Coleco ADAM Ram Expansion and Tape Drive Repair

[Atariman]

That would be great. My wheel is locked up as well. Did you by any chance record the color pattern of the connectors on the circuit boards? Shoot me an email to paul_severini@hotmail.com and I'll send you over my address if you still have a piece of that rubber tubing. I just got the drive apart and I'm basically at the point where I need to remove the black box with the two small screws. What should I expect when I get into that area? Should I use alcohol to clean the black stuff up?

 

I didn't record the color pattern on the PCBs, but I can take a picture and send it to you. I've got *gobs* of rubber tubing when you consider how little is required to fix this. I'll send you some for free if I can find it. I'll see what I can come up with for you.

[pseverini]

Thanks. Let me know if you find any.

 

Questions:

 

Does the Saturn like encoder disc stay attached to the back of the main wheel shaft? I also have some other part behind this so called-encoder disc that looks like a silver rectangle with rounded top corners and a small peep hole. Did you apply any lubricant between the encoder disc and the silver colored rectangular item? It seems like they run on top of each other when the wheel spins. I had tons of black gunk between them and I had to pry them apart by soaking them in rubbing alcohol. I'm finally starting to see how the opto-encoder works with the small hole in the rectangular piece. BTW...I have two small washers and I'm going to assume that I should put one on each end of the wheel shaft (axle). Is that correct?

 

I'm not sure how much give or take there's going to be with aligning the peep hole to the encoder disc once I try to assemble everything back together. The rubbing alcohol seems to a good job if you let the silver parts soak for a while.

[Atariman]

Thanks. Let me know if you find any.

 

Questions:

 

Does the Saturn like encoder disc stay attached to the back of the main wheel shaft? I also have some other part behind this so called-encoder disc that looks like a silver rectangle with rounded top corners and a small peep hole. Did you apply any lubricant between the encoder disc and the silver colored rectangular item? It seems like they run on top of each other when the wheel spins. I had tons of black gunk between them and I had to pry them apart by soaking them in rubbing alcohol. I'm finally starting to see how the opto-encoder works with the small hole in the rectangular piece. BTW...I have two small washers and I'm going to assume that I should put one on each end of the wheel shaft (axle). Is that correct?

 

I'm not sure how much give or take there's going to be with aligning the peep hole to the encoder disc once I try to assemble everything back together. The rubbing alcohol seems to a good job if you let the silver parts soak for a while.

 

Honestly, I think you're on the right track. I actually peeled the disc off of the back of the shaft, cleaned everything thoroughly, and then used some super glue to reattach it. I cleaned all of the gunk out and didn't even bother with any lubricant - and you're right, the two pieces do go on top of one another. (I soaked them in rubbing alcohol as well) I don't totally remember where the washers go, but I think that sounds right. I'll see what I can find out.

 

If you don't hear from me soon, feel free to PM me as it may have slipped my mind. Sometimes I need a nudge.

[pseverini]

There are two flavors of the Viton tubing on the McMaster-Carr web site. Do you know which one you purchased? Soft or Firm?

 

Thanks.

 

Durometer Type Per Foot

Opaque Black Color

60A (Soft) High-Temperature Soft Viton® Fluoroelastomer Rubber Tubing 5119K45 1-49 Ft. $8.33/ft

 

75A (Firm) High-Temperature Firm Viton® Fluoroelastomer Rubber Tubing 5119K15 1-49 Ft. $7.45/ft

[Atariman]

I got this stuff here:

 

Viton High Performance Synthetic Rubber Tubing Type B, 3/8" ID x 1/2" OD x 1/16" W

 

EDIT: (I believe the stuff I mentioned is the 75A)

Edited August 3, 2009 by Atariman

[pseverini]

Did you find that tubing by any chance? Thanks.

[Atariman]

Unfortunately, none of my searches have turned up anything. I can't help but feel like it wasn't that long ago that I saw it, but I just can't seem to find it. (I even found the BOX it came in! Argh!)

 

Could you take a picture of the part you need to see assembled? I know *exactly* where my ADAM is (it's in its gigantic box that hulks in the corner of my living room), so I should be able to take a picture of what you need. If I come across the tubing anytime soon, I'll let you know for sure.

