Ibm Pc Xt 5160 - UK Vintage Radio Repair and Restoration Discussion Forum

Dave Moll · 13th May 2007, 10:07 pm

Now that I have suspended my activities with the IBM PC AT 5170, I am turning my attention to the XT 5160 which I have had for some years.

Before I acquired it it had a problem with its full-height floppy disc drive such that it was unable to read data anything approaching reliably, so at the time I removed the offending article and replaced it with a (not entirely appropriate-looking) half-height drive and a blanking plate, which worked fine at the time.

After having sat unused for some time, I powered this machine up recently, only to find that it is no longer willing to communicate with the floppy drive (raising an error "601" on startup). I have tried other drives, with exactly the same result - so it appears to be a problem with the floppy disc controller (on an ISA card).

Does anyone have any suggestions how I might proceed?

Paul Stenning · 13th May 2007, 10:10 pm

I assume you have tried unplugging the card and leads, making sure any socketed chips are pressed fully home, hoovering out some of the dust, then reassembling and trying again?

Does it have a BIOS? If so, perhaps it has suffered amnesia due to a flat battery and forgotten what type of floppy drive it has? If it has though, I don't know how you would boot from the setup/diags disk to sort it out.....

paulsherwin · 13th May 2007, 10:17 pm

Check the moving parts of the FDD haven't seized with time.

Paul

Dave Moll · 13th May 2007, 10:25 pm

All leads have been pulled off, re-inserted and waggled to ensure no intervening oxide layers. There are no socketed chips on that particular board - and the dust level inside this machine appears to be somewhat lower than in the rest of my house

I don't think the XT has either a BIOS or a battery - though I stand to be corrected.

Howard81 · 15th May 2007, 5:18 pm

XT's don't have a BIOS, everything is controlled by a block of DIP switches on the motherboard. Make sure that they are set correctly as per the following:

http://www.howard81.co.uk/upload/vcf/xt/xtdips.gif

If that doesn't work, remove ALL of the cards except for the floppy controller and the display adaptor and try again.

Is the card a genuine IBM one, or aftermarket? If IBM, it should look like this:

http://www.howard81.co.uk/upload/vcf...controller.JPG

You could also try swapping the power connector for the other one (130W XT PSU's had 2 power leads, clone ones often had 4). Finally try another floppy cable.

The only battery you would ever find in an XT is for a third-party RTC.

Dave Moll · 15th May 2007, 5:49 pm

Thank you for:

a) confirming what I believed to be the case about the lack of any sort of BIOS or battery in the XT.

b) the table of DIP switch settings - a piece of information which I didn't have.

The existing FDC is identical to the one pictured above - including the enormous D connector.

I will try swapping the power connectors (original power supply with only two of them) between the floppy and hard drives and see whether the fault migrates to the hard drive.

Unfortunately, I don't have a spare of this style of floppy cable. I have loads of spares, but they all have the connector for a controller board with two rows of pins - though the B drive connector is in parallel with the controller connector (cable too short between this and the A connector for the internal drive but could try this with the spare to test).

I will try each of these and report back. I will also confirm the settings of the DIP switches, but can't imagine that these have changed since it was previously working!

Dave Moll · 15th May 2007, 7:22 pm

Quote:

Originally Posted by Dave Moll

I will try swapping the power connectors ... between the floppy and hard drives and see whether the fault migrates to the hard drive.

No, the fault was totally unmoved.

Quote:

I don't have a spare of this style of floppy cable ... though the B drive connector is in parallel with the controller connector (cable too short between this and the A connector for the internal drive but could try this with the spare to test).

Likewise, no change (using the B drive connector to connect to the FDC).

The DIP switch settings (as expected) are:

0 - normal operation
1 - no 8087
00 - 640K
00 - monochrome
11 - 1 diskette drive

Howard81 · 15th May 2007, 8:18 pm

Hmm...

Maybe try disconnecting the hard drive from the power (you mentioned it was unreliable) as it could be causing weird voltages. I had that happen on a dead ST-412 before.

I know you mentioned that you tried other drives, but have you tried your 'faulty' drive in a known working machine?

Try removing all the cards except the floppy controller and display adapter. It probably won't change anything, but at least you can eliminate a rogue card

You could also try moving the floppy controller to another slot (any except the 8th slot next to the PSU will work).

