Hardware Questions for the Creator of the Colecovision?

[AguyinarRPG]

Hello all. Over the past few months I've been speaking with the original hardware designer of the Colecovision. No, it's not Eric Bromley (nor has he claimed that title) and I will be making the interview public at his request when we finish.

 

What I wanted to ask of the community is if there are any particular mysteries about the Colecovision hardware that may want to be solved. I am not an extremely technical person but I have done the best that I can in coming up with questions about the hardware. I have seen a few proposed theories about certain aspects of the Colecovision's design so I want to open it up to those who may be more knowledgeable about the subject to submit some questions.

 

He was largely a hardware guy (though he wrote the OS) so asking him about the games is not going to yield much in the way of perspective. If the community has any mysteries on a nuts and bolts level that they're dying to know about, please submit them in the thread. At the conclusion of this interview I should hopefully have even more amazing stuff to share with you beyond the story, but again keeping that under wraps for now.

 

Thanks all!

[NIAD]

Looking forward to the release of the interview. Thanks for sharing it when completed.

 

I've read Eric Bromley's interview that was in a retrogaming magazine about 7 years ago and thoroughly enjoyed it. Aside from that, could you ask him:

 

-At what stage the CV was at before Nuvatec made their contributions and where there any further changes by Coleco personal after Nuvatec's design changes/additions.

 

- There were numerous Revisions to the CV PCB. Does he recall or still have information pertaining to these Revisions especially seeing as Homebrewers are really pushing the limits of the system know-a-days and there have been some issues that have arisen... although some of these might be related to modded systems.

[Ikrananka]

Wow - can't wait to read the interview

 

I have a couple of questions:

• There are often complaints about the ColecoVision joysticks being awful (personally I don't mind them apart from the hand cramps they can generate). Now, we know that there were prototype joysticks that including a spinner, but I'm curious to know what earlier concepts for the joysticks were considered and what the decision making process was that led to the one's that were released.
• The size and weight of the power brick is something that stands out with the ColecoVision. Was this ever considered to be of concern when designing the system?

[Ikrananka]

I've read Eric Bromley's interview that was in a retrogaming magazine about 7 years ago and thoroughly enjoyed it. Aside from that, could you ask him:

 

Just in case anyone is looking for this interview, it was published in the UK "Retro Gamer" magazine, Issue 73 from Feb 2010.

[tschak909]

Why were there so many similar system designs in the same time period? ColecoVision, MSX, Sega SG-1000, Hanimex Pencil II, etc, all had Z80, TMS9918, (and what amounted to the TMS9919, can never remember its name), but all at different I/O and memory maps. Were you looking at a reference design?

 

-Thom

[+nanochess]

Cool! I've some questions also:

 

* Why the cartridge port has so few pins, some extra lines would have been great. (RD/WR)

* The reason to insert a wait state in M1 like in MSX, memory was fast enough already.

* Has been planned to change to TMS9118 using only 2 memories?

* Has been planned to expand the internal RAM from 1K? (6116 RAM with 2K could have been a good option)

* Has been planned to make a 5V+ only system?

* Who choose the awkward power connector where wires can break loose and not able to be soldered again.

* Who designed the controller ports and the reason to not include protection for static discharges.

* Has been planned to include a second SN76489?

* Do you have still original PCB blueprints?

* Do you have still original Colecovision schematics?

* Do you have still original source code to Coleco BIOS or preliminary versions?

* There were other prototype Colecovision before the purple box ones?

 

Thanks!

[AguyinarRPG]

Thanks everybody! I will continue to check the thread for questions but these are all great! I knew I came to the right place.

[Hannacek]

I think a lot of these questions about the power brick, controller ports, and power connector are just manufacturing choices to save money.

[The Evener]

Was the hardware designer directly involved in discussions about the system's expansion options? ColecoVision put the expansion module interface front and centre and it was a clear market differentiator. How large did these expansion options loom in the final design of the system?

 

More specifically, I'm curious about the early discussions around the Super Game Module and the computer expansion (later ADAM). As others have pointed out, both expansion options were referenced in early Coleco promotions together but these products also compete against one another. Was the designer privy to early discussions about how these expansion options would co-exist, or was Coleco simply covering all of the marketing angles until they had more time to see where the market was going?

Edited August 21, 2018 by The Evener

[retroillucid]

Wow, awesome!
Could you ask him these questions?

 

- What is the story behind the Purple box system?

