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

[mutterminder]

I know that the Colecovision supply outputs DC voltages, however it does have a transformer, and therefore there are internal AC voltages.  I was hoping that I could rewire the output of the transformer directly to the output of the power supply.  Based on the current rating of the DC voltages, the transformer probably isn't beefy enough, but I thought it was worth looking into.  I would gladly use those floppy disk supplies you mentioned, however I don't have one, and they don't seem to be commonly available.  Does anybody have a schematic of the Colecovision power supply?

[carlsson]

Aha, now I understand what you're trying to accomplish. If it wasn't for the connector, I believe the internal transformer of e.g. a 1541 has enough volts and amps for this purpose but that would be a two step process to combine an orphaned transformer with an orphaned connector.

[HDTV1080P]

Back in the 80’s there was over 2 million ColecoVision’s sold, over 3 million Texas Instruments TI-99 series computers sold, and an estimated 100,000+ Spectravideo systems sold. Plus, maybe 50,000+ Blue Chip Commodore disk drives sold. That is an estimated 5.2 million systems made. However, over the many decades out of the 5.2 million systems made, only around 1% of those systems are still being used. So, an estimated 52,000 people out of the 5.2 million systems made are still using those systems in theory. So, if 52,000 people are still using those systems, then there will come a time when they will need a replacement power supply that requires a special 4 pin power connector.

 

Some company should have came out with a custom 4 pin power connector 20 years ago when the demand was a little stronger. I guess they say better late then never. Perhaps no one wanted to take the business risk of making a new expensive custom 4 pin power plug and cable mold for classic 80's systems that are not being made anymore. One never knows what the real world demand is for a product until the product is released into the real world. Some consumer electronic products are very popular when released, other products are not successful at all and end up being products that lose a lot of money.      

Edited December 31, 2019 by HDTV1080P

[HDTV1080P]

On December 23^rd 2019 a new high-end Power cable was released and a QTY of 500 are available on Amazon’s and EBAY’s website

 

Instead of creating a basic low-quality custom power cable and connector mold at half the manufacturing cost, a decision was made to make this classic 80’s style power cable with the best possible materials and manufacturing quality, so that this 21^st Century custom power cable would be the best that has ever been made. According to the EBAY website if one purchases the 20 pack they can get the cable delivered at the manufacturing cost plus 0% markup.

 

*** This high-end top of the line 21^st Century power cable is much better quality when compared to the original 20^th Century power cables provided by Blue Chip, Coleco, Spectravideo, and Texas Instruments.  ***

 

 

 

**** Important info: This is a power cable only; a skilled technician needs to interface the power cable to a compatible power supply or compatible transformer in order to provide power with the following Computer and videogame systems.  **** 

 

 

100% compatible high-end power cable for use with the following computer and videogame systems

·      Blue Chip Commodore compatible disk drives

·      ColecoVision videogame system

·      Spectravideo 318 and 328 computer systems

·      Texas Instruments TI-99 series computers (Texas Instruments model numbers TI-99/4, TI-99/4A, and TI-99/4A QI). 

 

Questions and Answers

 

 

Question: What is the purpose of this power cable? 

Answer: This top of the line power cable is used by skilled technicians as a wire harness. With this power cable (wire harness) it allows a skilled technician to interface a compatible power supply or compatible transformer with the following classic 80’s systems: Blue Chip Commodore compatible disk drives, ColecoVision videogame system, Spectravideo 318 and 328 computer systems, and the Texas Instruments TI-99 series computers (Texas Instruments model numbers TI-99/4, TI-99/4A, and TI-99/4A QI). 

 

 

Question: What is the quality of this power cable when compared to the original ones used back in the 80’s? 

Answer: This 21^st Century power cable is much better quality when compared to the original 20^th Century power cables provided by Blue Chip, Coleco, Spectravideo, and Texas Instruments. This power cable was engineered in the United States and made in China using high quality materials with the help of automated machines. The original 80’s power cables were unshielded, did not use gold plating, used around 20 gauge thinner wires instead of the thicker 18 gauge wire, and did not have any Ferrite Beads. This new 21^st Century power cable has a custom molded 4 pin plug with a total of 4 3u Gold-Plated pins. The other end of the power cable has a custom molded tail part with 18 gauge stripped and tinned wires. This 18-gauge power cable uses a high quality dual shielded PVC jacket. Both a single sided Aluminum Foil Shield and a Braid Shield. Also, this power cable has two Ferrite Beads to eliminate or reduce EMI/RFI interference bi-directionally from both ends of the cable (One black Ferrite Bead next to the molded 4 pin plug and one next to the molded tail part). This new 21^st Century power cable is top of the line and can handle up to 300 Volts and is designed to last several decades.    

