Guy who came in from the cold

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KINGCHEF
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Guy who came in from the cold

Post by KINGCHEF »

Hi,
I started my computer experience with the QL and was in a small group in Cambridge until it's founder died and for a while afterwards, only six of us left by then.
I used the QL to run my restaurant business writing accounts program and recipes costing in Archive. I then moved on to the OPD / Tonto which became a bit of an obsession. All the kit ( heaps of it ) was packed away for and in a moment of madness unearthed this year. I ran a small group called the One Per Desk User Group and amassed a heap of equipment and lots of documents. To make space I took a car load over to the Computer Museum in Bletchley a few years ago and had a private tour in return.
Anyone with questions about OPDs can ask here.
I'm hoping to get my QLs working again.


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Chr$
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Re: Guy who came in from the cold

Post by Chr$ »

I think we've communicated before, over email a couple of years ago. Certainly the restaurant story is familiar. My monitor wasn't working and you provided some OPD schematics and other docs. I think I also bought something from you on ebay.

Welcome and hello.


https://QXL.WIN
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
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vanpeebles
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Re: Guy who came in from the cold

Post by vanpeebles »

A warm welcome! Would be nice to see some more info on the OPD.


KINGCHEF
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Re: Guy who came in from the cold

Post by KINGCHEF »

Chr$ wrote:I think we've communicated before, over email a couple of years ago. Certainly the restaurant story is familiar. My monitor wasn't working and you provided some OPD schematics and other docs. I think I also bought something from you on ebay.

Welcome and hello.
Hi,
How did it go with the monitor?

I had a colour one almost burst into flames with giant resistor heating up off the scale. I replaced it but the same thing happened. That's where my expertise ends.

I've been having my own troubles with the OPD. I have several sets of disk drives that tested working 2 years ago but now are very erratic. Much of the trouble was down to the floppy discs. I certainly didn't give a thought to the lifespan of a floppy. At one point 95% of my discs would not read. Now the only reliable discs are the originals from the supplier ( PCML). My accounts were backed up on floppies starting in 1988 or so. Not one would read on anything or re-format. Parity Failure, Disk absent or unusable, Data Error are terms that haunt my dreams. I thought I was having problems with dodgy microdrive cartridges but these..........................
The Teledrive needs an installation disc every time you fire up. Without it you cannot access the drives. I had multiple, multiple copies but these all failed one after another until only the originals remained. As a precaution I have done a disk image on to a PC hopefully to secure the disc contents.
I have been toying with the idea of using a Gotek drive on the OPD. It would still need the disc to initiate.
I sold a set of drives on eBay but doing a final test they refused to read the disc, so I refunded the buyer. She then came back and bought them anyway. She has used Gotek on other computers in her collection so I've asked for a summary of her experience.
Dave


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Chr$
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Re: Guy who came in from the cold

Post by Chr$ »

KINGCHEF wrote:
Chr$ wrote:I think we've communicated before, over email a couple of years ago. Certainly the restaurant story is familiar. My monitor wasn't working and you provided some OPD schematics and other docs. I think I also bought something from you on ebay.

Welcome and hello.
Hi,
How did it go with the monitor?
Gave up on that. It spent 6 months at the old-school TV repair man and I lost confidence that he was capable, so took it back and it went off to a new life with someone who had a technically good monitor with damaged case. When I fire up the Tonto I can use a old PC PSU and a scart TV for a pretty decent picture.
KINGCHEF wrote: I've been having my own troubles with the OPD. I have several sets of disk drives that tested working 2 years ago but now are very erratic. Much of the trouble was down to the floppy discs. I certainly didn't give a thought to the lifespan of a floppy. At one point 95% of my discs would not read. Now the only reliable discs are the originals from the supplier ( PCML). My accounts were backed up on floppies starting in 1988 or so. Not one would read on anything or re-format. Parity Failure, Disk absent or unusable, Data Error are terms that haunt my dreams. I thought I was having problems with dodgy microdrive cartridges but these..........................
The Teledrive needs an installation disc every time you fire up. Without it you cannot access the drives. I had multiple, multiple copies but these all failed one after another until only the originals remained. As a precaution I have done a disk image on to a PC hopefully to secure the disc contents.
That's a bit worrying. Are you able to write the images onto 'new' disks and if so do they work? Is the disk format the same as the QL? Can the file structure be read by anything else? I have no experience with OPD disks. I remember RWAP said he has a broken disk drive. All sounds like a headache. I expect there is a gotek way of doing it, but that will be reliant on being able to create working disk image files.


https://QXL.WIN
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
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Ruptor
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Re: Guy who came in from the cold

Post by Ruptor »

KINGCHEF wrote:
Chr$ wrote:I've been having my own troubles with the OPD. I have several sets of disk drives that tested working 2 years ago but now are very erratic. Much of the trouble was down to the floppy discs. I certainly didn't give a thought to the lifespan of a floppy. At one point 95% of my discs would not read. Now the only reliable discs are the originals from the supplier ( PCML). My accounts were backed up on floppies starting in 1988 or so. Not one would read on anything or re-format. Parity Failure, Disk absent or unusable, Data Error are terms that haunt my dreams.
It could be dust on the drive head which is why the floppies had sliding metal covers as well as hard plastic cases. Also try warming the disks to remove damp and expand them a bit that might make them line up tracks better. I have original microdrives that work and are more likely to fail than floppies. I just bought a USB floppy & Gotek so I shall see if my old floppies work from the days when windows was on 7 floppies, yes it did the same as now but was 8 Mbytes not 15 GBytes of Win10. :roll:


KINGCHEF
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Re: Guy who came in from the cold

Post by KINGCHEF »

Chr$ wrote:
KINGCHEF wrote:
Chr$ wrote:I think we've communicated before, over email a couple of years ago. Certainly the restaurant story is familiar. My monitor wasn't working and you provided some OPD schematics and other docs. I think I also bought something from you on ebay.

