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PB-10 programmer schematics

Dwight Elvey

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Hi
I see the post about someone trying to find information for the programmer they have. It is a shame that there isn't more information for these devices.
I've had to repair my Needham PB-10 once. I realize that manufactures like to keep their schematics private but the Needham PB-10 is now, way, obsolete and no longer manufactured. No one is interested in building one today, especially with the number of cheap programmers available from China right now. I just want to be able to fix the one I have when I need to use it. I had to do a lot of signal tracing and note taking to figure the various parts out. There were even some tricky things done to the circuit to make is difficult to easily copy the hardware. Part of the lower address bits were done with a counter chip and they'd swapped a couple of the address lines, just to make it annoying. I hardly think that would stop a serious attack. It just makes it a little more trouble.
I've made a number of routines to set the various pins to values so I can look to see if anything is running slow with a scope. I did this in Forth but one could easily convert it to some other language. It is not a schematic, just what the signals do. If anyone is interested I can post this information.
Dwight
 

gekaufman

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Jul 31, 2014
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New Hampshire, USA
I’m pretty sure that Needham did release the schematic for the PB10. They were a great company to deal with, but sadly no longer in business (the current owners have the name but don’t really support any of the original products).

I can see if I still have a schematic at home. At the very least my PB10’s were socketed so repair should be pretty straight-forward. If all else fails I believe I have spare boards and rarely use the BP10.

- Gary
 

Dwight Elvey

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I would love to have a schematic. I don't need to repair it now. It seems to work fine. It had one of the open collector buffers fail. I've long since replaces that part.
Dwight
 

gekaufman

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I found a print-out of the schematic. The original file might be on one of the 5.25" disks but I'll have to pull out an older system to look.

I scanned the printout to http://www.the-planet.org/PB-10_Schematic.pdf

Not perfect, but should be good enough for repair.

The only failures I've ever had were in the 7407's or the cable. I also have the micro adapter board here somewhere...

Enjoy!

- Gary

I would love to have a schematic. I don't need to repair it now. It seems to work fine. It had one of the open collector buffers fail. I've long since replaces that part.
Dwight
 

Dwight Elvey

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I found a print-out of the schematic. The original file might be on one of the 5.25" disks but I'll have to pull out an older system to look.

I scanned the printout to http://www.the-planet.org/PB-10_Schematic.pdf

Not perfect, but should be good enough for repair.

The only failures I've ever had were in the 7407's or the cable. I also have the micro adapter board here somewhere...

Enjoy!

- Gary

Yep, same 7407, open collector buffer. The PDF looks fine. Thanks.
One other question, you wouldn't happen to have a 8748 adapter would you? If I had a schematic I could make one.
Dwight
 

gekaufman

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Dwight -

I do have an 8748 adapter, but no schematic. I think I have a spare, but couldn't easily locate it last night. I'll keep looking, if I do have a spare I certainly don't need two.

I found the original PB-10 schematic file on floppy, but it's a .PRN file I'm guessing it's formatted for some "standard" dot matrix format, perhaps Epson. If it's of interest I could pass it along.

Yep, same 7407, open collector buffer. The PDF looks fine. Thanks.
One other question, you wouldn't happen to have a 8748 adapter would you? If I had a schematic I could make one.
Dwight
 

Dwight Elvey

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The adapters were not overly complicated for these as I recall. If you don't find the extra, it shouldn't be too much to trace out the leads.
I have the adapter for the 8751s but have always wanted one for the 48 series parts.
Dwight
 
Last edited:

gekaufman

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I located my spare PB10 87xx adapter board, a picture is attached.

This board supported 8751's, 7742's, 8748's, 8755's etc. I believe it was a later design than the single 8751 adapter you have.

You're welcome to borrow it for copying - or I'd be happy to trade it.

= Gary

The adapters were not overly complicated for these as I recall. If you don't find the extra, it shouldn't be too much to trace out the leads.
I have the adapter for the 8751s but have always wanted one for the 48 series parts.
Dwight
87xx Adapter.jpg
 

Dwight Elvey

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I located my spare PB10 87xx adapter board, a picture is attached.

This board supported 8751's, 7742's, 8748's, 8755's etc. I believe it was a later design than the single 8751 adapter you have.

You're welcome to borrow it for copying - or I'd be happy to trade it.

= Gary

View attachment 54074

I'd love to track it out and make a schematic. It needs a different zif and cable to go to the 87xx part. From the schematic I should be able to determine what that would look like. I do have the 8751 adapter. The 8755 is programmed differently than the 8755A. I'd need to look into that if I ever wanted to do a 8755A. We can move to email. You have the right one.
Dwight
 

bnice7

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Apr 1, 2019
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Hi there, apologies for bumping this older thread but I figure you guys might be able to help me out. I have a PB-10 and I'm trying to find (or build) an adapter that will work for programming 16-bit EPROMs on the Needham, such as a 27C400. I'm not finding much information on the internet regarding the old adapters and I'm really not sure where to start. My understanding is the adapters for these were pretty simple, but I'm not sure if it's just re-mapping the address lines, or if some additional logic is required to toggle the higher address bits for the 16-bit chips.
 

Dwight Elvey

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It uses 16 address lines to program and can only be programmed in the 16 wide mode. The PB-10 doesn't do a 16 wide data without some type of adapter. It is possible to write code to do it with some form of adapter. It would need both data and address latches to extend the function of the programmer.
I'm assuming you have a quartz windowed EPROM and not a one time programmed part. If it is a one time windowless one and it has been previously programmed you can only turn 1's to 0's and not 0's to 1's.
It is a doable project with a windowed chip as the programmer can be set to 12.5v, used for programming. It might be easier to setup an Arduino to do it though.
Dwight
 

bnice7

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Apr 1, 2019
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Thanks Dwight, the software for the programmer does include the 27C400 (windowed EPROM), but it is asterisked in the device list which implies the adapter is required. So I believe the code is there and it's just the physical adapter that I'd need. I ended up buying an "ADP-054" adapter which is intended for a Willem programmer, but I believe it'll have the logic on it. Should be enough to get me started anyway. Otherwise I can always go the Arduino route, but I'd really like to try to make use of this Needham's. I actually really like the front-end software.
 

Boxnut

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Mar 24, 2021
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Hi. sadly, the PB10 does not support the 27C400 and can't find it supported with the EMP-20 either
The only adapters for the PB-10 were for microprocessors like 8751. 8748 etc. everything else you use the standard ZIF adapter.
Sorry this is so late, I don't often work with these older devices.
What you might try is looking at Willems GQ-4X4. Supports far more devices and lots of adapters available for newer chips.
 
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