[ValkerieSilk]

I've heard more than a few people talk about having a Digital Data Drive that will run a tape all the way to the end, then start making a clunking noise, while never loading a program. The case for most is that the little rubber pinch roller wheel is missing. The aluminum hub is still present and spinnable, but the rubber outter wheel is gone. I've got one of these problemed drives myself so I thought since it already doesn't work, I'm not too afraid of screwing it up. On a starndard audio cassette deck this pinch roller is nothing more than a spinning wheel which the tape rides on. In the ADAM drives, this wheel is actually an encoder within the housing. Much like how the Steering Wheel Module and Roller Controller turn the pulses from a sloted disc into on-screen motion, this slotted disc must somehow use the pulses it counts to control where the tape starts and stops and the likes. So if there is no rubber wheel present for the moving tape to make contact with, which in turn would spin the encoder disc, the ADAM has no idea how far the tape has reeled and that's why it runs to the end. I measured the ID and OD of the rubber wheel on one of my good drives and I've got some replacement material on the way. With any luck this will be a fix for all of those non-functioning Digital Data Drives you've all got lying around.

 

 

This is exactly the problem I am having and I am so happy to have read your solution. Thank you so much for posting this information. I’m going to give your solution a shot hopefully this week and I’ll post my results. I have another ADAM I purchased off Ebay (where else) that supposedly has a functioning data drive, so I’ll have something to compare it to. I’ll try and post some pics of your repair process as I go through it.

[ValkerieSilk]

I've heard more than a few people talk about having a Digital Data Drive that will run a tape all the way to the end, then start making a clunking noise, while never loading a program. The case for most is that the little rubber pinch roller wheel is missing. The aluminum hub is still present and spinnable, but the rubber outter wheel is gone. I've got one of these problemed drives myself so I thought since it already doesn't work, I'm not too afraid of screwing it up. On a starndard audio cassette deck this pinch roller is nothing more than a spinning wheel which the tape rides on. In the ADAM drives, this wheel is actually an encoder within the housing. Much like how the Steering Wheel Module and Roller Controller turn the pulses from a sloted disc into on-screen motion, this slotted disc must somehow use the pulses it counts to control where the tape starts and stops and the likes. So if there is no rubber wheel present for the moving tape to make contact with, which in turn would spin the encoder disc, the ADAM has no idea how far the tape has reeled and that's why it runs to the end. I measured the ID and OD of the rubber wheel on one of my good drives and I've got some replacement material on the way. With any luck this will be a fix for all of those non-functioning Digital Data Drives you've all got lying around.

 

 

This is exactly the problem I am having and I am so happy to have read your solution. Thank you so much for posting this information. I’m going to give your solution a shot hopefully this week and I’ll post my results. I have another ADAM I purchased off Ebay (where else) that supposedly has a functioning data drive, so I’ll have something to compare it to. I’ll try and post some pics of your repair process as I go through it.

 

 

Well, I tried the fix, took a lot of pictures, but destroyed the encoder disk while cleaning it… Be careful with the encoder disk as the thin metal prongs will bend easily. Also, I ran into two very very small metal washers that I have no idea where they came out of? If anyone wants the pics, email me @ scleme@prodigy.net and will provide them… Also, if anyone has a spare encoder disk that would be great.

[CPUWIZ]

Just noticed this thread. I got a NIB Adam RAM expansion module in my closet, if anyone wants to make an offer, feel free.

[scouter3d]

Thank you so much for the Data Drive Fix!

 

My Colecovision Expansion Pack #3 (Coleco Adam) had exactly this Fault! (Tape was very fast wound to the end and then clicking Noise)

and i was wandering what that little metalwheel was doing ...

So i dismantled the Datadrive and pulled out the little Indexwheel (as mentioned above in an other post, yes!!!! the Indexdisk is very sensitive so i was really careful, i used a cotton-ear-stick to clean the Disk. I measured the diameter of the metalwheel and it was exactly 10mm the Should be outer-diameter with the rubber attached should be 3/8 Zoll (from other post above) (i calculated about 13mm). So i went to the local Hardwarestore "Bauhaus" and in the Gas/Water Plumbing Installation Area i found a "Quetschverbinder" made of Rubber with exactly the right dimensions 10x13x4mm. 2 Pieces for 0,7 Euro.

I attached the Rubber to the Wheel put the Drive together and Voila! Buck Rogers was loading!!!!!

 

So again thank you very much!!!

