On 4/12/22 6:37 AM, Bill Gunshannon via cctalk wrote:
So, this just gets more and more confusing. (Have I really been away
from all this for that long!!!)
I dug up the tech manuals for the two of them (buried deep in my
stacks of books) and compared them. And you are, of course, right.
Which just brings more questions.
Why do Model I cassette programs (not BASIC) not run on the Model III?
Why did they relocate a Model I program that had a specific Model III
version to a slightly higher location in memory?
It was common to add a loader for cassette programs that would
load the program in higher memory and relocate to the original
location so they could be loaded from disk (on both the Model I
and Model III). This is because the original location would
typically be in low RAM used by the OS.
In some cases there wasn't a disk version of the program, in
other cases it was to avoid having to buy the disk version.
For games if there was a disk version the only likely change
was to add a high score table that was written to disk, so
not worth paying again. There were a few games that added
extra features to the disk version but right now I can't
remember which ones. I think Big Five did a few this way.
--
Eric Dittman
