#eff7
ZXNet echo conference «real.speccy»
does anyone know all the bits of the subject's port. known:
0 - hardware multicolor
1 - 512x192
2 - memory blocking over 128kb
3 - 16 ink / 16 paper / 16 border
4 - gigascreen
7 - kmos
...bye.All! ...tigrr//bw::ceg
... some music CD
There is no clear standard. There is a known case where all bits except the 1st
were used to change color in 512x192 mode.
Hello, Igor!
09 Nov 02 21:32, Igor Turashev -> All:
IT> does anyone know all the bits of the subject port. known:
IT> 0 - hardware multicolor
IT> 1 - 512x192
IT> 2 - memory blocking over 128kb
IT> 3 - 16 ink / 16 paper / 16 border
3 never seen...
IT> 4 - gigascreen
IT> 7 - kmos
3 - it seems there was a switch here 32kb cache
5 - opening dos-ports (probably a ROM will also appear)
6 - rom disk - connecting additional ROM...
Perhaps on 3 some have turbo mode control
Sincerely, Evgeniy.
5,6: Sound Blaster and 384x304, respectively
another option: 5,6 - the high address of the ROM disk and its latch
there was also an option where the low bits of the subject switched the cache to different ROM windows, but
IMHO it didn’t catch on.
the docks were in Mr. Gluck’s “Ode to the Clock” in Deja Vu#8 (but he wrote about #fffc) and
"Pentagon 1024" in Born Dead#10.
by the way, the port was invented by VMG :)
- Alone Coder [ZX-Guide] [ACEdit] [PT] [Chip] [STS] [AlCoNews] [ANSI] [8col]
EP> 3 I have never seen...
circuit in echo or soap?
EP> 6 - rom-disk - connecting additional ROM...
6 more 384x304 by AlCo, supported by his own ansi-viewer. poor subject
port... :)
...bye.Eugene! ...tigrr//bw::ceg
... Jazzkantine - Ich Wuerd Die Welt Gern Veraendern ...
Sunday November 10 2002 23:53, Dima Bystrov for some reason wrote to Igor Turashev:
DB> Hello Igor!
DB> 09 Nov 02 21:32, Igor Turashev wrote to All:
IT>> ...hi.All!
IT>> Does anyone know all the bits of the subject port. known:
IT>> 0 - hardware multicolor
IT>> 1 - 512x192
IT>> 2 - memory blocking over 128kb
Port #EFF7.
bit 0 - screen mode 256*192, byte of color per byte of dots.
In #6000-#77FF there are attributes, they are standard, with the exception of
bits 6 and 7. Here they are paper bright and ink bright, respectively.
--------------------------------------------------------------
bit 1 - mode screen 512*192, b/w.
Well, this is clear to everyone.
--------------------------------------------------------------
bit 2 - blocking RAM over 128K.
This bit also controls the assignment of bit 5 in #7ffd.
1 - RAM over 128k is blocked, bit 5 in #7ffd works
with the standard latch "48k only".
0 - the upper memory is available, and bit 5 in #7ffd is used to
manage memory over 512k, otherwise called the “Pentagon-style meter.”
--------------------------------------------------------------
bit 3 - enable TURBO.
(planned, IMHO no one has implemented it)
Some used this bit as “write permission” in the stat. RAM,
connected by bit 6.
--------------------------------------------------------------
bit 4 - GIGASCREEN.
Hardware interlace.
As you know, Spec has two screens, and each of them has 192
lines. The interlacing cycle takes two frames. In the first screen, even lines from the zero screen and odd lines from the first screen are displayed, in the second - odd lines from the zero screen andeven ones from the first.
The effect is similar to when each interrupt switches the screen, but
without obvious flickering.
By the way, this bit can be used together with 0 or 1, interlacing
how many colors or dots on the screen.
--------------------------------------------------------------
bit 5 - enable DOS ROM and VG ports for direct access from RAM.
_Has this been done by many?_
--------------------------------------------------------------
bit 6 - locking the ROM and connecting another, or 16k stat. RAM.
In 1998 it was like this, in these 16k statics people loaded the required
version of DOS and used it.
Then someone suggested switching halves of
Cache-32 with this bit, although switching of these halves seemed to have already been
set to #7ffd bit 4.
Later this bit was used for 384x304 graphics without curb. Apparently
Cache RAM, turned on instead of ROM via IN #FB, turned out to be more convenient.
--------------------------------------------------------------
bit 7 - enabling access to the clock.
IMHO, why don't you need to hide the clock.
WBR, Jason.
/*e-mail: jason2000(scary dog)yandex.ru ICQ: 62235830*/
/np:/*silence*
IT> 6 another 384x304 by AlCo, supported by its own ansi-viewer.
IT> poor subject port... :)
Any memory expansions on this port are insanity, IMHO this should be a port
purely of screen expansions. Otherwise, glitches with the screen when clicking pages
are guaranteed unless you are clever.
Bye, Igor!
Arc/exRLDG
...cut...
bit 5.6 - reserved for Rom-Disk. Since this thing is not
widespread, it is suggested: bit 5 - enable Sound
Blaster (see ZX-Guide #2), bit 6 - enable 384x304
(ibid.).
...cut...
This info is from the description on the Pentagon 1024k.
That seems to be all. Packeda!
deadie.horrorsoft.cpu [6912] [hrwI] [ampack] i speccy
12.11.2002, Alexander Araktcheew wrote to Igor Turashev:
AA> Any memory expansions on this port are insanity, IMHO this should be a port
AA> purely for screen expansions. Otherwise, glitches with the screen when clicking pages
AA> are guaranteed unless you are clever.
In Spec, everything is so mixed up that it is useless to organize it.
Bye. Roman.
AA>> there should be a port of pure screen extensions. Otherwise, glitches with
AA>> the screen when clicking pages are guaranteed unless you
AA>> are smart about it.
RM> In general, everything in Spec is so mixed up that it is useless
RM> to organize it.
Uh-huh...
In particular, this has greatly brought its end closer...
Bye, Roman!
Arc/exRLDG