UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Computers

Notices

Vintage Computers Any vintage computer systems, calculators, video games etc., but with an emphasis on 1980s and earlier equipment.

Reply
 
Thread Tools
Old 19th Mar 2017, 3:14 pm   #1
Specmaster
Triode
 
Specmaster's Avatar
 
Join Date: Mar 2017
Location: Chelmsford, Essex, UK.
Posts: 21
Default Amstrad PPc512 and PPC640 luggable computers

I actually have one of each of these classic old machines which come with 2 x 720K 3.5" floppy drives built in.

Problem I'm having with them currently is that the boot up discs appear to be corrupted and while the 640 will boot, the 512 will not although it did 2 weeks ago.

I tried to make a copy of the boot disc the 640 discs and it comes with an "Error message" of an "Unrecoverable error" of one of the tracks.

I was just wondering if any of the gentlemen on this forum might be able to throw any light / assistance on thas matter please?

Graham
Specmaster is offline   Reply With Quote
Old 19th Mar 2017, 3:46 pm   #2
acollins22
Triode
 
Join Date: Oct 2010
Location: Leicestershire, UK.
Posts: 43
Default Re: Amstrad PPc512 and PPC640 luggable computers

Hello Graham,

If you haven,t already, I'd try using a head cleaning disk.

I don't know if the drives in the PPC are belt driven. I think most 3.5" drives are direct drive but most Amstrads (PCW and CPC) use drive belts. It the PPC drives are belt driven then it's highly likely that the belts have perished over the years and aren't driving the disk properly if at all.

I have a 3.5" drive from a PCW on my bench at the moment and the drive belt has stretched badly. I have a replacement on order and I'll see what happens.

All the best,

Andy.
acollins22 is offline   Reply With Quote
Old 19th Mar 2017, 4:18 pm   #3
Dave Moll
Nonode
 
Dave Moll's Avatar
 
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 2,893
Default Re: Amstrad PPc512 and PPC640 luggable computers

Certainly, the Amstrad 3" drives on the PCW and CPC are belt-driven (or rather gummed-up, as the belts have invariably perished), but I would have expected the 3" drives in the PPCs to be standard direct-drive units - though with Amstrad kit one can never assume things are standard, and I've never managed to acquire a PPC.

By the way, Andy, is the 3" drive in your PCW the one of a PcW10 or is it a replacement for an original 3" drive? Anyway, my expreience with the replacements available has generally been good. I even got away with using a correctly-sized rubber band on one unit - at least until I had access to the proper replacement!
__________________
Mending is better than Ending (cf Brave New World by Aldous Huxley)
Dave Moll is offline   Reply With Quote
Old 19th Mar 2017, 4:32 pm   #4
TonyDuell
Octode
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 1,459
Default Re: Amstrad PPc512 and PPC640 luggable computers

I am pretty sure the 3.5" drive in this unit is direct-drive. I certainly don't remember a belt either in the unit or in the service manual (I have both).

The drive is a standard 720K 3.5" unit. Standard connectors. In fact the inside of the PPC (apart from the LCD driver) are very much what you find in the first series of desktop Amstrad PCs. I am pretty sure some of the gate arrays are identical, for example.

I still use mine. I have a single drive one, wth a DC37 socket in place of the second drive. I use it with a thing called a Microtest which is a specialised device for testing and aligning floppy drives. Useful if you have as many classic computers as I do. I never had the official PSU, so I made one (transformer, rectifier, smoothing capacitor). On the grounds I fitted primary and secondary fuses and it's in a diecast box it's probaby better than the original.
TonyDuell is offline   Reply With Quote
Old 19th Mar 2017, 5:23 pm   #5
Specmaster
Triode
 
Specmaster's Avatar
 
Join Date: Mar 2017
Location: Chelmsford, Essex, UK.
Posts: 21
Default Re: Amstrad PPc512 and PPC640 luggable computers

Many thanks for the info and help so far chaps, I didn't expect to get results with such speed. The drives are infact direct drive as suspected and everything appears to be working as good as the day as they left the factory.

Both machines are in really good condition, look like they have never had batteries fitted so no corrosion in that dept. The only problem with the 512 is the slight discolouration of the plastics seeing as it was the lighter of the 2 originally.

