11th Feb 2021, 9:14 am | #141 | |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Quote:
The KT5 caps were 12x12mm to fit 12mm-Square switches. And the KT7 was 7.4x7.4mm to fit 6mm (tall soft-touch) KEF10901 6mm-Sq. switches. I've just found this nice sample-kit photo: https://www.firstpr.com.au/rwi/tr-80...ample-card.jpg via this webpage on Alps keyswitches: https://telcontar.net/KBK/Alps/elastic_contact#types Unfortunately, all of these seem to have completely vanished from being sold anywhere these days. Whereas at least the once-popular Low-profile 12.7mm-Square diagonal-pins 'RS' 337-598/605/611 Red/Blue/Grey fitted-top ones were available until much-more recently - Although the Omron? / C&K etc. 'D6' round-with-flat-edge ones at least are still available and in many colours / could also get completely flat-top square over-caps for these, to make a more conventional keyboard without gaps between tops. |
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20th Feb 2021, 7:40 am | #142 |
Octode
Join Date: Mar 2020
Location: Kitchener, Ontario, Canada
Posts: 1,294
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Re: Softy 1
Does softy support hot swapping the 2708, or does the softy need to be powered down when the 2708 in the programming socket is fitted or removed?
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20th Feb 2021, 12:43 pm | #143 | |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Quote:
They also both share the same Data & Address lines, just using chip-selects to swap between these (The INS8154 PIA is mainly only used to read the keyboard) So not an especially safe design, for swapping the EPROM whilst powered-up - especially with 3-rail devices, and virtually live-swapping (apart from chip-selects). So even if using a ZIF-socket, you may be able to crash the unit when changing the EPROM, if chip-selects don't get connected first / disconnected last along with ground. |
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20th Feb 2021, 1:09 pm | #144 | |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Quote:
I knew Barry Savage had a Videotime Products company, to sell the Tolinka Chess-Display he'd designed (and for which the Softy was also designed, as a development aid for it before it being suggested that this should be sold as well) And GP Industrial Electronics was the name on the Softy manual, so it appeared that Dataman had just been distributors (as I recall GP Industrial Electronics requesting distributors). With Watford & Technomatic etc. later selling the (Dataman) Softy-2. Although it seems Dataman (often originally listed as Softy in WW Advertising index but with Dataman in the address details), had started advertising it before GP briefly did in there. GP Industrial Electronics had stopped advertising the Softy in WW magazine, before 1982 (and never advertised the Softy-2 in there), then totally-stopped advertising some time between 1983 & 1987. But according to this it looks like they may have still been around until 1991 at least: https://companycheck.co.uk/company/0...ies-house-data Although no info as to if they were taken over, or just eventually ceased trading. |
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20th Feb 2021, 1:31 pm | #145 | |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,560
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Re: Softy 1
Quote:
Go to digikey.co.uk and do a search on "C&K MDP series" That will return hits in two categories, "Accessories- Caps" and "Pushbutton Switches" In one you'll see the switches available in various Newton-force options and in the other, the low profile dimpled keycaps in a range of colours. These are actually the exact type of switches the after-fit keypad on my original MK14 is made with, although that was made not long after I got the MK14. |
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20th Feb 2021, 1:45 pm | #146 |
Octode
Join Date: Mar 2019
Location: Barry, Vale of Glamorgan, Wales, UK.
Posts: 1,363
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Re: Softy 1
I think looking at the original Softy KB they are round switches with a printed split colour card or plastic overlay on the top with just slightly larger round holes in them - which would have been cheaper than etching square keycaps or cutting square holes in an overlay?
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20th Feb 2021, 2:14 pm | #147 | ||
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Quote:
Thanks. Yes, these do appear to be the same as ones RS used to sell (But RS only sold with pre-fitted caps in Red/Blue/Grey, although they pop-off / back on the switch's actuator '+' shape with pair of sprung sides) Whereas the 'C&K MDP' ones that Digikey stock have caps in a few more colours - The ITT-Cannon datasheets they have, show 6 (pre-fitted?) colours As well as options to have gold or silver plating, depending upon required current rating / application. I think I also found C&K still sell 'D60' switches (used for reset / interrupts on Acorn system 6502 board / Chris has pinned his MK14 board to take), but in a few more colours than what I'd originally found (which had already been a few more than the 3 that the old 'RS ' (Now C&K MDP) had been available in |
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20th Feb 2021, 2:23 pm | #148 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,560
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Re: Softy 1
My MDP switches came from a seller who sold the switches and caps separately in singles, but they only ever stocked the red and blue keycaps, so my ambition to have the numeric keys, alpha keys and command keys each in a different colour was never realised.
I should really buy some spare keycaps while I still can and finally do the command keys in grey or black as I had originally intended. I already have four spare MDP switches in my kit of spares for the MK14. |
20th Feb 2021, 2:39 pm | #149 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Yes, The ones I've got in my (Wireless World 6802) NanoComp, are in all 3 original colours (although Only Re for Reset). And it does also have transparent printed stickers on each of the buttons.
Although the dark-grey printing isn't a great contrast (especially on light grey), and now they are available in white that may have been better (or replace the clear labels with white-printed as used on black keyboards) |
11th Mar 2021, 12:28 pm | #150 |
Pentode
Join Date: Jan 2021
Location: Northampton, Northamptonshire, UK
Posts: 131
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Re: Softy 1
My replica SOFTY 1 is finished and working !