Unfortunately I don't have any spare floppy controller cards nor cables, but they do turn up on eBay occasionally. I do have two XT's and two 5150s, but I don't want to part them out

Dave Moll · 15th May 2007, 10:58 pm

Quote:

Originally Posted by Howard81

Maybe try disconnecting the hard drive from the power (you mentioned it was unreliable) as it could be causing weird voltages. I had that happen on a dead ST-412 before.

I have had no problems with the hard drive. Are you thinking of my mention of the original full-height floppy drive which I had to replace.

I have now made arrangements with another forum member to acquire a replacement FDC, so I think I will now await its arrival before making any other configuration changes.

I will report back how things go with the replacement FDC.

Howard81 · 15th May 2007, 11:11 pm

My mistake about the hard drive / floppy confusion

It would be interesting to see if the new cable does indeed solve the problem

Also, out of interest, IBM actually shipped later model XT's with half-height floppy drives as standard, so it is perfectly in keeping. Full height floppy drives seem somewhat unreliable, I have 6 of them - all dead!

OldBoffin · 16th May 2007, 4:02 pm

Hi folks,
All the XT machines I've ever sold had a BIOS - I sold quite a lot at half the IBM prices! I ran an IT Training and Sales Centre for some 6 years in the 1980s just in the boom time! Selling BBCs,Acorns,Torch and IBM Clones, together with networks etc. We preferred the Phoenix Bios but some machines/software needed AMI or Award Bios chips.
I've just got some of my old reference books down off the top shelf and confirm that a 601 error refers to the FDC.
I scraped 2 XTs and an AT last year but still have spare PSU, and some cards for them - available for donations to my Macmillan Cancer fund appeal.
Also "IBM PC troubleshooting &Repair Guide" by RC Brenner for sale similarly.
I'll help where I can but memory is getting a bit rusty after 50 years in computers! I patented the Optical Encoder in 1954 when working on a Hollerith Punched Card computer!
Regards,
OldBoffin

Dave Moll · 16th May 2007, 5:20 pm

Quote:

Originally Posted by OldBoffin

All the XT machines I've ever sold had a BIOS

Sorry, I realise that I was using the wrong term. What I was referring to is the settings held in battery-backed memory.

Dave Moll · 18th May 2007, 5:41 pm

Thanks to "Oldboffin" I now have a replacement FDC board - which has solved the problem. I am now able to access floppy discs again.

The computer is now back in working order, so the thread has served its purpose, unless there is any further discussion others wish to raise on this machine.

13th May 2007, 10:07 pm	#1
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Ibm Pc Xt 5160 Now that I have suspended my activities with the IBM PC AT 5170, I am turning my attention to the XT 5160 which I have had for some years. Before I acquired it it had a problem with its full-height floppy disc drive such that it was unable to read data anything approaching reliably, so at the time I removed the offending article and replaced it with a (not entirely appropriate-looking) half-height drive and a blanking plate, which worked fine at the time. After having sat unused for some time, I powered this machine up recently, only to find that it is no longer willing to communicate with the floppy drive (raising an error "601" on startup). I have tried other drives, with exactly the same result - so it appears to be a problem with the floppy disc controller (on an ISA card). Does anyone have any suggestions how I might proceed? __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

13th May 2007, 10:10 pm	#2
Paul Stenning Administrator Join Date: Dec 2002 Location: Cardiff Posts: 9,071	Re: Ibm Pc Xt 5160 I assume you have tried unplugging the card and leads, making sure any socketed chips are pressed fully home, hoovering out some of the dust, then reassembling and trying again? Does it have a BIOS? If so, perhaps it has suffered amnesia due to a flat battery and forgotten what type of floppy drive it has? If it has though, I don't know how you would boot from the setup/diags disk to sort it out..... __________________ Paul Stenning Forum Admin/Owner and BVWS Webmaster

13th May 2007, 10:17 pm	#3
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: Ibm Pc Xt 5160 Check the moving parts of the FDD haven't seized with time. Paul

13th May 2007, 10:25 pm	#4
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Ibm Pc Xt 5160 All leads have been pulled off, re-inserted and waggled to ensure no intervening oxide layers. There are no socketed chips on that particular board - and the dust level inside this machine appears to be somewhat lower than in the rest of my house I don't think the XT has either a BIOS or a battery - though I stand to be corrected. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

