Display on a Type 340 display - Eureka!

[Francis King]

Hello. 

I have found a way to draw a dot on a Type 340 display. Based on the Lorenz code.

title Draw a point

A=1
DIS=130
N=1

define display data
    conso DIS, 200
     jrst .-1
    datao DIS, data
termin

start:    seto A,
          .iotlsr A,
          cono DIS,100
init:     MOVSI A, -N  
          display <[020016]>
loop:     display TABLE(A)
          AOBJN A, loop
          JRST init 
table:    XWD 220055, 022055
end start

I've also discovered that macros in Midas are recursive, so that the following code works:

Title test of macro recursion

define nop
     JUMP
termin

define NOP2
      NOP
      NOP
termin

start:    nop2
           .value
end start

[Francis King]

I have written an assembler for the Type 340 display. It runs within MS Excel, and turns a sequence of commands into octal, suitable for use with Midas. I have put it here:

https://github.com/FrancisKing3/PiDP-10

I'm not sure it handles the increment mode properly - a work in progress.

There are still a few loose ends - can anyone help me please? The documentation for Character Mode is missing details. it says that the character mode keeps going until the Type 342 Character Generator decodes an esacpe chracter, but doesn't say what this is. https://bitsavers.org/pdf/dec/graphics/H-340_Type_340_Precision_Incremental_CRT_System_Nov64.pdf. Can anyone think of a program which is written in Midas and whuch text to the screen?