SCSI Hard disks.....

Post by george.h » Thu Mar 13, 2014 2:02 pm

Hi,

I think you've missed out one important step. This is shown as item 2 below from one of my older posts from when I got my Seagate Hawk 1GB drive to work.
I've came across some of my drunken spider notes from back then and the two main changes I made to get it working were :

1. Use Mode Select to change the block length from 000200h to 000100h, i.e. change the sector size from 512 to 256 bytes. I then had to initiate a low level format.

2. This is the one that really had me flumoxed for a while. At first after a reset (power on or hard BREAK) the drive would stubbornly sit there with a Check Condition status and ignore everything until I issued a Request Sense command. Since ADFS doesn't do this, I had to do this manually every time. After that it would work and ADFS could talk to it, even through at that point I hadn't figured out formatting it under ADFS. To fix this I had to change a bit on page 0 (Unit Attention Parameters) of the Mode Sense Pages. Basically I had to change bit 4 in byte 2 from 0 to 1. This controlled the drives Unit Attention behaviour so that the drive no longer sits there in Check Condition state waiting for a Request Sense command after reset.
Let me know if this helps.....
George
:wink:
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Re: Beebs and SCSI Hard disks.....

Post by BeebMaster » Thu Mar 13, 2014 11:50 pm

The mode select to change the sector size to 256 bytes is important for formatting and using the drive as an ADFS disc, but it isn't required in order to get ADFS to communicate with the drive.

ADFS will happily co-exist with drives of sector sizes other than 256 bytes, but you can't put an ADFS format onto such a disc and expect it to work correctly as all disc reads done by ADFS will return too much data and corrupt the ADFS workspace.

Proof here:

http://www.beebmaster.co.uk/SCSI512.html

What is needed, however, is for the operating definition of the drive to be changed to SCSI-1 and then it will be recognised by ADFS. It isn't possible to do this on a Beeb, I do this using an Archimedes with a SCSI podule.

An alternative is to alter the check condition/unit attention settings of the drive; I've done some work on that method more recently but I can't just remember the conclusions I came to; I think from memory it is possible to change the unit attention setting and then do the change definition command using a BBC.
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Re: Beebs and SCSI Hard disks.....

Post by george.h » Fri Mar 14, 2014 2:20 pm

What is needed, however, is for the operating definition of the drive to be changed to SCSI-1 and then it will be recognised by ADFS. It isn't possible to do this on a Beeb, I do this using an Archimedes with a SCSI podule.
I must get round to checking if I did this on mine as I don't remember having to. Plus not having an Archie to hand (one never does at such times :lol: ), and not having twigged about OSWORD &72, probably because I was doing everyting from DFS (don't ask me why and I'll not give you some clap trap explanation for my mental aberation :lol: ) I did it all by direct bit twiddling of the SCSI interface.
An alternative is to alter the check condition/unit attention settings of the drive
Now this I found to be essential as the factory default of my drive was for power-on reset (of the drive itself) to generate an automatic Check Condition status. Once that happened it steadfastly ignored EVERYTHING I sent to it until I'd sent Request Sense. Then it sat up an took notice (rather like the one in my avatar :) )
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