15th May 2007, 5:18 pm	#5
Howard81 Triode Join Date: Oct 2005 Location: London, UK. Posts: 11	Re: Ibm Pc Xt 5160 XT's don't have a BIOS, everything is controlled by a block of DIP switches on the motherboard. Make sure that they are set correctly as per the following: http://www.howard81.co.uk/upload/vcf/xt/xtdips.gif If that doesn't work, remove ALL of the cards except for the floppy controller and the display adaptor and try again. Is the card a genuine IBM one, or aftermarket? If IBM, it should look like this: http://www.howard81.co.uk/upload/vcf...controller.JPG You could also try swapping the power connector for the other one (130W XT PSU's had 2 power leads, clone ones often had 4). Finally try another floppy cable. The only battery you would ever find in an XT is for a third-party RTC.

15th May 2007, 5:49 pm	#6
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Ibm Pc Xt 5160 Thank you for: a) confirming what I believed to be the case about the lack of any sort of BIOS or battery in the XT. b) the table of DIP switch settings - a piece of information which I didn't have. The existing FDC is identical to the one pictured above - including the enormous D connector. I will try swapping the power connectors (original power supply with only two of them) between the floppy and hard drives and see whether the fault migrates to the hard drive. Unfortunately, I don't have a spare of this style of floppy cable. I have loads of spares, but they all have the connector for a controller board with two rows of pins - though the B drive connector is in parallel with the controller connector (cable too short between this and the A connector for the internal drive but could try this with the spare to test). I will try each of these and report back. I will also confirm the settings of the DIP switches, but can't imagine that these have changed since it was previously working! __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

15th May 2007, 8:18 pm	#8
Howard81 Triode Join Date: Oct 2005 Location: London, UK. Posts: 11	Re: Ibm Pc Xt 5160 Hmm... Maybe try disconnecting the hard drive from the power (you mentioned it was unreliable) as it could be causing weird voltages. I had that happen on a dead ST-412 before. I know you mentioned that you tried other drives, but have you tried your 'faulty' drive in a known working machine? Try removing all the cards except the floppy controller and display adapter. It probably won't change anything, but at least you can eliminate a rogue card You could also try moving the floppy controller to another slot (any except the 8th slot next to the PSU will work). Unfortunately I don't have any spare floppy controller cards nor cables, but they do turn up on eBay occasionally. I do have two XT's and two 5150s, but I don't want to part them out

15th May 2007, 11:11 pm	#10
Howard81 Triode Join Date: Oct 2005 Location: London, UK. Posts: 11	Re: Ibm Pc Xt 5160 My mistake about the hard drive / floppy confusion It would be interesting to see if the new cable does indeed solve the problem Also, out of interest, IBM actually shipped later model XT's with half-height floppy drives as standard, so it is perfectly in keeping. Full height floppy drives seem somewhat unreliable, I have 6 of them - all dead!

16th May 2007, 4:02 pm	#11
OldBoffin Retired Dormant Member Join Date: Jan 2007 Location: Rugeley, Staffordshire, UK. Posts: 54	Re: Ibm Pc Xt 5160 Hi folks, All the XT machines I've ever sold had a BIOS - I sold quite a lot at half the IBM prices! I ran an IT Training and Sales Centre for some 6 years in the 1980s just in the boom time! Selling BBCs,Acorns,Torch and IBM Clones, together with networks etc. We preferred the Phoenix Bios but some machines/software needed AMI or Award Bios chips. I've just got some of my old reference books down off the top shelf and confirm that a 601 error refers to the FDC. I scraped 2 XTs and an AT last year but still have spare PSU, and some cards for them - available for donations to my Macmillan Cancer fund appeal. Also "IBM PC troubleshooting &Repair Guide" by RC Brenner for sale similarly. I'll help where I can but memory is getting a bit rusty after 50 years in computers! I patented the Optical Encoder in 1954 when working on a Hollerith Punched Card computer! Regards, OldBoffin

18th May 2007, 5:41 pm	#13
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,127	Re: Ibm Pc Xt 5160 Thanks to "Oldboffin" I now have a replacement FDC board - which has solved the problem. I am now able to access floppy discs again. The computer is now back in working order, so the thread has served its purpose, unless there is any further discussion others wish to raise on this machine. __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)