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Spectravideo SV 328- are power and video output compat with other machines?

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SVI-318 and SVI-328 use the same power supply, a four prong one with 9VAC + 16VAC. It has been reported that the SVI-728 uses the same voltages and pinout, so these three should be compatible

 

There were some 3rd party floppy drives for the Commodore too, namely the Blue Chip and FD-148 (may have existed under additional names) that seem to be a perfect match for the SVI computer line, both in terms of pinout, voltages and ampere.

 

svi728powerconnector.gif

 

Note however that the ColecoVision and the TI-99/4A use the same connector but different voltages and pinouts, so power supplies from these systems shall not be used with the Spectravideo.

 

Not only are dual AC transformers a bit hard to find, the connector although used by a number of manufacturers, is hard to find and as far as I know doesn't have a designator to search for. I have understood that any genuine 1541 floppy drive internally has a transformer that will generate 9VAC + 16VAC which then are rectified and regulated down to 5VDC + 12VDC that the 1541 internally use. I've got a spare, partly broken 1541 that I'm planning to attempt to reuse the transformer from in order to power another 9+16 system present in your signature (but with a regular 5-pin DIN connector).

 

Video is much easier. The SVI line has a 5-pin DIN for A/V that happens to follow the same pinout as most Atari 8-bits, VIC-20, C64 when it comes to just composite video and audio, so if you have a cable used for one of those, it should work right away. Note though that the Sega Master System, Mega Drive, Neo Geo (?), MSX etc use a different pinout on their DIN A/V ports, so avoid using a cable intended for one of the latter mentioned systems. Actually if you just plug in the audio, all cables should work but the video is on a different pin on Atari/Commodore vs Sega/MSX.

Edited by carlsson
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FYI, you can also use the F18A with the SVI-328 (I have personally tested on that system). so VGA is a video output option if you want.

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I can vouch for both the standard video cable (8-bit, Vic-20, etc) and the F18a as I've used both. In fact my system was the one Matt tested it on.

 

A replacement power supply is going to be hard to find. I was looking for a US one forever before I gave up and used my European one with a voltage converter. I have no idea why SVI made such a wonky power supply (not not mention it weighs a metric ton) but there doesn't seem to be any cheap replacements.

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I have no idea how wonky the original power supply is, but it appears that the combination of 9V AC + 16V AC isn't that unusual as one first might think. Nowadays I think an R-Core preamp transformer might be suitable, even if those output 9V AC + 15V AC the voltages likely will be rectified and regulated inside the computer. I still believe the connector should have a name since it was used by several manufacturers, but I don't know what it is called and I never found a generic one that matches the pin layout.

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I have recently purchased an SV-328 but it does not have a power supply. Any idea where I could get one or what I could use to build one?

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You may have some options in my post #2 above, but I won't be held responsible for any damage. In particular, I haven't got to disecting that 1541 floppy drive yet, and in the SVI case you still need a four prong female connector. If the gender had been swapped, you could have stuck wires directly into it.

 

Here is a DIY to make a connector (intended for the TI-99/4A but as noted the connector is physically the same, just different electrically)

http://oldcomputer.info/8bit/ti99/index.htm#powerplug

 

Furthermore, since I noted you're from the ColecoVision community, perhaps the same DIY could be useful to those people too unless you already have better methods.

 

Edit: I noticed there was someone in the CV section who CNC:ed his own connectors, but that user is no longer active. I have a feeling there would be a market for the connectors themselves, as well as ready made power supplies for the various systems using them.

Edited by carlsson
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Making ones own Spectravideo power supply

It’s extremely hard to find a working or broken Spectravideo power supply. I do not see any pinout information for the Spectravideo power supply. If I could measure a working power supply then I would know which pin or pins are ground, and which pin or pins is used for 16 volts AC and 9 Volts AC. The USA version of the Spectravideo power supply are so rare that pictures do not exist online. Every picture that I have seen so far for the Spectravideo power supply is for the European model. It is my understanding that both the USA NTSC SpectraVideo SV-318 and SV-328 and the Europe PAL Spectravideo computer power supplies output 16 volts AC at 0.8 amps max and 9 volts AC at up to 1.5 amps max. However since I have never seen a USA Spectravideo power supply that information needs to be verified.