 

 

Power cable Specifications

 

100% compatible high-end power cable for use with the Blue Chip Commodore compatible disk drives, ColecoVision videogame system, Spectravideo 318 and 328 computer systems, and the Texas Instruments TI-99 series computers (Texas Instruments model numbers TI-99/4, TI-99/4A, and TI-99/4A QI). This is a power cable only; a skilled technician needs to interface the power cable to a compatible power supply or compatible transformer in order to provide power with the above Computer and videogame systems.

 

 

• Power cable was engineered in the United States and made in China using high quality materials with the help of automated machines. 

• High-quality custom molded 4 pin plug is Gold Plated and is designed to last several decades (Gold Plating provides corrosion resistance). 

• This high-quality Power cable is ROHS compliant and is made with UL approved material.

• Power cable length end to end is 6.56 feet (200CM).

• One end of Power cable has a custom molded 4 pin plug with a total of 4 3u Gold-Plated pins. The other end of the power cable has a custom molded tail part with 18 gauge stripped and tinned wires.

• This 18 gauge power cable uses a high quality dual shielded PVC jacket. Both a single sided Aluminum Foil Shield and a Braid Shield.

• Power cable has two Ferrite Beads to eliminate or reduce EMI/RFI interference bi-directionally from both ends of the cable (One black Ferrite Bead next to the molded 4 pin plug and one next to the molded tail part).

 

 

Wire Specifications

 

 

Conductor: UL2464 18 gauge x 4 tinned copper wires + 1 black color wire that is the shield. Strands 16/0 .254+/-0.008mm. 20 degrees C, resistance maximum 23.2 ohm/KM.

 

Insulation: PVC insulation thickness NOM: 0.38mm, MIN: 0.28mm, Rated 80 degrees C, 300 Volts, Insulation Over Diameter: 1.98 +/- 0.10mm, Color: Yellow, Red, Blue, White, and Black for the shield.

 

Dual Shielding specs: This 18 gauge power cable uses a high quality dual shielded PVC jacket. Both a single sided Aluminum Foil Shield and a Braid Shield (16/6/0. 10TS+/-0.008mm).

 

Jacket: PVC Jacket, Average Jacket Thickness: Nom: 0.76mm, MIN: 0.60mm, Rated: 80 degrees C, 300 Volts, Cable Over Diameter: 7.00 +/-0.30mm, Color Black.

 

Markings: E332295, AWN STYLE 2464 18AWG, 80 degrees C, 300V, VW-1 PVC, FT1 -LF-.   

 

 

Edited December 31, 2019 by HDTV1080P

[carlsson]

So $25 + international shipping, or $13/ea if you buy 20 cables.

[HDTV1080P]

18 hours ago, carlsson said:

So $25 + international shipping, or $13/ea if you buy 20 cables.

Those are EBAY and Amazon prices which includes free domestic shipping in the USA. The cable is available for shipping International on EBAY’s and the Amazon’s website. EBAY has a Global International shipping program where the EBAY dealer ships the package to EBAY’s International shipping center in Kentucky and EBAY sets the cost of International shipping based on the weight of the package and based on which country it is going to.   

[mutterminder]

Okay guys,  I got one of these cables.  I must say they are very high quality, however $25 is a bit pricey.  Anyway  I have a couple of Billion power supplies, which are third party after market power supplies for the Commodore 64.  These are much easier to open than genuine Commodore supplies as there are just four screws holding it together.  I've attached a few pictures showing the internals of this supply which just has a single sided PCB with a 5V regulator.  I measured the 9VAC output at about 10.4VAC.  For the 5 Volts  there are a couple of rectifier diodes, and a filter cap feeding the regulator.  With the rectifier diodes lifted,  I read about 15.1VAC coming out of that transformer winding.

 

 

The  yellow and white wires are the "9VAC".  The black and red wires are 5VDC.

