! ! 3 1/2" PC Drive/s on a beeb ! !

[sydney]

I think putting the cable in the wrong way round will cause the led to be constantly lit. Perhaps you have shorted one of the wires when you removed the pc twist.

[rharper]

Thx for posting that link.. might find a few uses for one of those.... gotta be worth a fiver with free delivery. even if only for bench testing purposes.

They go bang with more frequency than Beebmaster's LV ROM Drives! Stay well clear of those china cheapie PSUs. They also run VERY hot, when they do run at all!

I only just saw this, and that item is still available. It's something I could really make use of, I've never seen a mains PSU ending in a hard drive connector like that before. I'd probably have bought a couple of dozen of them if it wasn't for this warning. Anybody know of a reliable substitute?

I have used a good number of these cheap psu's over the last few years, mostly for powering internal 3.5" floppy drives as external drives on beebs and electrons.
You can of course chop off the molex connector and solder on connectors for other equipment.
About 4 years ago they did indeed get very hot and if left on for a few hours might go bang! I tended to use them just for an hour or 2.
I have removed the top and drilled holes for ventilation to improve the dissipation of the heat.
However, the ones I have bought over the last 2 years look the same but are completely different.
The originals have a board completely packed with components, many large caps, that took up about 80% of the inner volume so only 20% air for taking up the heat!
The recent ones have a sparsely populated board with about 95% inner volume air. They get warm but no more so than any other psu. I have left them on 16h and they are no warmer after 16h than after 2h.
It is possible that I have just been lucky with my recent purchases.
I got the last lot here http://www.ebay.co.uk/itm/HDD-POWER-SUP ... OC:GB:3160
Ray

[1024MAK]

There are a number of problems with the cheap PSUs:-

• Safety issues - some do not meet UK or European standards for the clearance/creapage gap(s) between the mains side circuitry and the low voltage output circuitry on the circuit board, without opening and destroying the transformer, it is very hard to tell if there is a proper isolation barrier between the primary and secondary windings, any wires inside the PSU should be restrained to ensure if one becomes loose, it cannot move and touch another component or conductor (a mains wire touching the low voltage section or a low voltage output wire touching the mains circuitry) but often the wires are loose,
• The bare minimum of components are used, this means NO interference suppression inductors or capacitors on the mains input side, NO mains surge protection and only one filter capacitor for each output voltage rail (a good PSU will have a capacitor/inductor/capacitor filter),
• The "regulation" circuit is often a basic design and may not give good regulation. Note also, a lot of switch mode PSUs only regulate one output rail.
• The components are not high quality, and the values used for the capacitors may be somewhat random. In some (different) inexpensive PSUs I got to see what they were like, the higher current ones (according to the label) had smaller value capacitors than the lower current rating units!

I know it is difficult to get decent combined 5V and 12V power supplies. But I strongly suggest you pay the extra and get a good quality PSU from a well know quality supplier in your country if you can.

Also, some of the more modern 3.5" drives often only use the +5V line (they don't need a +12V supply).

Mark

[MartinB]

Genuine APD PSU's are good quality in my experience but are necessarily more expensive. There are lots of different permutations of voltage and current - have a scan on ebay for something like 'APD 5v 12v' to see the options and prices. I've actually run Beebs off the DA-45C01 (5v/4A & 12v/2A and I added a small -12v regulator) but they are harder to find and can command significant money. I got one from a car boot for 50p but I will shortly have another because earlier on this evening, I acquired one through an ebay Best Offer of £8.50 inclusive... (I obviously didn't want to post this until I'd snaffled it... ) You obviously don't need the capacity of the 45C01 for disc drives, many of the lower spec APD devices would be fine.

[beebdidi]

Hi,
Found this 'old' article :
http://amigadrive.blogspot.fr/2013/11/h ... loppy.html
It might be possible to do the same with BBC B or Master ?

Cheers

[MrEe]

Hi All,

My first real post on the forums -

I'm probably resurrecting an old thread here but I had to share this with someone who would appreciate the achievement (for me at least). My pet cat has more interest in this than my wife..

Anyway, down to business: A bit of background: I've been tinkering around my old Cumana dual 80/40 track 5.25" floppy drives for a while and was really pleased with them until somehow - and don't ask me how - drive zero magically died. In another sad and annoying parallel my single Cumana 5.25" FDD died too (a few months earlier) - must be Canadian air. Anyway, I have one functioning 5.25" drive left. After reading all the excellent information about 3.5" drives on the forums I decided to rig up dual 3.5" FDD's with the intent of placing them in the Cumana housing as I had previously bought another step-up transformer to run the beastie and I'll be damned if I'm going to let it go to waste.

