My PDP-11 related electronic projects on My PDP-11 Projects

Instead of counting cycles a far better approach is to use a timer.

The KDJ11-E had a built-in RTC using the DS1215 phantom clock chip.

Already during the debugging of the RLV12 Emulator V1.0 I had big troubles to physically access the programming interfaces, like JTAG and ISP, as well to change the SD-Card.

For reasons already mentioned in the previous post I decided to build a new version of the RLV12 Emulator.

In the meantime the MCU firmware has changed a lot and therefore I wanted to give some update about revisions, bug fixes, open issues and enhancements

The FAT library in fact consists of a collection of functions.

Introduction

The RTC clock is directly supported by various operating systems of digital.

I’m apparently not the only one that was interested in the RTC of PDP-11.

When I realized that the RTC in the newest PDP‑11 was just a DS1215 from Dallas and it was just a one-bit interface in the Additional Status Register it was obvious that I wanted this feature in my PDP‑11/Hack.

Nothing beats small programmable logic devices, also called SPLD, when you build a small computer or a small logic circuit when the logic uses various combinations of signals and it’s inverted values to create the necessary function.

At the beginning of the FAT library I had this idea of IO control block.

The RLV12 Emulator has a built-in logging function that stores all controller activities in a circular buffer in the RAM of the microcontroller

The RLV12 Emulator has a built-in logging function that stores all controller activities in a circular buffer in the RAM of the microcontroller

This is a small side project not only related to PDP-11, the basic idea was to first read and write to floppy drives with just a microcontorller and without a FDC (floppy disk controller) chip

I have a collection of macros and subroutines that I very often use in my AVR assembler projects

Once you have mastered reading a floppy the next step is writing a sector

In this section I show how to format a SD-Card and prepare it to be used in the RLV12 Emulator

In this section I show how to format a SD-Card and prepare it to be used in the RLV12 Emulator

This is a study how to read and write Floppies without a floppy disk controller.

Here is the source code of a collection of my projects.

During the development of my PDP‑11/Hack system I came up with the idea of a generalized interface between the Q-Bus and a microcontroller in order to be able to use the variety of the IO features and the flexibility of the software in a microcontroller.

A detailed description of the concept of the Q-Bridge.

Some information about this home page

The RLV12 was a disk controller for PDP-11 systems that supported up to four RL01/02 disk drives.

The PDP-11/Hack is a self built PDP-11 using the DCJ11, a single chip implementation of a PDP-11.

Why does someone want to build it’s own PDP-11.

The schematic of the Q-Bus version of the RLV12 Emulator with some additional information

The RLV12 Emulator emulates a RLV12 Q-Bus disk controller in a PDP-11 Systems with up to four units attached.

An overall description of the logic

The following blog describes the overall architecture and the design principles I used to build the system

Here you find the BOM and the building instructions in case you want to build your own RLV12 Emulator.

The PDP-11/Hack uses a passive backplane as system bus.

The heart of the system is the CPU board.

A multifunction board combines several options on a single board and was very common for small PDP-11 systems.

For a fully functional PDP-11 system we need a disk drive.

A PDP-11 is more fun to use, when you have more memory, especially when your system supports 22-bit addressing.

This is a short resume about my Plessey Peripherals PDP‑11.