 

 

Since we know for sure the European power supply specs. Then if one wanted to use a European PAL Spectravideo system in the United States, then one could de-solder the power cord from a broken Spectrvideo power supply and make their own power supply. The following is not the ideal solution, however it should work and this solution is legal for resale since it uses two level VI energy efficient wall transformers. For North America consumers only since the two power supplies are 120 volts AC at 60Hz: Purchase a 16 volt AC Traid WAU160-750T-S UL listed and efficiency level VI adapter for around $14 and a 9 volt AC Triad WAU090-1200-S UL listed and efficiency level VI adapter for around $14. There is also the 16 volt AC WAU160-750T-SG that has the grounding terminal and the 9 volt AC WAU090-1200-SG that has a grounding terminal.

 

Grab the power cable that one de-soldered with the special 4 pin connector on the end. Then one screws the two bare 16 volt AC wires on the two 16 volt AC terminals of the 16 volt AC power supply and the ground wire on the ground terminal of the 16 volt AC power supply, that is if the ground wire is used (have to see the pinout information). Then one takes the two 9 volt AC wires and screws those wires on the 9 volt AC terminals of the 9 volt AC power supply and the ground wire to the ground terminal of the 9 volt AC power supply if the ground wire is used (have to see the pinout information). I have not tried this but it might work, however it is not the ideal solution since it uses two wall transformers instead of one. One other issue is that the 16 volt AC adapter mentioned above is only 0.75 amps and the original Spectravideo adapter outputted 0.8 amps. In addition, the 9 volt AC adapter mentioned above is only 1.2 amps and the original adapter is 1.5 amps. Therefore this would need to be tested to verify that it works, however it might work if the Spectravideo system does not draw the full current of what the original Spectravideo AC adapter puts out. However, for under $30 for two power supplies and a 10 year warranty that well be attractive for some Spectravideo owners.

 

 

There might be another way to power the Spectravideo computer system since internally the computer system converts AC to DC. On the ColecoVision game system, when the Expansion Module #3 ADAM computer is plugged into the front 60 pin expansion module interface the 4 pin ColecoVision power supply is no longer used since the ADAM computer powers the ColecoVision over the 60 pin expansion edge connector. According to the Spectravideo pinout information online , pin 1 is + 5 volts DC, pin 3 is +12 volts DC, and pin 4 is -12 volts DC. With an ATX power supply and a specially made 50 pin Male edge connector cable the Spectravideo computer system in theory could be powered by the 50 pin male edge connector (However the pinout information claims those voltages are output only, however those voltages might be bi-directional just like the 60 pin ColecoVision expansion module interface).

Edited by HDTV1080P

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Two high-end BETA RF TV cables for the Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M

Some older 20th Century tube TV’s and even some modern 2018 flat panel screens do not have a composite video input. Instead the only way to connect ones Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M is by using the built in RF modulator connected to the TV’s NTSC RF antenna input.

 

One negative feature of the Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M is that the standard female RCA jack was not used for the built in RF modulator. Instead, one needs to have a special DIN cable that accesses the RF modulator on pin number 5.

 

I had Cables Online make up a special state of the art BETA RF cable for the Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M. Pictured below is a ADR-300 6 inch 5 pin Gold plated RF cable with a female f connector that allows one to connect up to a 100 feet RG-6 Quad shield cable. Also pictured below is an ADR-506 6 feet 5 pin Gold plated RF cable with a gold plated male f connector that uses 18 gauge QUAD shield RG-6 cable. These cables have not been released on the market yet. However the ADR-300 has a suggested list price of $20.95 and the ADR-506 suggested list price of $24.95.