 

- Why have they decided to remove the spinner from the original controller? (to market the SA Controller?)

 

- Any ideas what happened to those lost SuperGame Wafer games?

 

- What do you think of the Colecovision homebrew community? (new games etc.)

Edited August 21, 2018 by retroillucid

[Tony Cruise]

It would be most interesting to find out more about the ties with Spectravideo, from what others (from Coleco and Spectravideo) have said there was some technology transfer one way or another.

We know MSX came from the Spectravideo base hardware and we also know that Colecovision and Spectravideo had fairly close ties. But there is a not a lot of public detail on what was exchanged.

The discussions may have only been so Spectravideo could bring out their Colecovision adapter.

[AguyinarRPG]

-At what stage the CV was at before Nuvatec made their contributions and where there any further changes by Coleco personal after Nuvatec's design changes/additions.

What do you mean by this? As far as I know Nuvatec was just a software developer. Do you have reason to believe they altered parts of the Colecovision design?

 

* The reason to insert a wait state in M1 like in MSX, memory was fast enough already.

* Has been planned to change to TMS9118 using only 2 memories?

* Has been planned to include a second SN76489?

I am not quite sure what these questions are asking.

 

It would be most interesting to find out more about the ties with Spectravideo, from what others (from Coleco and Spectravideo) have said there was some technology transfer one way or another.

We know MSX came from the Spectravideo base hardware and we also know that Colecovision and Spectravideo had fairly close ties. But there is a not a lot of public detail on what was exchanged.

The discussions may have only been so Spectravideo could bring out their Colecovision adapter.

Do you have any particular sourcing on this? Closest I could find was an admission by Arnold Greenberg that they may become involved in the MSX standard, which of course was based on the Spectravision. What's the reason to suspect that Spectravideo had some sort of deal rather than just ripping Coleco off?

[Tony Cruise]

What do you mean by this? As far as I know Nuvatec was just a software developer. Do you have reason to believe they altered parts of the Colecovision design?

 

I am not quite sure what these questions are asking.

 

Do you have any particular sourcing on this? Closest I could find was an admission by Arnold Greenberg that they may become involved in the MSX standard, which of course was based on the Spectravision. What's the reason to suspect that Spectravideo had some sort of deal rather than just ripping Coleco off?

From an interview with Harry Fox (Spectravideo), plus the known long development time of the Spectravideo design, how it was shown around a lot of companies (mainly in Japan) by Nishi from ASCII Corporation, well before the actual MSX standard was formed. Spectravideo released most of the titles they developed for the Spectravideo for the Colecovision as well, plus also bringing out the Colecovision adapter (which has Colecovision branding on it - there had to be some discussion).

So really was there any design leakage either way or at least any more information on timelines would be fantastic.

There is a rumor (and only a rumor) of Spectravideo selling an early design to Colecovision to assist with memory timing issues they were having. This could be completely false, or even around the other way, but it would be nice to get some more information closer to the source.

Plus the even more mysterious why the SG-1000 hardware is even closer to the Colecovision design.

[youki]

Plus the even more mysterious why the SG-1000 hardware is even closer to the Colecovision design.

 

My theory for having so much machines sharing the same kind of hardware at this time. Is , if you were a manufacturer at this time willing to create a machine at reasonable cost with out of shelves component (not using custom chip) , there are strong chance that you reach similar hardware design at the end , even if you don't look at the others.

 

there is not so much combination to assemble a Processor , a VDP , sound chip and RAM. Except some port number affectation , Ram quantity , and if you choose to have a BIOS or Not.

 

I think the VDP was the most cost/power effective at this time. So lot of company choose it naturally Then, still considering cost, you have the choice with a Z80 or 6502 . Most went to the Z80 , except the Creativision that used a 6502 (the Creativation is fact no more than a Colecovision with 6502 ).

[mr_me]

Ask if they considered a design with less video ram, e.g. 4kB, to get to market sooner.

 

When did they first come up with the joystick design? Did they get any joystick ideas from the apf-mp1000 or others.

 

Does he know anything about a video game system coleco sold to mattel.

Edited August 22, 2018 by mr_me

[NIAD]

AguyinarRPG.... Nuvatec also developed hardware, but yes, they were better kniwn for their software development including the first ever ColecoVision game, Cosmic Avenger.

