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OP-80A Paper Tape Reader

D

deramp5113

Veteran Member
Joined
Mar 9, 2013
Messages
969
Location
Dallas, TX
I'm laying out a small PCB to adapt the pinout of the DIP-16 socket used on the OP-80A paper tape reader to the DIP-14 socket used on the Solid State Music IO4 board. This allows connection of the OP-80A to an SSM-IO4 with straight-through ribbon cables (e.g., DIP-16 header to DIP-16 header --> adapter board --> DIP-14 header to DIP-14 header).

The boards are so cheap from China that I can easily get 20 made for the same price as 5, and I doubt I could even give away 19 of these boards for the SSM-IO4 configuration, so I was thinking I might as well add another socket or IDC header onto the board for other common parallel boards people may be using with their OP-80A. Or maybe a patch area and a 24 pin header (2 x 12) that would allow straight through ribbon cables to be used for most any socket from DIP-14 to DIP-24 or even DB-25.

Thoughts?

Mike
 
deramp5113 said:
I'm laying out a small PCB to adapt the pinout of the DIP-16 socket used on the OP-80A paper tape reader to the DIP-14 socket used on the Solid State Music IO4 board. This allows connection of the OP-80A to an SSM-IO4 with straight-through ribbon cables (e.g., DIP-16 header to DIP-16 header --> adapter board --> DIP-14 header to DIP-14 header).

The boards are so cheap from China that I can easily get 20 made for the same price as 5, and I doubt I could even give away 19 of these boards for the SSM-IO4 configuration, so I was thinking I might as well add another socket or IDC header onto the board for other common parallel boards people may be using with their OP-80A. Or maybe a patch area and a 24 pin header (2 x 12) that would allow straight through ribbon cables to be used for most any socket from DIP-14 to DIP-24 or even DB-25.

Thoughts?

Mike
Click to expand...

Mike, do you want to borrow my original OP-80A or do you have one?
Cheers,
Corey
 
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Corey,

Thank you for your generous offer, but yes, I have an OP-80A. For now, I have it temporarily wired into the SSM-IO4 board using a DB-25 patch panel in the middle of two DB-25 ribbons cables I made (DIP-16 to DB-25 and DIP-14 to DB-25). I'm making the subject adapter board to make the cabling cleaner and more permanent.

In my Altair, I have the SSM-IO4 strapped at I/O address 6/7 with the negative going data available flag on bit 0 of the status register. This makes the OP-80A look just like an Altair 88-ACR cassette interface board to software. This means any load operation the Altair can do with its cassette interface I can do with the OP-80A without having to make any custom software. This includes loading BASIC and using the "CLOAD" command in BASIC to load programs.

Mike
 
Chuck(G) said:
Maybe Mike knows of a good reliable Chinese PCB fab house. I tend to stick with OSHPark. Good quality--and they seem to understand English. :)
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I've had good luck with ALLPCB and PCBCART so far. OSHPark doesn't like the output of my old-school PCB tools...

Mike
 
Chuck(G) said:
Maybe Mike knows of a good reliable Chinese PCB fab house. I tend to stick with OSHPark. Good quality--and they seem to understand English. :)
Click to expand...

By at home I meant "at his house". :)

It never occurred to me to have a production house make a one-off for me. But I do most things myself; maybe this is not normal, I have no idea.
 
KC9UDX said:
By at home I meant "at his house". :)

It never occurred to me to have a production house make a one-off for me. But I do most things myself; maybe this is not normal, I have no idea.
Click to expand...

I did etch a few PCBs when I was 12 and 13 years old, but that was the last time. For some reason, the quality wasn't great ;)

Mike
 
deramp5113 said:
I did etch a few PCBs when I was 12 and 13 years old, but that was the last time. For some reason, the quality wasn't great ;)
Click to expand...

I could say the same. But the ones I've made in recent years are much better. Layout in CAD makes a big difference.
 
While I still do wirewrap for some prototypes, I haven't etched a PCB in maybe 25 years. I have a Kepro PCB kit if someone wants to experiment. I can't testify as to the quality of the chemicals, but there are a few photosensitive PCBs in the thing.

But features have gotten small enough that just sending the artwork off to be fabbed is well worth the trouble. You get resist and silkscreen for no additional charge; the plated vias are good and the pads are all gold-flashed. Can't do that at home.

I've wondered about some of the low-priced 3D-printer-milling setups for doing PCB work, but I'd still have to worry about registration and vias.
 
Hi Mike,
Would you possibly consider bringing the signals out to a .1" pitch SIP header as that make interfacing to non-IDC or DIP terminated cables? I use a steady supply of SIP connectors to interface with test boards I build to play with. What ever you decide on, I would be interested in a few boards as I have an OP-80A and a more modern clone of one. I also have a number of IO-4 boards in my collection.
Regards,
Jeff
 
I've had decent luck with elecrow, but the qty makes a difference in the weight and the shipping. If I use DHL I usually get an order in just over a week. They've also got 5 or 10 green 10cm x 10cm for $4.90 or so.

Oshpark is fantastic for tiny boards where the price model is excellent. They are also useful to see what your gerber's look like.
 
PCB Cart is good stuff, I use them for anything that requires actual hard gold plating, like the XT-IDEs, Apple II protoboards, etc. N8VEM used them when that was a thing, and I believe John Monahan still uses them for all of the s100computers.com boards.
 
jgalinat said:
Hi Mike,
Would you possibly consider bringing the signals out to a .1" pitch SIP header as that make interfacing to non-IDC or DIP terminated cables? I use a steady supply of SIP connectors to interface with test boards I build to play with. What ever you decide on, I would be interested in a few boards as I have an OP-80A and a more modern clone of one. I also have a number of IO-4 boards in my collection.
Regards,
Jeff
Click to expand...

Sorry - too late ;) I decided to make the board clean and simple with just the 16 and 14 pin sockets to adapt between the OP-80A and the IO4. It’s so cheap that it’s not a big deal to make a different adapter for some other S100 board in the future as needed. The boards will be here soon and I can certainly send you any adapters you could use.

Mike
 
deramp5113 said:
Sorry - too late ;) I decided to make the board clean and simple with just the 16 and 14 pin sockets to adapt between the OP-80A and the IO4. It’s so cheap that it’s not a big deal to make a different adapter for some other S100 board in the future as needed. The boards will be here soon and I can certainly send you any adapters you could use.

Mike
Click to expand...

Hi Mike,
No worries! Thank you for offering these. I will take 2 boards if you can spare them. BTW, thanks for all the work you for our hobby. I use your ALTMON in my 8800c with Martin's 88-2SIOP and also in my test rig with a IO-4 configured as an 88-2SIO and they both work great.
Regards,
Jeff
 
Well that was quick - the boards are here already. $5 total for 30 boards (though shipping was $17). I don't know how they can make a business of this.

Mike
 
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