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A 88 2-SIO board just sold for $396.99, shocking. There's need for replica

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leiy

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Dec 9, 2014
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A 88 2-SIO board just sold for $396.99, quite shocking! There's so many need for 88 2-sio replica.

http://www.ebay.com/itm/281826406119 I'm out bidded..... that's the price far higher than I typed in last 5 minutes.

I wish some Pro can release a MITS 88 2 SIO replication.

Thank you.
 
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Hi All;

Grant, made a really nice 2SIO, I have a couple, and they are just like the original.. If they can be found, as well..
What we need is for Grant to make another bunch of them, along with the rest of the Boards, I could use another CPU Board..

THANK YOU Marty
 
Marty said:
Hi All;

Grant, made a really nice 2SIO, I have a couple, and they are just like the original.. If they can be found, as well..
What we need is for Grant to make another bunch of them, along with the rest of the Boards, I could use another CPU Board..

THANK YOU Marty
Click to expand...

You could also nag him to release the schematics and layouts so we can get our own boards batched up by cheap board houses.
 
Hi All;

Next, I have not been able to get ahold of Grant for many years..
He has not responded to any of my emails..
I can't remember who, but someone on this forum has been able to keep in touch with Him..
I had thought Years ago that we were friends, but, maybe not..

THANK YOU Marty
 
Nama said:
Yes, I have my 3P+S set up as a 2SIO...the only issue being that it's really only a 1SIO, so you can't use http://home.comcast.net/~forbin376/
Click to expand...

It says "...any Motorola 6850 UART based, dual port Serial I/O card addressed at the MITS standard ports of 16 and 18 decimal. .."

I would not want to change my 2SIO to use these ports anyway, I'd rather use something else.

Bill
 
Actually, ports 16 and 18 (decimal) are the standard port addresses for the 2SIO.

The last, and fairly rare, version of the 2SIO used standard IDC connectors in place of the difficult to use (and no longer available) white Molex connectors. Maybe we should recreate this last version.

88-2SIO (new1).jpg

Mike
 
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Not so shocking. This has been about the minimum going rate for a while for a 2SIO. I have also seen Rev-0 SIO-A go for even more.

leiy said:
A 88 2-SIO board just sold for $396.99, quite shocking! There's so many need for 88 2-sio replica.

http://www.ebay.com/itm/281826406119 I'm out bidded..... that's the price far higher than I typed in last 5 minutes.

I wish some Pro can release a MITS 88 2 SIO replication.

Thank you.
Click to expand...
 
Marty said:
Hi All;

Grant, made a really nice 2SIO, I have a couple, and they are just like the original.. If they can be found, as well..
What we need is for Grant to make another bunch of them, along with the rest of the Boards, I could use another CPU Board..

THANK YOU Marty
Click to expand...

That would be great. A couple of years ago I managed to get an order form out of Grant and ordered a couple of 88-2SIO kits but that's as far as it got. Luckily since then I've obtained a real 88-2SIO and a couple of Solid State Music IO4's. But if they were available today I'd buy one just for the fun of building it.
 
leiy said:
A 88 2-SIO board just sold for $396.99, quite shocking! There's so many need for 88 2-sio replica.

http://www.ebay.com/itm/281826406119 I'm out bidded..... that's the price far higher than I typed in last 5 minutes.

I wish some Pro can release a MITS 88 2 SIO replication.

Thank you.
Click to expand...

Jameco has 6850 ACIAs for $5. I bet you could use some GALs to replace the 74XX logic and make a replica no problem.
 
Hi All;

MarsMan, "" I bet you could use some GALs to replace the 74XX logic and make a replica no problem. ""
Once You used Gals to replace the 7400 logic it ISN'T a replica any more..
It's ONLY a replica if You use the same parts as the origional..

THANK YOU Marty
 
I don't care about not being a true replica of not. If I don't have to shell out $100 for an SIO card I'm cool with whatever the design is.
 
You can always wire wrap a compatible board, they're pretty simple and the schematics are available.

Somewhere I've got the (vintage tape-and-film) artwork for SIO-A boards...
 
Hi All;

Glitch, I agree with You completely..
"" Somewhere I've got the (vintage tape-and-film) artwork for SIO-A boards... ""
Where did You get the tape and film, for the Rev A Boards ??

THANK YOU Marty
 
It wouldn't be hard to layout a replica of the original board, or to create an exact functional equivalent of the board using different/newer parts, however, by the time costs are covered for fabricating and assembling a small run of boards, they're going to be in the $100 range anyway. And if they don't all sell, then the hobbyist that created the board doesn't recover their initial cash outlay.

Fabricating and selling just a bare PCB is less of an investment risk, but that reduces the number of hobbyists who can benefit from the board because not everyone wants to buy the parts, build, and then trouble-shoot their assembly.

For a board of this complexity, selling a complete kit is about as much work and investment risk as having the boards assembled in quantity. The bare PCB (and kit) approach also precludes use of a modern SMT part or two that might make a functionally equivalent board simpler and less expensive.

Just my two cents.

Mike
 
I'd have no issues funding a pool for bare boards. Getting the components are easy. It's the PCB's I hate having to get.
 
Marty said:
Where did You get the tape and film, for the Rev A Boards ??
Click to expand...

They were in the lab notes of a hobbyist/engineer/grad student I acquired with some other documentation. No idea if they're *the* SIO-A artworks or if they're for pirate boards where someone didn't just photocopy the original boards. The documentation included artwork for original designs, but I can't find information on who laid out the boards for MITS or much information on the particular engineer whose notes I have. I do know, from his lab journal, that he was a *very* early Altair owner.

Agreed, bare boards are the hard part, for me. I've assembled and tested boards for other people for a fee, and I believe other hobbyists were doing the same with the initial large XT-IDE run years ago, so that's an option for people who can't assemble their own.
 
Marty said:
Hi All;

MarsMan, "" I bet you could use some GALs to replace the 74XX logic and make a replica no problem. ""
Once You used Gals to replace the 7400 logic it ISN'T a replica any more..
It's ONLY a replica if You use the same parts as the origional..

THANK YOU Marty
Click to expand...

I guess it depends on what you want.

If you want a visual replica with the all the original parts, then someone has to scan in an unbuilt board, turn that into a Gerber file with all the drill and via locations, and make new boards. However, MITS was bought out by Pertec which was bought out by Scan-Optics (which still exists) so it's likely that the copyright on the original Altair board designs belongs to Scan-Optics now. *Personally*, I'd not take the risk of duplicating them.

So, assuming the goal is to duplicate the *functionality* of the 88-SIO board so people can add it to their systems and use vintage software - well at that point there's no real reason to limit oneself to using exactly the original parts, just parts that would have register and timing compatibility for the CPU to use and electrical compatibility on the IOs. So why not make the board a little easier to build?
 
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