Merging TWO BASIC Program Files — part-1 + part-2

This little guide shows how to merge two BASIC program files named part-1 and part-2 into a single, running program.
The method is based on the merging procedure described in Peeks and Pokes on the Commodore 64 (Liesert, 1st edition, 1985), page 41. A pdf document of this can be found on the web-archive.

This we now use to merge the generated sprite printing lines with the program in which we want to use them.

🧩 Step-by-Step Merge Guide

1️⃣ Load the first part

Load part-1 into memory (e.g. LOAD "part-1",8).
Make sure it sits safely in memory.

2️⃣ Note the end-of-program pointer

Find the memory address at the end of part-1 (this is where the next line will be appended).
This address is stored in pointers at the top of BASIC memory.
for this we read the memory location using the peek command:


  print peek(43), peek(44)    make a note of those two values
  poke 43, (peek(45)+256*peek(46)-2) and 255
  poke 44, (peek(45)+256*peek(46)-2)/256
  new

3️⃣ Load the second part

Use `LOAD "part-2",8
This loads part-2 directly after part-1 in memory.

4️⃣ Fix the pointers

Update the first two bytes (low, high) of part-2’s first line to point to the correct memory address where part-2 now resides.
this we do with the two value we fount with the peek (43) and peek(44)


  poke 43, value-1
  poke 44, value-2

5️⃣ Save the combined program

Once merged and pointer-adjusted, save the entire combined program (e.g. SAVE "merged",8)
You now have a single file that runs both parts in sequence.

🔍 Notes & Tips

Always backup the originals before merging.

Combining the parts

Using the merged program

As an exmample here the combined programs and a small example on how to use the sprite definion part and the part to show the sprite.

Example showing speed

Here the final result showing how fast it can be reprogramming a sprite by using the print command.

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