The DCJ11 was the last PDP‑11 processor developed by DEC. When you first look at it and try to read the datasheet you might be overhelmed by the complexity and features of this CPU. But compared to other 16-bit processors of this era it was in fact very powerful but yet still easy to use. For those interested I have put together what I know about the DCJ11.
Read moreEurocard sized Single Board Computer using a DCJ11 which implements the basic features of a breadboard PDP-11/Hack with an expansion slot that allows for further enhancement up to a fully functional PDP-11 running RT-11.
Read moreDetailed building instructions for the SBC giving a step by step description of each individual step.
Read moreThe DCJ11 SBC is prepared for more RAM and also provides the necessary logic to decode non-existing memory address
Read moreInstead of using the six TTL logic devices you can use a GAL16V8. This will save you sockets, soldering time and the need to purchase many different TTL logic components.
Read moreFor those without the possibility to get their hands on a DC319 UART I have created a small CDP6402 adapter to plug into the socket for the DC319.
Read moreIn this article I go more into the details of the circuit used for the DCJ11 SBC
Read moreNow as the DCJ11 SBC is completed what can you do with it? Here are some first tests you can run using the console and ODT.
Read moreFor more fun, projects or any advanced feature you would develop your own PCB that goes into the card edge slot, the expansion slot. However for many small projects this would be overkill. Therefore I built an interface to savely connect the DCJ11 SBC to a breadboard and also show some experiments you can do with this interface
Read moreA nice feature to the DCJ11 SBC would be programmable IO. The ubiquos VIA W65C22, the CMOS version from Western Design Centre of the famous MCS6522 from MOS Technology Inc. seems to be on the top of the wish list
Read moreOnly a console and ODT is a little dull, so why not add a second serial interface and some EERPOM to make the DCJ11 SBC a bit more useful. And as we are at it why not add some GPIO. This second serial interface still will not make the DCJ11 SBC into a fully functional PDP-11 capable of running major software, but it will enable some interesting applications
Read moreForth exists as well as a stand-alone program für the PDP-11 and to my surprise, it does not make use of interrupts, therefore it can be loaded to the DCJ11 SBC without an expansion board or additional hardware. However that’s not all, the story goes further.
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