 

However on my Yamaha CX-5M computer that has a built in AC power supply, I have discovered that on some of the Yamaha CX-5M computers that pin 5 was not connected because a built in RF modulator was not offered on a select few Yamaha CX-5M computers. Plus after several decades the internal RF modulators are sometimes defective.

 

Therefore since I do not have a Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M computer with a working RF modulator I am unable to successfully test Cables Onlines new ADR-300 and ADR-506 cables. So the cables pictured below are BETA cables that might never be released. Also the composite video and audio output cables that people are already using with their Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M computers are better quality then a RF cable.

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Edited by HDTV1080P

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High-end Gold Plated composite video and audio cables

It has been verified that the $20.95 Cables Online ADX-300 6 inch Gold Plated 5 pin DIN plug that works with RG-6 RCA style cables up to 100 feet is 100% compatible with the Spectravideo SV-318/SV-328, Sony HB-10, and Yamaha CX-5M computers. The same is true for the $24.95 Cables Online ADX-506 6 feet Gold Plated 5 pin DIN plug.

 

Composite video output was the best quality output for these classic 80’s computers without doing some type of internal modifications.

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Edited by HDTV1080P

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Spectravideo North America 120 volt power supply (Blue Chip model number 108-138)

I just purchased a Spectravideo USA/North America power supply (Blue Chip model number 108-138). This UL listed power supply was made for the Spectravideo SV-318 and SV-328. The only real difference between the Spectravideo European model number 318-201, is that the European model has a input of 220 volts at 50Hz (35 watts) and the USA/North American Spectravideo Blue Chip model number 108-138, has a input of 120 volts at 60Hz (36 watts). Both the USA/North America and European power supply outputs 16 volts AC at 0.8 amps and 9 volts AC at 1.5 amps. Therefore the only difference on the output of the adapters is that the European model outputs 50Hz and the USA/North America model outputs 60Hz. However since internally the Spectravideo computers convert the AC voltage to DC, the 50/60Hz issue is a non-issue and does not matter when it comes to the main computer itself. This means someone that purchased a Spectravideo computer in Europe can use the computer in North America if they buy the correct 120 volts 60Hz AC power supply, or a NTSC North America computer can be used in Europe if they buy the correct 220 volts 50Hz power supply.

 

The following is a picture of what the UL listed Spectravideo USA/North America power supply (Blue Chip model number 108-138) looks like. Both the European and USA/North America Spectravideo power supplies are unregulated power supplies. For example with no load on the circuit, the power supply was outputting around 18.24 volts AC and around 10.55 volts AC. However, this Spectravideo unregulated power supply puts out around 16 volts and 9 volts when under a load from the Spectravideo computer system. A combination of a special 4 pin power connector with dual AC output makes this power supply the most difficult or one of the most difficult power supplies to replace when it comes to classic 80’s computers.

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Edited by HDTV1080P
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On 12/14/2018 at 8:58 PM, HDTV1080P said:

Spectravideo North America 120 volt power supply (Blue Chip model number 108-138)

 

I just purchased a Spectravideo USA/North America power supply (Blue Chip model number 108-138). This UL listed power supply was made for the Spectravideo SV-318 and SV-328. The only real difference between the Spectravideo European model number 318-201, is that the European model has a input of 220 volts at 50Hz (35 watts) and the USA/North American Spectravideo Blue Chip model number 108-138, has a input of 120 volts at 60Hz (36 watts). Both the USA/North America and European power supply outputs 16 volts AC at 0.8 amps and 9 volts AC at 1.5 amps. Therefore the only difference on the output of the adapters is that the European model outputs 50Hz and the USA/North America model outputs 60Hz. However since internally the Spectravideo computers convert the AC voltage to DC, the 50/60Hz issue is a non-issue and does not matter when it comes to the main computer itself. This means someone that purchased a Spectravideo computer in Europe can use the computer in North America if they buy the correct 120 volts 60Hz AC power supply, or a NTSC North America computer can be used in Europe if they buy the correct 220 volts 50Hz power supply.