 

Here the red and yellow wires are on the 10.4VAC,  I had to drill these holes just a bit bigger to fit the heavier gauge wires.  I've lifted the rectifier diodes, unsoldered the regulator leads and bent them up, and connected the white and blue wires to the 15.1VAC here. The black shield wire is connected to ground.

 

Notice in the last two pictures that the strain relief fits almost perfectly in this case thought I had to cut away just a little bit of plastic in the top lid to get it to fit.

 

 

Here we see that it seems to work perfectly.  This is the first time I've ever powered up my SVI-328.  The power plug is a very tight fit in the SVI-328,  and I had to use more than the normal amount of force to get it in, but it did seat all the way.  We'll have to see if this is a good permanent solution.  Neither the power supply or the SVI-328 seem to be overheating.  I'll post here, if I run into any issues.

 

 

 

 

Edited March 8, 2020 by mutterminder

[HDTV1080P]

Thanks for posting information about a third party Commodore power supply that you internally modified so that it works with the SVI-328 when a custom power cable wire harness is attached.

[HDTV1080P]

I converted a 550 Watt ATX power supply into a ColecoVision power supply using the high-end custom 4 pin Gold Plated wire harness attached to the ATX power supply. This is my actual first in production power supply using the new high-end Gold plated wire harness (prior power supplies used before were prototype power supplies. Everything went smoothly, better quality then the orginal Coleco 4 pin connector).

 

Here is the link to the 550 watt Smurf ColecoVision power supply.

https://atariage.com/forums/topic/284408-how-to-make-your-own-colecovision-power-supply-that-operates-worldwide/?do=findComment&comment=4556844

Edited June 5, 2020 by HDTV1080P

[HDTV1080P]

Here is a link to a new top of the line ColecoVision Desktop Power supply that became a reality using a new 10 inch Gold Plated wiring harness for the ColecoVision that interfaces with a required energy efficiency level VI power supply.

 

28.5 watt ColecoVision compatible power supply (The best quality PS every made for the ColecoVision)

 

Even though the ColecoVision power supply puts out 3 separate voltage levels from one power supply, since all 3 voltages are DC instead of AC, creating a new power supply for the ColecoVision is easier when compared to computer systems that use AC voltages.

It would be much more difficult to make a power supply for the TI-99 series computers and the Spectravideo 318 and 328 computer systems. The first problem is there is no external power supplies in existence in 2020 that outputs two separate AC voltages and then on top of that issue the external power supply needs to be energy efficiency level VI in order to resale per the Department of Energy law that was put in place back in Feb of 2016. Now it looks like I could in theory get the TI-99 and Spectravideo computer systems to work with two separate AC power supplies that are energy efficiency level VI, however that is a downgrade from the original TI-99 series adapters and Spectravideo adapters that put out two different AC voltage levels from one adapter.    

 

I really would prefer a entirely new desktop adapter be created with dual AC voltage levels. However, some power supply companies would want a minimum order of 2,000 power supplies for a new design to be created. Some other smaller power supply companies might accept a minimum order of 500 dual output regulated switching AC power supplies that are energy efficiency level VI.   

 

All this stuff is time consuming and it might be idea to take a break in a few days and watch some Blu-ray discs.

[HDTV1080P]

In the 21^st Century we have regulated DC power supplies that are better quality when compared to unregulated DC power supplies found on some computer and videogame systems in the 1970’s, 1980’s, and 1990’s. Also, in the 21^st Century all modern DC power supplies accept an input voltage between 100-240 volts AC at 50/60Hz. All current modern AC power supplies only work on either 120 volts or 220 volts and are not dual voltage for worldwide use.

 

It would be possible to create a new state of the art power supply for the TI-99 series computers and the Spectravideo 318 and 328 computer systems

 

AC power supplies are harder to find and they also are much more complicated when compared to DC power supplies. The best UL listed AC power supplies offered for the consumer market in 2020 are all single voltage output transformers that also have the required level VI DOE rating. However even in the year 2020 the best AC power supplies are unregulated and drop in voltage as the amp draw from the device increases. There is no modern off the shelf AC power supply that will work with the TI-99 series computers and Spectravideo 318 and 328 computer systems. I believe I can use two separate power supplies like a 16 volts AC power supply and a second 9 volts AC power supply connected to the special wire harness, and since its level VI approved by the DOE, it should work and would be legal for resell. However, the original TI-99 and Spectravideo computers use a single wall transformer that outputs two separate AC voltages, which is better for the consumer. So even though one can legally sell two wall adapters wired to one wire harness that is level VI, it would be a downgrade compared to what people in the 80’s were using for AC transformers.