 

As far as everything I have read/heard from Coleco sources, Nuvatec was behind the addition of the Expansion Bus (which started the ball rolling re. a computer expansion for the CV) and solved some other issues that Coleco R&D was having.

 

Also wondering who was behind the decision to remove the Speed Roller on the early Hand Controller? Was it a Marketing call in order to add another unique feature to the Super Action Controller?

[youki]

You could also may be ask , if he knows something about the Intellivision Expansion Module ?

[atarilovesyou]

Here's an easy one:

 

Why were so few games made to take advantage of the special controllers like the steering wheel and trackball, especially considering the huge costs involved in developing those controllers?

[AguyinarRPG]

From an interview with Harry Fox (Spectravideo)

Do you have said interview so I can check the context of it? This is something I'm interested in more generally even if I don't think the hardware designer can answer the question. A friend of mine has talked to, and plans to again, Arnold Greenberg so it would be good to get some context on that front.

[Tempest]

Here's an easy one:

 

Why were so few games made to take advantage of the special controllers like the steering wheel and trackball, especially considering the huge costs involved in developing those controllers?

My guess would be because they didn't sell well enough to justify more games. Sort of like what happened with the Intellivoice. People didn't want to buy extra add-ons.

[Hannacek]

My guess would be because they didn't sell well enough to justify more games. Sort of like what happened with the Intellivoice. People didn't want to buy extra add-ons.

 

Each of the extra controllers had 4 or 5 games made for them, plus they could work with any regular game. It looks like they intentionally made the minimum number of games as to not make people feel they wasted money on the extra controllers.

 

This is a classic problem of attachments for consoles. Look at the NES gun, how many games were made for that? Maybe around 20, most in the first year or two of the console. What about the Kinect for Xbox One? Very few games were made for those 2 attachments, which came bundled with the systems, meaning everyone had the attachment, and was a potential customer. When everyone has the attachment and is a potential customer, it is difficult to develop and sell games for attachments. When only a small percentage of console owners have the attachment like with ColecoVision, it is almost impossible to sell enough games to justify the development of games for those attachments.

 

Only two games were made for the NES power glove. Only one game Super Glove Ball really takes advantage of the glove. There are countless examples of this.

Edited August 22, 2018 by Hannacek

[Tempest]

 

Only two games were made for the NES power glove. Only one game Super Glove Ball really takes advantage of the glove. There are countless examples of this.

 

Dont forget ROB. Only two games for him too.

[NIAD]

Here's an easy one:

 

Why were so few games made to take advantage of the special controllers like the steering wheel and trackball, especially considering the huge costs involved in developing those controllers?

I wouldn't say that they didn't sell well enough especially after seeing SO many in people's collections and for sale over the years on numerous sites such as eBay.

 

I would put the reason that each controller only had 3 or 4 games made specifically for use with them squareley on the ADAM's development and production overwhelming the electronics division at Coleco from early '83 until mid '84.

[+nanochess]

 

* The reason to insert a wait state in M1 like in MSX, memory was fast enough already.

* Has been planned to change to TMS9118 using only 2 memories?

* Has been planned to include a second SN76489?

I am not quite sure what these questions are asking.

 

Given you're talking with the hardware designer of the Colecovision, these are very interesting questions, let me

explain in more detail.

 

* The reason to insert a wait state in M1 like in MSX, memory was fast enough already.

The Z80 processor issues a M1 cycle for each instruction read. In the Colecovision there is hardware to insert

an additional WAIT state each time a M1 cycle is generated. Removing this small hardware would have speed up the

Colecovision by 20%.

 

* Has been planned to change to TMS9118 using only 2 memories?

The TMS9118 is a replacement for the TMS9918 that only uses 2 VRAM memories (instead of the original 8 memories) and

also uses only 5V+ power.

 

* Has been planned to include a second SN76489?

Arcade games are known for having multiple sound chips. Given the Colecovision implemented arcade games, it could have

been considered to implement a second SN76489 without too much difficulty.

 

Hope this helps.

[Swami]

If the first version sold worked, why were some ten revisions of the motherboard made over three years? Some of the reason is availability of parts, but I'm wondering what more there is to it.

 

After all the light gun Coleco Telstar consoles that preceded the ColecoVision, was a light gun considered for the ColecoVision or did they see a drop in interest during the Telstar run and not include it? The Telstar shooting games were pretty basic in nature, but Colecovision could have had a lot more variation, relatively speaking (e.g., it could have beat the NES to Duck Hunt).