[0/5] ZXZIP_v1.02s for Pentagon-512K

Greetings, oh venerable All!

*** Posted with the permission of the Moderator.

ZXZIP512
========

Epigraph: “May the author of ZXZIP forgive me...” ;-)

Adaptation of the program “ZXZIP_v1.02s” for extended memory of
computers "Pentagon-512K" (6&7 bits of port #7FFD).

Last edition on 08/15/97.

As you know, ZXZIP_v1.02s is "tailored" for the expanded memory of the computer "ZS-Scorpion_256". Those. If this (additional)
memory is found, it will be used as
an additional buffer for long input files (for 255 sectors, for example). In this case, the _entire_ file is loaded into the "brains", and additional access to the disk with the source file ends there: all subsequent uploads will take place
from the electronic disk, which, to some extent, can speed up the process of packing the file.

This version of such a useful software product was adapted by me for the happy owners (of which I am) of expanded memory according to the Pentagon “standard”. Now ZXZIP will work on as many as three Speck configurations:

1. ZX_Spectrum-128K
2. ZS_Scorpoion-256K
3. Pentagon-512K (NEW!) (or any other with similar upper
memory expansion)

ZXZIP512 uses _only_ eight (8)additional
pages of the Pentagon's upper memory, which are selected by the _sixth_
(6) bit of port #7FFD (the seventh bit of #7FFD is _always_ reset! [bit_7=0]). When accessing port #7FFD, the
_full_ sixteen-bit address is used!
During program startup, a test is performed for the presence of additional
eight pages addressed by the sixth bit of port #7FFD.
If these same eight pages are not found, then The original "ZXZIP_v1.02s" will not change _a single_byte_!
If everything went well, then a corresponding line will appear on the screen, notifying you that you are the happy owner of an advanced Speck:

"Pentagon 512 expanded memory detected"

Yes, +more: all abbreviations like "1.02s" after such a "detect" will be replaced with "1.02p". ;) This is to make it clearer what kind of “brains” we are currently working with.

Now, having guessed your question “and how bad is all of this?” - I immediately answer it: I have been using this program since the appearance of the adapted version. I work only with 512K. I pack a lot often. Until now I haven't discovered _a single_glitch_! ;)

Best regards, Felix.

[ZX]