 

To everyone whose Drive is not looking like the attached Pic, and there is only a Metalwheel instead of a "Rubberwheel", try this Fix!!!!!!

 

Greetings from Vienna TOM:-)

[soviet]

I like to know if pictures of how the ram chips look after installation can by posted, it could by easy to do the mod having this as reference.

Also where i can buy the ram chips ?

 

[NIAD]

Seeing as DoubleDown hasn't been around since 2009 and he is the only one that has performed this RAM Mod, pictures are no where to be had. If you prefer to perform this Mod, then follow the instructions in the E.C.N. article that is linked by DoubleDown and I would assume you would be best served to use the same RAM Chips that you find present on the ADAM Logic Board. IIRC they are something like TMS4464-15 or TMS4164-15, but double check this yourself when you open up the system and FYI the ADAM Logic Board is the bottom board in the Stand-Alone Memory Console and the only board in the Exp. Mod. #3 Memory Console.

 

FWIW, I would send ADAMcon a PM as he usually has some memory expanders available and a decent price and it takes a couple seconds to open the lid on the Memory Console and insert the M.E. into Slot #3... compared to the time and expense (8 ram chips plus shipping) needed to invest in this mod. I would ask ADAMcon if he has a M.E. with sockets installed on the board for the RAM and Logic Chips seeing as you can then more easily replace them if one of the chips goes bad. If you perform the mod and a chip or chips go bad, there will be a lot more work involved.

 

If you are interested, I have such a 64K Memory Expander with extra RAM and Logic chips that is not working (I think a bad solder joint or trace) that I will let you have for $10 plus shipping. Sorry for the sales pitch, I just remembered I had it and would like to see someone with the ability fix and then put it to good use.

[JamesD]

Try this site for RAM chips:

http://www.arcadechips.com/

[JamesD]

Or this site:

https://www.twistywristarcade.com/

[soviet]

Great james thanks !.

[TripHammer]

I also damaged my little encoder wheel. Any one have any ideas where I can get a replaement part?

[adamcon]

I also damaged my little encoder wheel. Any one have any ideas where I can get a replaement part?

ADAM's House has "dead" data drives. You could ask for one with a free spinning timing wheel and good tire, then take it apart for the timing wheel unit. Will cost you about $20, but you can't find them any other way except by buying a dead one with a good wheel

[TripHammer]

ADAM's House has "dead" data drives. You could ask for one with a free spinning timing wheel and good tire, then take it apart for the timing wheel unit. Will cost you about $20, but you can't find them any other way except by buying a dead one with a good wheel

Adam's House? Can you provide a link please? Thanks.

[adamcon]

Adam's House? Can you provide a link please? Thanks.

http://coleco.freeservers.com/proddes.htm and scroll down to the data drives. Terry is not inexpensive, BUT where ya gonna get parts, unless you can get untested one on Ebay and buy it. Hopefully, you can request and get a bad drive with a good spinning wheel with good tire. GOOD LUCK

[NIAD]

The link to ADAM's House (now known as eColeco) is coming up as forbidden, try this one:

 

http://www.ecoleco.com/

[TripHammer]

The link to ADAM's House (now known as eColeco) is coming up as forbidden, try this one:

 

http://www.ecoleco.com/

Thanks, Ordered one and it should be here in a few days. $16 and change with shipping isn't too bad of a deal and I'll hopefully have plenty of spare parts in the process.

 

Thanks All!

[Milli V]

This is an old thread but a popular one on Google so I thought I would add that I repair the drive wheels and also have a video on how to do it if you want:

 

http://retrosystemrescue.com/product/data-drive-index-wheel-repair/

[Mike Harris]

I know this is an old thread but if anyone out there has the knowledge can you use TMS4164-15NL instead of TMS4164-20NL ram chips.

It seems everyone on EBAY is screaming vintage again and overpricing these.

And the 15NL's are reasonable.

[soviet]

36 minutes ago, Mike Harris said:

I know this is an old thread but if anyone out there has the knowledge can you use TMS4164-15NL instead of TMS4164-20NL ram chips.

It seems everyone on EBAY is screaming vintage again and overpricing these.

And the 15NL's are reasonable.

Mike the 15NL chips will work solder sockets first so you can replace them easy in the future the only difference between the 15NL and the 20NL is that they are faster so no problem.