The two FDD drives that I had knocking around were Alps Electic Co. Ltd, DF354H022F's taken from two old IBM PC Thinkcentre's. These work a treat with the BBC Model B. Having taken out the twist from the drive cable and trying each drive individually, they both registered as drive 1 and work flawlessly (so far, touch's head). So that was one drive. THEN I decided that I needed a second drive - primarily for Beebug C. As others have quite rightly pointed out in the forum thread, that the PC drives are set for DS1. Next order of business was to set one of the two drives to DS0. The Alps drives - thankfully - are well designed in this respect and the DS1/DS0 extremely easy to access via a small window in the casing thereby exposing the board. One of the connectors (DS0) is an exposed copper link that looks like a penny with a black horizontal line going through it. This made me wonder as joining the two halves had to make the connection active (smart design). Conversely, exposing the DS1 connection would unlink the connection. So after desoldering (or should I say "desoddering" in N. America? ) DS1 and soldering DS0 I plugged in the FDD cable (with twist taken out) and fingers crossed fired-up the Beeb entered *Disk/*.0 then */1 - - bingo! - both drives recognised correctly . Using some really expensive DSDD drives, did the formatting and verification and worked flawlessly. I'm so happy! Now this piqued my interest even more. Everything that I read about 1.44 HD floppies said that would work (maybe) or not reliably. I decided to take the pepsi challenge on this one too. So I dug out some old 1.44" floppies and covered one of the hold with black electrical tape which just happened to be pasted to my desk (as I had installed Datacentre a few days before and used electrical tape on some connectors - that's another story - so covering the second hole on the floppy, inserted the disk and ran a format/verify cycle and it worked(!) So now I'm pretty happy as I can use the 1.44" as temporary mediums (all risks acknowledged) and don't have to sell a kidney to buy another set of DSDD (which incidentally, I threw an entire black bin-liner full of into a skip about 10 years ago - still kicking myself over that one).

Next thing (and the original plan) was to put the drives in to the old Cumana housing using some 5.25"->3.5" drive cradles in place of the drives; but I decided instead to make a dual rig out of two old CD-Rom shells using the drive housing I purchased earlier - added some feet to the entire setup and it works a treat!

So to sum it up - yes, it's really easy to get the 3.5" drives up and running and yes 1.44" HD's can be used (with caution - YMMV). My total cost for the entire setup was $14.00 to get the 5.25"/3.5" FDD housing (Amazon sale). The "feet" were the lids of old mouthwash bottles hot-glued in place. Not the best looking but it works

Here's a piccy:-

Apologies for the wall of text, but I JUST HAD to tell somebody. Hopefully, this will/can help somebody too!

Oh and just to say thanks to everyone who posted some great information which helped a lot - awesome community!

[danielj]

Well done! it's really satisfying to get something to work

[Lardo Boffin]

At the risk of going off topic I see you are using Beebug C. I have recently got started using it and managed to get it running in ADFS on my CF card HDD connected to my datacentre - this way it compiles faster than from floppy.
I also want to use a co-processor to further speed it up but switching from a text editor to C run from the co-proc causes all sorts of issues. Have you tried this and got it working MrEe?
We don’t have a cat but it is still more interested in this stuff than my wife...

[leenew]

Nice one

Lee.

[flaxcottage]

Love those orange feet!

[MrEe]

At the risk of going off topic I see you are using Beebug C. I have recently got started using it and managed to get it running in ADFS on my CF card HDD connected to my datacentre - this way it compiles faster than from floppy.
I also want to use a co-processor to further speed it up but switching from a text editor to C run from the co-proc causes all sorts of issues. Have you tried this and got it working MrEe?
We don’t have a cat but it is still more interested in this stuff than my wife...

It's funny that you should mention Beebug-C setup; That's my next project (apart from setting up the GoTek drive). I'm just waiting on male pin-headers to arrive and then setup my co-processor. I'll let you know if I make any headway on this. However, I have Beebug-C working on FDD but it is slow (but the nostalgia is part of the fun). My only problem at the moment is, ironically, that I run out of disc space when linking my code - Acornsoft's ISO Pascal was way better at handling this. Using Wordwise-Plus to edit C code in mode 7 is awkward to say the least - curly braces - "{" translates to "1/4" and " } " translates to "3/4" lol. I'll give Acornsoft's View a try! Incidentally, are you using a Master or BBC B with Datacentre? I didn't have much luck with the CF card on the Beeb (although I must admit I didn't spend too much time with it - lack of ADFS etc.)