 

In the 21^st Century since all or almost all modern electronic products are using low voltage DC voltage, new AC power supplies are not in demand. Therefore, companies are not spending the money to do research and development on improving AC wall power supplies and AC desktop power supplies.

 

It is technically possible with research and development to create a new style of AC power supply that could be used for the TI-99 series computers and Spectravideo 318 and 328 computer systems.  

 

Specs that could be done for a new state of the art 21^st Century AC power supply

 

(1)  The new AC power supply would have a regulated 16 volts AC output and a regulated 9 volts or 8 volts AC output. The 16 volts AC and 9 volts AC would remain the same regulated voltage regardless of the current load anywhere between 0 to 3 amps. This would be a major improvement since an unregulated AC power supply today drops in voltage each time the load increases. With a new state of the art regulated AC power supply 16 volts and 9 volts output would occur regardless if the load is 3 amps, 2 amps, 1 amps, 0.5 amps, or 0 amps.  

 

(2)   The dual voltage AC output power supply needs to be able to operate on both 115V 50/60Hz and 230V 50/60Hz and be auto sensing/switching to the applied input voltage between 100-240 volts. And have a detachable 3 pole or 2 pole AC inlet socket that allows one to plug in their own style of country power cord. This is a feature that is only found on DC power supplies, but a similar design could be ported over to a new AC power supply.

 

(3)   The power supply would need to be UL listed, FCC certified/tested, CE safety for Europe, and level VI energy efficiency.

 

I have been in communications with some power supply companies regarding making a custom state of the art AC to AC power supply. While many power supply companies require a minimum order of 2,000 power supplies, I located one company that would take a minimum order of 500 power supplies. However, the estimated research and development cost on a new state of the art AC power supply would cost between $10,000-$15,000+. Then it would cost another $15,000+ for UL listing plus the fees for FCC, CE, and level VI DOE. So, one might be looking at around $30,000+ just to complete the research and development costs with the safety certifications like UL listed. The cheapest UL listed and level VI unregulated AC power supply with single voltage output costs around $20 after shipping. A new state of the art regulated desktop dual output AC power supply might have a list price of around $50. I think I am going to put this project on hold since there is a minimum order of 500 power supplies after one completes the research and development cost. I am not sure there would be enough worldwide demand for such a project. I would rather spend $30,000-$40,000+ on remodeling my home theater setup in the future. Maybe one day I could sell some stocks at a big profit to fund this project or similar projects. Supporting these 70’s, 80’s, and 90’s videogame and computer systems is not profitable.

 

For any power supply project, if one makes a very small change to a existing very cheap AC or DC wall power supply on the market, even if the change does not require any research and development costs, there is a $15,000+ fee just to get the optional UL certification feature on the power supply before it is ran off the assembly line at the factories located in China and other places in the world. That is why some power supply companies when they came out with the new required level VI DOE power supplies back in 2016, decided to make their products only UL recognized material in the specs and decided not to pay $15,000+ to get the product UL listed. So many power supplies online from various websites are no longer UL listed because of the cost involved and instead use UL recognized material which has no fee.

Edited October 10, 2020 by HDTV1080P

[Nelno]

I've posted a project for a power plug / socket replacement I did for my own SV-328 in this forum here.

 

Thanks to everyone who contributed to this thread. It helped me tremendously!

Edited April 29, 2021 by Nelno
Grammar.

[HDTV1080P]

Both Amazon and EBAY dealers have plenty of the 6.56 feet (200CM) custom power supply cables in stock (the one that was released on December 23^rd 2019 in post #29). However, if the day comes where Amazon and EBAY dealers have to reorder this cable. Because of inflation and global supply issues the price would most likely have to be increased by around 20%. However, for now one can still get this cable for $12.99 with free shipping in the USA when ordering in QTY of 20. That is a good deal since that is around the exact same price that Amazon and EBAY dealers paid to get the cable imported into the United States. So the best deal on this cable is when ordering QTY of 20 at a time. I am glad a QTY of 500 were ordered back in 2019, since reordering the cable now would most likely be around 20% higher price and a possibility of not being able to get the cable at all because of global supply issues.