Problem that I do have is that I only ever had 1 set of boot discs between the pair and I never got around to making a duplicate until today and that was when I discovered that the 512 never booted correctly, it beeped, the screen showed "Please wait" and then went blank after a few minutes and the disc drive stopped spinning.

The same boot disc will boot the 640 no problems whatsoever, so I set about making a back up copy for the 512 and used the command Diskcopy to copy the boot disc and it gives me the error of an unrecoverable error when trying to read the boot disc in preparation for copying it. It does carry on and appears to be copying and asks for the source disc to be removed and the destination disc to be swapped over at various points along the way, which I do.

When I check the directory contents of the new disc, it is blank and the disc name is a jumbled set of characters.
I then went to this link http://www.retroisle.com/amstrad/pcs/software.php and downloaded the compressed floppy image files of the 2 discs required. In the folder is a readme file and the following is what it says.
“PPC System disks
================

This archive contains images of the two system disks that were originally supplied with the PPC 512 and PPC640. Disk 1 contains MS-DOS .3 and a copy of the "Organiser" program while disk 2 contains the "Mirror" communication software that was designed for use with the modem built into the PPC640.

To make new copies of the system disks take two floppy disks that have been formatted to 720K (NOT! 1.44MB) and then give the command:

FDCOPY DISKn.CFI A:

where n is 1 or 2 and A: is the drive containing the 720K floppy disk. This will use the FDCOPY.COM that is also in the ZIP file to resurrect the complete compressed floppy image (CFI) onto the disk.

Cliff Lawson
cliffl@amstrad.com

My main PC runs Windows 10 and FDCOPY is not a windows command and so the system blocks it from being run. Putting the discs into the 640 and running the command simply makes a copy of the compressed file for disc1 onto a blank disc inserted into drive B, it does not extract it at all.

I wanted to try and do this case my original discs might have been corrupted by the presence of a magnetic field etc?

I have tried everything I can think of trying to get a fresh copy of the boot up disc made without any success.
Specmaster is offline   Reply With Quote
Old 19th Mar 2017, 6:11 pm   #6
acollins22
Triode
 
Join Date: Oct 2010
Location: Leicestershire, UK.
Posts: 43
Default Re: Amstrad PPc512 and PPC640 luggable computers

Quote:
Originally Posted by Dave Moll View Post
By the way, Andy, is the 3" drive in your PCW the one of a PcW10 or is it a replacement for an original 3" drive?
My machine is actually a PcW9512+ (Lower case c) and as far as I know, came with a 3.5" drive. this has a different connector to the usual 3.5 inch drive but I don't know if it's the same as an Amstrad 3 inch unit.
acollins22 is offline   Reply With Quote
Old 19th Mar 2017, 6:53 pm   #7
Specmaster
Triode
 
Specmaster's Avatar
 
Join Date: Mar 2017
Location: Chelmsford, Essex, UK.
Posts: 21
Default Re: Amstrad PPc512 and PPC640 luggable computers

The 9512 did only come with a 3.5" drive, it was the 8256 that had the 3" drives.
Specmaster is offline   Reply With Quote
Old 23rd Mar 2017, 7:13 pm   #8
mike_newcomb
Hexode
 
Join Date: Apr 2012
Location: West London, UK.
Posts: 459
Default Re: Amstrad PPc512 and PPC640 luggable computers

Hi Graham, to be honest I am a little confused as two machines are involved and much has been posted above. Therefore, I will simply list my thoughts, as this is how I would approach the problem

Ensure all master discs are write protected

On the machine that loads, are you able to copy the boot disk(s) and then will they boot on the same machine. This will prove the copies are good

On the machine that does not boot, can the drives be swopped (e.g.so B: becomes A
for test purposes. Maybe by just a Ribbon Cable move.

Floppy drives can be cleaned, my removing the top, then blowing out any muck with a Hair Drier set to cold and max blast. Use a long thin brush to assist. Gently clean the heads with a (bent) Cotton Bud dipped in IPA.

I think the os on least on of the machines is DR-DOS not MS-DOS.

Belief a CFI file is compressed, so files need be extracted before use.

When creating a System Disk with MS-DOS, the /S parameter need by used in order to copy the 2 or 3 hidden system files.