 

The following is a picture of what the UL listed Spectravideo USA/North America power supply (Blue Chip model number 108-138) looks like. Both the European and USA/North America Spectravideo power supplies are unregulated power supplies. For example with no load on the circuit, the power supply was outputting around 18.24 volts AC and around 10.55 volts AC. However, this Spectravideo unregulated power supply puts out around 16 volts and 9 volts when under a load from the Spectravideo computer system. A combination of a special 4 pin power connector with dual AC output makes this power supply the most difficult or one of the most difficult power supplies to replace when it comes to classic 80’s computers.

post-10892-0-61401900-1544840105_thumb.jpg

post-10892-0-02964600-1544840171_thumb.jpg

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I have a minor correction to make to my prior post. When I purchased the Blue Chip brand of power supply, it was advertised as a Spectravideo power supply. However, when I did some more researching I discovered that the Blue Chip brand power supply was made and shipped with the Blue Chip Commodore compatible Disk Drives back in 1985. However it has been verified that the United States 1983 Spectravideo 318 and 328 computer systems power supply has the exact same connector, shape, color, and input/output voltage and current specs as the 1985 Blue Chip power supply made for the Commodore compatible Disk Drives back in 1985. The only difference between the Blue Chip brand power supply and the Spectravideo brand power supply is the label on the power supply has a different brand name.  

 

Another issue is I have never seen anyone post a picture of the North America version of the Spectravideo 318 and 328 computer system power supply. All pictures online are either someone posting a picture of the USA 1985 Blue Chip brand power supply or the European 220 volt Spectravideo power supply. Spectravideo had at least two different versions of the European power supply. The first unregulated European version used 36 watts of power, however the second unregulated European version has a slightly better energy efficiency and only used 35 watts of power.  Both power supplies output 16 volts AC at 0.8 amps and 9 volts AC at 1.5 amps.

 

There must have been only 50,000 to 100,000 NTSC Spectravideo 318 and 328 computer systems made in the Untied States (The Coleco ADAM had around 500,000+ systems made and was much more popular computer system). In fact there must have been more Blue Chip Commodore compatible Disk Drives made when compared to the USA version of the Spectravideo computer system.

 

Does anyone have an actual picture of the North American Spectravideo power supply that has an input voltage of 120 volts at 60Hz? It would be nice to see. One might need to purchase a NTSC North American version of the Spectravideo computer system in order to see what the power supply label looks like.

 

Edited by HDTV1080P

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Several companies had a different style of plastic 4 pin mold

 

In June 1981 Texas Instruments came out with their plastic mold for the TI-99/4a computer, then in August of 1982 Coleco came out with their plastic mold for the ColecoVision. In 1985 Blue Chip came out with their plastic mold for the Blue Chip Commodore compatible disk drive. There was also a fourth plastic mold for the Spectravideo 318 and 328 computer systems, which was exactly the same plastic mold as the Blue Chip brand.

 

Even though all the plastic molds are a little bit different, the 4 pin connector is exactly the same and the cable assembly can be swapped between the 4 different brands as long as a different power supply is used (even though the power supply connector fits, only use a TI-99/4a power supply on a TI-99/4a computer, and a ColecoVision power supply should only be used on a ColecoVision ** Placing the wrong power supply on the wrong computer or video game system could fry the circuit board **). The Texas Instrument plastic mold which was the first one that came on the market does not have as good of quality of plastic when compared to the ColecoVision mold. The Blue Chip plastic mold is thicker and bigger. I believe the Texas Instruments and Coleco plastic mold use 20 gauge cable and since the Blue Chip plastic mold uses a thicker cable it might be 18 gauge cable.

