Small Programmes

Blanks are significant if among the last 8 characters before a tick, see proposal for formatting and comments

Test halt on overflow

As it is rather unusual that the machine stops on overflow, here is a small test program:

halt on overflow
;zzz0700'
/zzz0700'
00   b0016'   get start
01   a0017'   stops if overflow
     u0001'   loop
variables:
;zzz0716'
,zzz0002'
16 7ww00000'  start
17 00002000'  increment
go
.zzz0700'

Hello

The follwing program to print Hello on the console is rather untypical:

Print Hello
;   0600'
/   0600'
  xp1600'	CR
  xz0000'	sync
  xp0800'	UC
  xz0000'
  xp4900'	H
  xz0000'
  xp0400'	LC
  xz0000'
  xp3700'	e
  xz0000'
  xp0600'	l = 1
  xz0000'
  xp0600'	l
  xz0000'
  xp3500'	o
  xz0000'
  xz0800'	pause unless Br8
   u0000'	repeat
.   0600'

Simple Loop

Example looping program that prints a given number of asterisks:

simple loop
;   0900'
/   0900'
00  xp0800'	upper case
    xz0000'	sync
    xp1600'	CR
    xz0000'
     b0022'	start value
     u0007'	avoid data wait
06   b0020'	get counter 
07   s0021'	minus step 
     t0013'    done if negative
     h0020'	save
    xp1000'	print *
    xz0000'
     u0006'	repeat
13  xz0000'	halt
14   u0000'	restart

data:
;   0920'
,000  03'
20 00000000' counter
21 00000010' decrement
22 00000050' initial
start:
.   0900'

Printing all digits

The following example prints all characters in numerical sequence, all digits as an example. It shows how to modify instructions:

   print 10 digits
   ;zzz0800'
   /zzz0800'
   00  xp0400'	lower case
       xz0000'
       xp1600'	CR
       xz0000'
   04  xp0200'	print 0
       xz0000' 
        b0004'	last printed
        e0022'	mask char code
        a0020'	increment
        y0004'	save 
        s0021'	end?
        t0004'	no
   12  xz0400'	stop for repeat  
        b0023'
        y0004'	start over
        u0000'
   data area:
   ;zzz0820'
   ,zzz0004'
   20 00000400' increment
   21 00002700' last digit 9 = x26, plus 1
   22 0000ww00' mask
   23 00000200' digit 0 
   start here:
   .zzz0800'

Fill and clear a track

Fills a track with its sector numbers, and then clears the same track again. To fill in physical order, use 0q4 in location 34; for logical order, use 004 If Break 4 is not set, the programme waits before clear; if Break 8 is not set, it waits after clear before repeat.

   fill and clear a track 
   ;zzz0400'
   /zzz0400'
   00   c0033'    clear acc
        c0033'    clear sector
   02   b0033'    get sector
        a0032'    add track
        y0005'    set destination
   05   hzzzz'    store
        a0034'    advance
        e0035'    mask sector
        h0033'    save
        s0036'    ? >0
        t0012'    no, done
        u0002'    yes, repeat
   12   z0400'    pause unless BR4
        c0033'    clear track
        c0033'
   15   b0033'
        a0032'
        y0019'
        c0037'    discard and clear
   19   hzzzz'    clear mem
        b0033'
        a0034'
        e0035'
        h0033'
        s0036'    ? >0
        t0027'    no, done, again
        u0015'    yes, repeat
   27   z0800'    pause unless BR8
        u0000'
   data area:
   ;zzz0432'
   ,zzz0006'
   32 00002100' track to fill
   33 00000000' current sector
   34 000000q4' sector increment
   35 000000wj' sector mask
   36 00000002' to test for zero
   37 00000000' trash to clear acc
   start here:
   .zzz0400'