See note 3 here:-
http://git.net/ml/os.drdos.general/2.../msg00000.html

Good Luck - Mike
mike_newcomb is offline   Reply With Quote
Old 23rd Mar 2017, 10:37 pm   #9
dave walsh
Dekatron
 
Join Date: Jan 2006
Location: Ramsbottom (Nr Bury) Lancs or Bexhill (Nr Hastings) Sussex.
Posts: 3,065
Default Re: Amstrad PPc512 and PPC640 luggable computers

I can't get too technical here Mike but I had a 9512 that had some sort of problem. My technician friend came around but couldn't help. Despite me pointing out that it warned you in the manual NOT to switch on without the printer plugged in-he did As a result it appeared to be completely b******d. Apparently the main [only] chip was destroyed if you did this [somehow].
I discovered later that the only possible repair was another chip. I found a supplier but didn't pursue that in the end. I'm pretty sure it was the Markl 1 version though.

My technical knowledge is very limited and I doubt if this story will help you much but it might have been worth repeating. Of course the notion of a computer with no memory except on the individual floppy discs would be hard to get across to most people these days-like a phone that just makes calls

Dave W
dave walsh is offline   Reply With Quote
Old 24th Mar 2017, 12:49 am   #10
emeritus
Octode
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 1,779
Default Re: Amstrad PPc512 and PPC640 luggable computers

My experience with the floppy disks that I used to use with my PCW512 (3" and 3 1/4" ) and Windows 98 PC (3 1/4") was that it was very difficult to corrupt their data using magnets. I did try my best, holding the window open and stroking the end of a powerful rod magnet across the magnetic disc surface while, ditto with an electromagnet made from a soft iron rod wound with many turns of wire, connected briefly directly across a 12V car battery, but was unable to induce a single error. However, I did experience a number of disks that exhibited faulty sectors when I tried reading them to transfer files onto my new PC computer several years after they had last been checked. Fortunately I always used to save at least two copies of disks used for archiving. Reformatting the disks never fixed the errors, but the disks were then usable with reduced capacity.

Unlike the 3" disks, different magnetic material is used in the disks of 720k and 1.44M 3 1/4" disks, so even if you cover up the hole in a 1.44 disk to format it to 720k the results are likely to be disappointing. I tried both using the floppy drive of my WIN 98 PC and the external 720k 3/14 " disk drive that I got for my PCW8512 that could be used to format disks to either the PCW format or MS-DOS format for exporting ASCII text files to a conventional PC. Before I managed to obtain a good stock of the proper 720k disks, I did sometimes get it to work, but it took an age to write as repeated write actions were necessary.

Last edited by emeritus; 24th Mar 2017 at 12:56 am.
emeritus is offline   Reply With Quote
Old 24th Mar 2017, 12:26 pm   #11
Specmaster
Triode
 
Specmaster's Avatar
 
Join Date: Mar 2017
Location: Chelmsford, Essex, UK.
Posts: 21
Default Re: Amstrad PPc512 and PPC640 luggable computers

Quote:
Originally Posted by mike_newcomb View Post
Hi Graham, to be honest I am a little confused as two machines are involved and much has been posted above. Therefore, I will simply list my thoughts, as this is how I would approach the problem
Ok, to try and clarify the situation. Yes there are 2 machines, a PPC640 and PPC512 and I only have 1 set of discs between them.

The last time I used them was about 12 months ago and both worked perfectly using the same operating system discs. I went to use them again a couple of weeks ago and only the PPC640 would boot from the floppy disc.

The PPC512 would go through the normal boot process and then would terminate with a blank screen, no beeps from the machine to indicate an error code..

Anyway at that point I decided that I really ought to make back up copies of the set of discs for security reasons alone.

Bareing in mind that the PPC640 boots and loads all the other discs on demand with no problems and also functions perfectly, so it was a surprize to me that while attempting to copy the operating boot disc, when it threw up an error message about an unrecoverable read error on the source disk. So that then terminated my attempt to create back-up discs.

The command of FDCOPY is not on the set of discs that I have for the machines so is this DR-DOS command?

They will work happily with either MS-DOS or DR-DOS, I used to have PC512 with a huge 30Mb hard drive and I replaced the supplied MS-DOS with DR-DOS as it was both faster and seemed to a better command set and I never had any issues with it.
Specmaster is offline   Reply With Quote
Reply

Thread Tools



All times are GMT. The time now is 10:44 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright ©2002 - 2017, Paul Stenning.