Welcome and hello.
Hi,
How did it go with the monitor?
Gave up on that. It spent 6 months at the old-school TV repair man and I lost confidence that he was capable, so took it back and it went off to a new life with someone who had a technically good monitor with damaged case. When I fire up the Tonto I can use a old PC PSU and a scart TV for a pretty decent picture.
KINGCHEF wrote:
How did you get the OPD to output to a SCART. I thought when my OPD monitors all fail I was finished!

I've been having my own troubles with the OPD. I have several sets of disk drives that tested working 2 years ago but now are very erratic. Much of the trouble was down to the floppy discs. I certainly didn't give a thought to the lifespan of a floppy. At one point 95% of my discs would not read. Now the only reliable discs are the originals from the supplier ( PCML). My accounts were backed up on floppies starting in 1988 or so. Not one would read on anything or re-format. Parity Failure, Disk absent or unusable, Data Error are terms that haunt my dreams. I thought I was having problems with dodgy microdrive cartridges but these..........................
The Teledrive needs an installation disc every time you fire up. Without it you cannot access the drives. I had multiple, multiple copies but these all failed one after another until only the originals remained. As a precaution I have done a disk image on to a PC hopefully to secure the disc contents.
That's a bit worrying. Are you able to write the images onto 'new' disks and if so do they work? Is the disk format the same as the QL? Can the file structure be read by anything else? I have no experience with OPD disks. I remember RWAP said he has a broken disk drive. All sounds like a headache. I expect there is a gotek way of doing it, but that will be reliant on being able to create working disk image files.
How did you get the OPD to output to a SCART. I thought when my OPD monitors all fail I was finished!

The PCML Teledrive disk format is basically PC format with some quirks that need file names to be changed. I did the image in the hope that, at least there was a copy. Getting it on to a disc might be a bit more of a problem. I think it would copy on to an OPD pre-formatted disc but a working disc would be needed. I've an idea that Dave Walkers DISCOVER had a template ( is that the word/) for the OPD disc and that I had used it. I was mainly thinking of the Gotek as it would then be an OPD disk image on a memory chip pretending to be an OPD disc?

The disc interface that RWAP has is one I sent him. This was made by COMPUTER ONE and was sent to me by 'a man down under' who had attempted a repair and totally destroyed it. The circuit is pretty simple. Uses a WD1770 chip, I think. Teledrive discs and Computer 1 discs are not compatible and it's not sure that C1 discs are PC format.


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Chr$
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Re: Guy who came in from the cold

Post by Chr$ »

KINGCHEF wrote: How did you get the OPD to output to a SCART. I thought when my OPD monitors all fail I was finished!
I had read that it was possible somewhere but never got round to doing anything... I had to change IC34 from a 74LS240 to a 74LS244 to invert the video and sync, and add a wire. Then I happened to notice a nice man on facebook called Matthew Smith who had created a scart/power combo cable that uses an old PC AT/ATX PSU. So to save me messing around, he made another and sent it to me very reasonably. It looks like this:
opdscart.jpg
Further info on the chip/mb mod under HOME BREW MODIFICATION OPTIONS:
https://rwapsoftware.co.uk/oneperdesk/t ... _info.html

There is also info on the same chip swap on the forum somewhere from a previous post where I was asking about it!
KINGCHEF wrote: The PCML Teledrive disk format is basically PC format with some quirks that need file names to be changed. I did the image in the hope that, at least there was a copy. Getting it on to a disc might be a bit more of a problem. I think it would copy on to an OPD pre-formatted disc but a working disc would be needed. I've an idea that Dave Walkers DISCOVER had a template ( is that the word/) for the OPD disc and that I had used it. I was mainly thinking of the Gotek as it would then be an OPD disk image on a memory chip pretending to be an OPD disc?
I don't think it's as simple as using a pre-formatted OPD disk as the image would overwrite everything. I know that when I create QL disk images (with SAMdisk, which is very good) that they are 'raw' and need to be converted to QL FAT format before you can do anything with them. The man who develops SAMdisk could probably provide a feature to convert raw images of OPD disks to OPD format, for writing onto any normal disk. Or are MS-DOS disks readable on an OPD (and vice versa)? If so, then it will probably be easier!

Oh, and here's a photo of the screen of an old LCD telly showing a Tonto screen through scart. Pretty damn good (even better when it's not a re-sized photo).
opdscartscreen.jpg


https://QXL.WIN
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
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