Edited July 15, 2021 by HDTV1080P

[cdoty]

It looks like a defective Commodore 1541 drive power supply could be used.

 

According to the service manual, pins 1 and 4 supply about 16v AC and 2 and 3 supply 9v AC. 

 

http://www.zimmers.net/anonftp/pub/cbm/schematics/drives/new/1541/1540-1541_Disk_Drive_Service_Manual_314002-01_(1985_Nov).pdf

 

An Adrian's Digital Basement video shows the power supply wires with colors that seem to match the pinout. Orange should be 16v AC and purple should be 9v AC.

 

 

I do get 16v AC and 10v AC out of the expected wires.

Edited November 12, 2021 by cdoty

[carlsson]

Yes, I came to the same conclusion a few years ago, but haven't gone ahead and tried it in practice.

[cdoty]

I had a bad 1541, so I gave it a try. It works fine on both the 328 and 728. I don't have a 318 to test. It ran the MSX mapper cart and a normal cart, just find, so I'm guessing there's enough power there.

 

[carlsson]

Yes. Ray Carlsen also suggested this solution many years ago for replacing Blue Chip power supplies, which are identical to Spectravideo power supplies (sometimes the PSU even says Spectravideo on it when it is a Blue Chip floppy drive, go figure).

https://portcommodore.com/rcarlsen/cbm/blue chip/1541 clone/readme.txt

[cdoty]

Yeah, that's where the idea came to try the 1541, since it's more readily available, and broken ones are all over ebay.

[Tonnyrh]

On 10/4/2016 at 12:12 AM, Tempest said:

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.

A Commodore 1541 disk drive has a power with 16 / 9 VAC. Planning to add a plug to one of mine to break out to the SVI

[Luk3]

On 11/24/2018 at 6:28 AM, HDTV1080P said:

...

 

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).

I recently got an SVI-728 without the famous power supply and without any information about its health.

It was impossible for me to find a compatible power supply, after seeing the Spectravideo SV-605 super expander I was convinced that @HDTV1080P solution might actually work, and it did thanks!!

I took an old ATX PSU spare part, 4 wires and a tester, the photos tell it all. I am not responsible for any damage this solution may cause to computers, people or animals.

No external PSU,  no power on/off switch needed ;-)

[HDTV1080P]

Luk3, thanks for trying out my theory. I am glad it worked. Someone could now develop a special cable adapter that plugs into a low cost Mean Well regulated DC power supply, and then AC power supplies are no longer needed for the Spectravideo computer system (But the ATX power supply has a cleaner DC output when compared to most Mean Well power supplies). With a y-adapter the side expansion on the Spectravideo could be used to plug in expansion items also and not just to power the console.

 

In theory someone could also bypass the AC power supply on the TI-99/4A computer and use a +5 volts DC input on pin 1 and -5 volts DC input on pin 43 if the side expansion module specs are correct. Plus there is 12 volts DC on the internal TI-99/4a power supply, but maybe one of those pins also offers 12 volts DC input.

https://allpinouts.org/pinouts/connectors/cartridges_expansions/ti-99-4a-side-port/

 

Just use a low cost regulated DC power supply or ATX power supply that has -5 volts DC and +5 volts DC (+12 volts DC also). Of course this is a theory only and I have not tried it. But there might be many other videogame systems and computer systems that can be powered by the expansion system or even the cartridge port on some systems.

 

Edited January 22, 2023 by HDTV1080P

[HDTV1080P]

I see there is a company now offering a +12 volts DC, -5 volts DC, and +5 volts DC power supply for the TI-99/4a, but the catch is one has to open up and internally bypass the AC to DC power supply, and if one uses the power supply without doing the modifications, the TI-99/4a internal power supply would be destroyed and possible the motherboard.

 

https://www.keelog.com/ti-99-4a-psu-modern-gray-us-replacement-ti-99-4a-power-supply-us-plug/

 

If the side expansion offers bidirectional voltages on the TI-99/4a including +12 volts DC, +5 volts DC, and -5 volts DC, then no internal modification would be needed for the TI-99/4a computer. One would just need to develop a special side expansion cable (maybe a y-cable in order to plug in existing expansion devices). Then a DC power supply to side expansion could be made on the TI-99/4a also.

 

 

Edited January 22, 2023 by HDTV1080P