 

 

3 differnt molded power cords view 1.JPG

 

 

3 differnt molded power cords view 2.JPG

 

 

ColecoVision power cable.JPG

 

Last picture Coleco version

Edited by HDTV1080P

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The Blue Chip power supply connector has the official Spectravideo name on the connector, so instead of designing their own plastic mold from scratch they decided to use the official “Spectravideo” connector. But still it is my understanding that Spectrvideo had its own brand of power supplies in the United States and the computers did not actually ship with a Blue Chip power supply.

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I have come to the conclusion that Spectravideo more or less manufactured the power supplies for the Blue Chip series, Amtech FD-148 & RF501C and the DS64 floppy drives. Those seem to be more or less OEM so possibly those brands only existed on paper.

 

For that matter recently a STL file was made available for anyone with a 3D printer to get your own connectors that will fit all those with a bit of DIY. Of course you still need to come up with the dual voltage AC supply.

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3 hours ago, carlsson said:

I have come to the conclusion that Spectravideo more or less manufactured the power supplies for the Blue Chip series, Amtech FD-148 & RF501C and the DS64 floppy drives. Those seem to be more or less OEM so possibly those brands only existed on paper.

  

For that matter recently a STL file was made available for anyone with a 3D printer to get your own connectors that will fit all those with a bit of DIY. Of course you still need to come up with the dual voltage AC supply. 

Yes that makes sense. In 1983 Spectravideo manufactured their own power supplies using that special 4 pin connector. Then Spectravideo in 1985 must of used the exact same power supply with their business agreement with Blue Chip, and the only thing that was changed on the power supply was the brand name on the label.

 

I have not purchased a 3D printer yet, however I may do so in the future since there is a growing amount of uses for the 3D printers. Where does one find the public domain STL file for the special 4 pin connector?  That is great that someone designed and donated a public domain custom mold for the community. Some USA companies that specialize in power cords would charge up to $8,000 just to design a mold, while of course China is a lot cheaper when it comes to mold designs. Many video game systems use used cartridge shells since new mold designs cost up to $6,000 for a cartridge shell. The ColecoVision is one of the few systems that has a new plastic molds for third party cartridges. The Atari 5200, and Atari 2600 use used cartridge shells. Hopefully with more people getting 3D printers public domain connector molds and cartridge shell molds will become available for many different systems.     

Edited by HDTV1080P

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I just found my SV-328 in a box in the garage after 20 years,  but I haven't yet found the power supply.  All of this  information in this thread is very good, but I've been having a look at the schematics of the SV-328 and it looks like you don't necessarily need two AC voltages.  The 8VAC feeds into a full wave bridge rectifier and then into a 7805 regulator, this means that circuit should work with any 1.5 Amp supply either AC or DC  between 7-10V.  The 16VAC feeds into two half-wave rectifiers, one for +12V, the other for -12V so you still need an AC signal.  I should have a spare TI transformer around,  it looks like you might be able to rewire it to work with the Spectravideo.  I'll have to experiment a bit when I get the chance.

Edited by mutterminder
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But if you have an old PC power supply that does both +12V and -12V, could you bypass the rectifier? Of course it depends how many amp you need on the -12V. Up to 0.8A might be too much even for beefy PC AT power supplies.

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If we are going to open up the possibility of internal modifications to the SV-328, this would give us plenty more options.  I was just considering plug and play options for a stock SV-328.  Even though the TI-99/4A power brick has both 18VAC and 8.5VAC which is close enough to what we need,  there are only 3 conductors in the plug so we can't really use it.  Plus the 8.5VAC probably can't deliver enough current for the 5V regulator in the SV-328.  I'd like to investigate whether the Colecovison power supply could be modified for the purpose, but I can't seem to find a schematic of it.

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The Colecovision power supply outputs DC voltages through the same connector, so it is an even worse match.

 

The 3rd party floppy drives I mentioned above are perfect matches for Spectravideo, and even tend to come with PSU's manufactured by Spectravideo...

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