There where no problems with the schematic but annoyingly I built the phono socket (video output) incorrectly so that the connections are reversed, easily fixed by wiring the plug reversed. A couple of other minor things - I'd put the edgeconnector fingers at the keyboard end on the underside of the PCB and they should be on top and labelled LK4 reversed. On the whole nothing serious. Details are here: http://www.theoddys.com/acorn/Replic...a_softy_1.html Just got to finish the power supply. Chris |
11th Mar 2021, 12:38 pm | #151 |
Heptode
Join Date: Oct 2011
Location: Culcheth, Cheshire, UK.
Posts: 654
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Re: Softy 1
Great stuff, well done !.
Now can you post some pics of the TV screen, so I can relive my experience of the SOFTY a bit better !. |
12th Mar 2021, 11:42 am | #152 |
Pentode
Join Date: Jan 2021
Location: Northampton, Northamptonshire, UK
Posts: 131
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Re: Softy 1
Here's a photo off my NOVEX monitor. Not brilliant as the camera didn't like the glass front or scanning image (and I'm not a photographer !) but should do the trick for those wanting a bit of a nostalgia fix.
Interestingly the whole picture is over to the left, this was the same with a TV so its not the monitor. Vertically there is some skew (not sure what the correct video term is ?) particularly where the background intensity varies between blocks. I'll investigate to see if this can be improved by any tweaks to the SOFTY. Chris |
12th Mar 2021, 9:23 pm | #153 |
Pentode
Join Date: Jan 2021
Location: Northampton, Northamptonshire, UK
Posts: 131
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Re: Softy 1
I've had a look at the video circuit to see if the horizontal start can be delayed and it can by reducing the value of C10 which generates the horizontal sync pulse however this increases the vertical distortion.
I think the problem is coupling between the various signals that are combined to produce the final composite video signal, you can see jitter on the horizontal sync pulse IC5 pin 10. Probably the only way to improve things is to add some additional buffering to e.g the block highlight signal from R7 and to drive C10 ? Its perfectly useable as is so I think I'll leave it alone ! Chris |
13th Mar 2021, 4:55 pm | #154 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Thanks for the screenshot. Regarding getting a decent capture, do you have a USB video capture device / an old PCI TV Tuner card with this (& PC to take it!)
I was surprised that it goes off all 4 edges of the screen, and there doesn't seem to be any borders - Do you get the same on Derek's one? (I think he mentioned display issues, but that was probably when it was faulty with all the failed IC's) And if this is on your monitor, can you adjust the height /width of it from front / rear controls, to see if all the content is actually in the video signal (but maybe in the parts that are normally off-screen) ? |
14th Mar 2021, 9:23 pm | #155 |
Pentode
Join Date: Jan 2021
Location: Northampton, Northamptonshire, UK
Posts: 131
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Re: Softy 1
The picture was pretty much the same on Dereks SOFTY so not a fault, also the same on a TV. My NOVEX monitor doesn't have any controls to adjust picture position width etc.
I don't have any video capture things I'm afraid so can only photograph the screen. Chris |
14th Mar 2021, 11:08 pm | #156 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
Thanks for info. I presume Derek must have tapped-off composite video when he'd been testing it, as it doesn't originally have an output connector for it.
Have you tried using your GBS-8200 RGBS / Composite to VGA converter with it, to see what that's like? I also recently found you can get converters to HDMI for < £6! So if any of these converters work, you might be able to use on-screen menu picture adjustment controls on a more modern digital monitor. (May also be able to photograph these easier, if less reflective than a CRT) |
14th Mar 2021, 11:13 pm | #157 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,560
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Re: Softy 1
Chris, did you manage to get the original machine working as well? I assume so since you're talking about the video output from that one being similar. If so, what turned out to be wrong with it? (I know you already mentioned that the processor was dead).
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14th Mar 2021, 11:32 pm | #158 |
Pentode
Join Date: Jan 2021
Location: Northampton, Northamptonshire, UK
Posts: 131
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Re: Softy 1
The machine turned out to have several faulty ICs:
IC20 CPU IC4 2102 RAM IC10 or 14 2114 RAM (just one of the pair) IC6 or 7 4503 (just one of the pair) IC18 4011 A small number of the keyboard switches are not working, fortunately none that were needed for testing, I imagine these can be fixed with a little TLC. The only other problem was that the modulator wouldn't drive my TV though it is producing modulated RF when viewed on a spectrum analyser ? Derek had added a video connection which worked fine with my Novex monitor. Considering its age there was an expectation that there would be issues with the soldered vias or IC sockets but all are OK. Once the faulty ICs were swapped out I did manage to successfully program a couple of 2708s with it. Its now on its way back to bygonebytes. Chris |
14th Mar 2021, 11:40 pm | #159 |
Octode
Join Date: May 2018
Location: Northampton, Northamptonshire, UK.
Posts: 1,440
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Re: Softy 1
With the 4503 Hex Tristate Buffer & 4011 Quad Nand gate, did you find out if there was just one of the devices in it that was faulty or if the whole IC was faulty?
- I did wonder that if a single part had gone, then there might be a clue to how it failed from what it connects to on the circuit (although less clear for the 4503, if you didn't know which of a pair they came from) |
15th Mar 2021, 12:01 am | #160 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,560
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Re: Softy 1
That's quite a casualty list on the original machine - seems almost miraculous that the programmed devices somehow survived.
For the RF/Video problem I wonder if it is just that the video waveform doesn't quite meet the spec, as per the video signal produced by early ZX81 ULAs and no doubt a few other video-producing devices of the time. Mono TVs from the same period as the Softy don't care about that at all, but later models seem to be more fussy about black level / back porch all being as they should be. LCD TVs are even more fussy. If you can borrow / lay hands on an old 12" Ferguson / Ultra / Binatone, etc mono portable TV, I would be surprised if it did not work perfectly with something like that. |