[Lardo Boffin]

I tried the data centre in a model B to start with but eventually moved it to a Master. Being able to edit in mode 0 (mode 128 I think) with a full load of RAM is a major bonus. Plus ADFS and no wierd crashes or messages. Definitely recommended!
The problem I found was that if you write in an editor and then switch to co proc C (*CSP) it tramples on work spaces and C does’nt run. I had to switch off and on again each time. What is required is a text editor that actually runs in C. My misadventures can be found here - viewtopic.php?f=3&t=15201&hilit=Beebug

[MrEe]

I tried the data centre in a model B to start with but eventually moved it to a Master. Being able to edit in mode 0 (mode 128 I think) with a full load of RAM is a major bonus. Plus ADFS and no wierd crashes or messages. Definitely recommended!
The problem I found was that if you write in an editor and then switch to co proc C (*CSP) it tramples on work spaces and C does’nt run. I had to switch off and on again each time. What is required is a text editor that actually runs in C. My misadventures can be found here - viewtopic.php?f=3&t=15201&hilit=Beebug

Reading your linked thread about a month ago made me order the GoTek drive! (wonderful piece of kit BTW); I'm definitely going to have to check out a BBC Master. I empathise with the lack of in-built editor in C. Acornsoft Pascal is great in that respect, as it contains the in-built editor - really nice programming with it. Since my last reply, I got View running with Beebug-C and it seems quite good - you can *C into to compiler and *Word back to the editor with ease, plus I can code in Mode 3 at least.

[jugganaut]

Sorry to resurrect an old thread but I'm giving this a try with an old PC FDD I have lying around. I've made a 5v supply using an old phone charger, a FDD power plug cut off of a broken PC PSU and some chocolate block connector. I'm just trying to adapt an old FDD ribbon cable to work with it. Originally both ends had the type of plug with a pin missing so I cut one end off, added the twist described below to get drive 0 and bought some new 34 pin connectors off of eBay for a couple of quid. The issue is, these connectors have the bump on them so they can only be plugged in one way. This is fine as my AP3 has the corresponding cutout, but what I don't know is which end of the AP3 connector is pin 1. I've opened the case on it and can't see any markings on the PCB. Can anyone advise please?

Thanks in advance.

[MartinB]

Presumably you’re talking Elk and this style of AP3?

Assuming yes, Pin 1 is nearest the outer edge of the cartridge module, so under the ‘ACP’ of the yellow label on mine in the photo. On yours, you should just be able to make out a small arrow (triangle) moulded into the connector plastic which points to Pin 1.

[jugganaut]

That is the one and I can see the arrow now you've pointed it out, but didn't before!

Thanks for your help.

[mxmy]

Hello there (first post)!

I recently acquired a couple of beebs: a Model B and a Master.
I've fixed up the PSU for the Model B and I'm trying to get my floppy drives working with it with only limited success.

I started with the 2x TEAC 5.25" drives that came with the unit. I stripped them down, lubricated the rails and cleaned the heads. They both had a metal cover on the heads that were attached using double-sided sticky tape and foam, but the foam has thoroughly turned to black goo. For now I have left these covers off and cleaned up the goo with isopropyl.

Of these two drives, one seems to work okay, but makes horrible high-piched squeaking for about half of the head's travel. The other drive appears to play nicer, but actually cannot seem to read, write, format, verify or anything. I also have a stack of floppies that came with the beebs and none of them seem to work. The only discs that I got to work with them were 96TPI DSDD 3M New-Old-Stock Disks that I already had (had to unwrap a fresh pack which made me want to cry).

With one mostly working disk drive I tried a handful of 3.5" drives and I'm having an awful lot of trouble with them. I'm using an untwisted floppy cable and have tried drives that are hardware assigned to either 0 or 1. My floppy controller is a WD1770 and I've tried using Acorn ADFS and Watford DDFS 1.54T.

My 3.5" drives light up and seem to respond to the floppy controller signals, but if I try *FORM40 / *FORM80 / *VERIFY using DSDD disks they all fail.
I've tried *FX255,207,0 with a soft reset, but I'm still getting problems.

I'm absolutely at my wits end. Please kind internet people, help me understand what I'm doing wrong :'(

[flaxcottage]

Some PC drives do not work with Beebs unfortunately. If you have one of those it will be hard luck.

In a cable without a twist the PC drive is usually drive 1. Try *FORM80 1/ *FORM80 3 and see if they work. *VERIFY 1 / *VERIFY 3 will check it. The 3.5" drive will not have a 40/80T switching capability. The command *DRIVE 1 40 may help and switch the software to double step the heads giving the equivalent of 40 tracks but why waste 50% of the disc space?

[mxmy]

Some PC drives do not work with Beebs unfortunately. If you have one of those it will be hard luck.

In a cable without a twist the PC drive is usually drive 1. Try *FORM80 1/ *FORM80 3 and see if they work. *VERIFY 1 / *VERIFY 3 will check it. The 3.5" drive will not have a 40/80T switching capability. The command *DRIVE 1 40 may help and switch the software to double step the heads giving the equivalent of 40 tracks but why waste 50% of the disc space?

Thanks for replying John!

