Learning PDP-11

Reverse engineering PDP-11 BASIC: Part 26

This short post describes TRAP 116 and the BASIC RUN, STOP, END and RANDOMIZE commands. For context and a list of other posts on this...

daveor

Apr 7, 2021

Reverse engineering PDP-11 BASIC: Part 25

This post describes the BASIC FOR and NEXT loop commands. For context and a list of other posts on this topic, see the PDP-11 BASIC...

daveor

Apr 6, 2021

Reverse engineering PDP-11 BASIC: Part 24

This post describes the BASIC READ, INPUT and RESTORE commands. For context and a list of other posts on this topic, see the PDP-11 BASIC...

daveor

Mar 27, 2021

Reverse engineering PDP-11 BASIC: Part 23

This post describes the BASIC IF command. For context and a list of other posts on this topic, see the PDP-11 BASIC reverse engineering...

daveor

Mar 22, 2021

Reverse engineering PDP-11 BASIC: Part 22

This post will describe the operation of TRAP 124 and the BASIC DIM and LET commands. For completeness, I'll also describe the DATA and...

daveor

Mar 21, 2021

Reverse engineering PDP-11 BASIC: Part 21

In this post we'll look at the expression evaluation code. Expressions are used all over the place and the main entry point to parsing...

daveor

Mar 18, 2021

Reverse engineering PDP-11 BASIC: Part 20

This post will describe the operation of a few TRAPs that are used to support the functionality that will be analysed in the next posts....

daveor

Mar 18, 2021

Reverse engineering PDP-11 BASIC: Part 19

In this post I'll describe user-defined functions and the BASIC DEF command, starting with some TRAPs that support its operation (TRAP...

daveor

Mar 3, 2021

Reverse engineering PDP-11 BASIC: Part 18

This post will describe the operation of the ASCII-to-floating point conversion code, TRAP 6. You will need to have read Part 14, Part...

daveor

Mar 2, 2021

Reverse engineering PDP-11 BASIC: Part 17

This post will take a look at some more floating point manipulation TRAPs; TRAP 26 (floating point division) and TRAP 34 (floating point...

daveor

Mar 1, 2021

Reverse engineering PDP-11 BASIC: Part 16

This post is about multiplication. There are three different multiplication TRAPs found in the PDP-11 BASIC code, with a different one...

daveor

Feb 27, 2021

Reverse engineering PDP-11 BASIC: Part 15

This post will examine some of the floating point operations. We'll be looking at TRAP 24 (negate a floating point number), TRAP 20 (add...

daveor

Feb 24, 2021

Reverse engineering PDP-11 BASIC: Part 14

In this post I'm going to start the analysis of the floating point number code. I will be looking at the PDP-11 BASIC representation of...

daveor

Feb 22, 2021

Reverse engineering PDP-11 BASIC: Part 13

Update 1st March 2021: This post has been updated to reflect refined understanding of TRAP 64 arising from analysis of the floating point...

daveor

Feb 15, 2021

Reverse engineering PDP-11 BASIC: Part 12

In this post I'll describe some of the BASIC commands that use runtime state storage, including GOSUB, GOTO and RETURN. For context and a...

daveor

Feb 10, 2021

Reverse engineering PDP-11 BASIC: Part 11

This posts begins the analysis of the BASIC program's runtime state management. I'll start with a quick introduction to how the runtime...

daveor

Feb 9, 2021

Reverse engineering PDP-11 BASIC: Part 10

In this post I'll be looking at how the SAVE, OLD and DELETE BASIC commands work. For context and a list of other posts on this topic,...

daveor

Feb 8, 2021

Reverse engineering PDP-11 BASIC: Part 9

In this post I'll be looking at how the BASIC LIST command works. For context and a list of other posts on this topic, see the PDP-11...

daveor

Feb 5, 2021

Reverse engineering PDP-11 BASIC: Part 8

In Part 6 I analysed the code that: Determined whether the user has pressed return, in which case control returns to the beginning of the...

daveor

Feb 3, 2021

Reverse engineering PDP-11 BASIC: Part 7

The purpose of this post is to lay the groundwork required to complete the analysis of the main syntax parsing loop. There are a few...

daveor

Feb 2, 2021

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Learning PDP-11

Reverse engineering PDP-11 BASIC: Part 26

Reverse engineering PDP-11 BASIC: Part 25

Reverse engineering PDP-11 BASIC: Part 24

Reverse engineering PDP-11 BASIC: Part 23

Reverse engineering PDP-11 BASIC: Part 22

Reverse engineering PDP-11 BASIC: Part 21

Reverse engineering PDP-11 BASIC: Part 20

Reverse engineering PDP-11 BASIC: Part 19

Reverse engineering PDP-11 BASIC: Part 18

Reverse engineering PDP-11 BASIC: Part 17

Reverse engineering PDP-11 BASIC: Part 16

Reverse engineering PDP-11 BASIC: Part 15

Reverse engineering PDP-11 BASIC: Part 14

Reverse engineering PDP-11 BASIC: Part 13

Reverse engineering PDP-11 BASIC: Part 12

Reverse engineering PDP-11 BASIC: Part 11

Reverse engineering PDP-11 BASIC: Part 10

Reverse engineering PDP-11 BASIC: Part 9

Reverse engineering PDP-11 BASIC: Part 8

Reverse engineering PDP-11 BASIC: Part 7

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