FAQ: ZX extensions

ZXNet echo conference «real.speccy»

From Denis Dmitriev To All 4 July 1998

Hello, Valerij!

Once on June 14, 98, Valerij Kozhevnikov sent a
letter to All:

VK> ============== CMOS ====================
VK> (* general description)
VK>
VK> Glukъ #??F7 LD A,regnum ; (0...#3F)
VK> **
VK> OUT (#F7),A
VK> IN A,(#F7)
Here #BFF7 is the address register, #DFF7 is the data register,
bit7 in #EFF7 - (1/0) on/off CMOS ports.

In general, about the subject - I’m telling you I presented it in a slightly different form: there is a large table that lists all existing ports; the entire
address space of ports is sorted in order
ascending order of the _low_ byte of the port address (this is easier
to sort, because if a device has several different ports,
then the low bytes of the address are the same, or differ
only in individual bits), but the ports are from one and the same
devices are grouped together,
for each port the address bits are indicated, by which the port is selected; this port fully describes
the layout of the involved bits; it is better to
leave the unused bits -reserved- at the discretion of the authors.

For example, how the description of CMOS ports by Gluk would look:

That's the spirit of the sign.
From it you will immediately see which ports are occupied, which bits
you can decrypt your own device, etc.
Therefore, “standard”
ports (#xxFE, #7FFD, etc) should also be listed in this table.

Well, and then you can describe the ports _functionally_, as
it’s done for you, with a brief description of the device and its
ports.

And in the appendix to the subject it will be possible to include _full_
descriptions on working with allthe given devices and
their diagrams (to the extent possible, if there are docks), but it’s already time...

===========================================================
... I’m really daydreaming ;)
Well, what’s your idea about the structure of the subject?

S best, Denis.

From Andrey Isaev To All 9 July 1998

Hello, Denis!
4 Jul 98 Denis Dmitriev was chomping at the bit in the hope that Valerij Kozhevnikov
would read about the FAQ: ZX extensions, I read it and decided to answer:

DD> Well, what's the idea about the structure of the subject?
Very good, but who will compile it? or will the whole world work together? It wouldn’t be bad if every knowledgeable person made up part of the subject, and
then everything is sent to someone alone and glued together into one big fact.

Sincerely, Andrey.

... The hedgehog is a proud bird: if you kick it, it won’t fly!