I've tried multiple different types of 3.5" drives and none of them are responding correctly. Some of these are set to drive select 1, but several have been modified to respond to DS0. One of the drives is ancient and is a single-side DD drive, but most of them are more modern drives (Mitsumi D359T6 , Sony MPF920 and such). I haven't tried *DRIVE 1 40 yet. Will give that a go.

I'm powering them from the PSU, which should be able to supply the 960ma @ 5V, but could this perhaps be the cause of the problem?
I've also installed DIP switches on the keyboard PCB, which does indeed affect the settings, but does not yield better results with the floppy drives.
The other thing that could possibly be wrong is the WD1770 floppy controller? Don't want to have to spend money to troubleshoot if I don't have to, but if the floppy controller is failing I'll need to get a new one.

When formatting the output is essentially:

Code: Select all

00?? 01?? 02?? 03?? 

Etc.

[flaxcottage]

The drives I use most are Mitsumi D359M3D. These work every time although they are set to be drive 1 and need a cable with a twist to be drive 0.

One difference between the T6 and M3D appears to be the RDY signal from the drive. The T6 does not provide one. Is a RDY signal needed on a Beeb? I don't know, sorry. There is a mod on the internet to provide a RDY signal for a CPC464 computer. Maybe that could help?

[mxmy]

The drives I use most are Mitsumi D359M3D. These work every time although they are set to be drive 1 and need a cable with a twist to be drive 0.

One difference between the T6 and M3D appears to be the RDY signal from the drive. The T6 does not provide one. Is a RDY signal needed on a Beeb? I don't know, sorry. There is a mod on the internet to provide a RDY signal for a CPC464 computer. Maybe that could help?

Ah fantastic, I'll test this! I know you can mod a drive to have 'ready' always set (can't remember off the top of my head if it's active high or low), which I've done previously on another 80's computer by connecting two of the pins on the floppy PCB. Will obtain a Mitsumi D359M3D, which should rule out weather it's the drives or something further down the chain. This is super helpful thank you! If it does work, I'll mod my other Mitsumi drive and see if that works correctly to solve the issue and post here again. Whilst I'm working on it there I'll see what options there are on the PCB for converting the D359M3D to respond as drive 0.

[mxmy]

So fantastic update: I have 3.5" drives working, as well as the 5.25" drive which I had though inoperable!
The solution was so simple I almost hit my head on the workbench: Tarnished pins on the floppy connector...

A bit of isopropyl and suddenly my woes were gone!

As I have a Mitsumi D359M3D on the way now anyway, I'll take a peek inside and see if there's an easy fix to change it to respond as drives 0&2 instead of 1&3. Also, as it turns out, the BBC Micro and Master do not make use of the READY or DISK CHANGE pins, so no modification to the drives is required there.

[Arkas]

It would be nice If there was a complete instruction for this. I'd love to add PC drives to the Beeb, I have 6 PC drives here that are old but work fine.

[flaxcottage]

One way of getting 3.5" and 5.25" drives working as drives 0 or 1 is here: http://www.flaxcottage.com/Projects/DiscDuck.pdf

I needed a system that would allow me to set up a versatile disc drive for archiving purposes. It can handle any disk drives that would work with the BBC, converting two single drives into a double drive; either drive can be set as drive 0 or drive 1.

[Arkas]

Thanks!

[SkaterMark]

Anyone know of any good cases to put the external PC 3.5” drive into?

[Rasp]

Years ago I used an old 5.25" USB DVD drive and put a 5.25 to 3.5 converter in to hold the floppy.

The picture is not the one I used but very similar.

[dankcomputing]

If you can find a Nakamichi MB-5 automotive CD changer, it's essentially the same mechanism as their SCSI CD changer but with different electronics. Since they're obsolete and not considered a "RETRO VINTAGE COMPUTER PART" they're often cheaper than any kind of computer-based 5.25 drive case, especially online.

The case can easily accommodate any 5.25 drive and is made of thin sheet metal, so it's not difficult to add whatever ports you want to the back plate.

[Bitstik]

So fantastic update: I have 3.5" drives working, as well as the 5.25" drive which I had though inoperable!
The solution was so simple I almost hit my head on the workbench: Tarnished pins on the floppy connector...

A bit of isopropyl and suddenly my woes were gone!

As I have a Mitsumi D359M3D on the way now anyway, I'll take a peek inside and see if there's an easy fix to change it to respond as drives 0&2 instead of 1&3. Also, as it turns out, the BBC Micro and Master do not make use of the READY or DISK CHANGE pins, so no modification to the drives is required there.

Genius- that’s been the problem I’ve been having. Now fixed many thanks to you! I’d tried 5 different drives!
One thing to note - most drives- if they don’t have jumpers, have solder bridges to make/break to choose drive 0 or drive 1. My alps drives are accessible from the outside case but the Samsung needs the cases taking off.