Scheme

Did you ask for a diagram? Here: trimay :)
With another Pentagon turbine.

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(c)1998 AXLR
──────────────────────────────── ───────────────────────────

So, what needs to be done to make a regular controller
work with high-density disks? If the computer already
has a turbo mode installed, then all the modifications take literally
an hour, and if not, well, here we offer an already modified
turbo diagram for the Pentagon-assemble.
So, even if you already have a turbine, you will have
to modify it a little. Actually, there are two improvements here: one for
turning on the turbo when DOS is running, the other generates /wait
when the processor accesses the ports.
Special mention should be made about the latter. It has been noticed that some
KR1818VG93 copies, namely 1993 and later
years of production, do not work well in the turbo. and the quality of exchange with
the disk does not seem to be affected (they haven’t tested it specifically),
but who, VGshku, knows.

It would be best to provide a complete turbo diagram for the Penta
gon, but with modifications:

*100pF
LA3 ─┬─ TM2 free elements TM2 and
┌──┐ === ┌──┬──┐ LA3 can be found on board
D3:2─────│ &°───┴─────13° R│ │ компа
D3:3 ─────│ │ ┌────12│ D│ _│
└──┘ │ ┌──11/ C│ Q°8─────> D5:2
D10:12 ───────────┘ │ ┌10° S│ │
D15:5 ──────────────┘ │ └──┴──┘
+5V

DD1 +5В
┌──┬──┐ │
D45:3 ────────┬──────────────────────2│A0│ │ █К47
│ +5В ───5│A1│ │ │
│ ├──┤Y0│4──┴───>Z80:6
D2:9 ────────────────────────────┬───3│B0│ │ К10
│ ┌─────6│B1│Y1│7─███──>Z80:24
│ │ │ ├──┤ │
│ +5В DD3.1 ┌──────1│ S│ │
│ │ ┌──┬──┐ ││ │ ┌15°OE│ │
│ ├─1° R│ │ ││ │─┴─ └──┴──┘
│ ┌──2│ D│ _│ ││ │
└──────3/ C│ Q°6┘│ │
│└─4° S│ │ │ │
│ └──┴──┘ │ └───────────────┐
│ └───────────────┐ │
DD4.2 └──────────────────────────┐ │ │
┌──┐ │ │ │
/bit7#FF───4│ 1│6────┐ │ │ │
D76:9 ─────5│ │ │ │ │ │
└──┘ │ │ │ │
+5В DD5.1 │ DD4.3"NORMAL" │ │ │
│ ┌──┬──┐ │ ┌──┐ S1 │ │ │
HLD──┬──1° R│ _│ └─13│ 1│11───── \ │ │ │
│├─2│ D│ Q°6────┬─12│ │ ┌─ \──────┘ │ │
/IP─────3/ C│ │ │ └──┘ │ │ │
│└─4° S│ │ │ DD6.1 │"TURBO" │ │
│ └──┴──┘ │ ┌──┐ │ │ │
│ └──1│ &│3────┘ │ │
└──────────────────2│ │ │ │
└──┘ │ │
│ │
/IORQ ─┬──────────────┐ │ │
│ DD7 │ │ │
│ ┌──┬──┐ │ DD4.4 DD6.2 │ │
└14│ R│ 0│ │ ┌──┐ ┌──┐ │ │
+5В ──11°WR│ 1│ └─10│ 1│8 ───────4│ &│6──┘ │
┌─5/+1│ 2│6────── 9│ │ ┌─5│ │ │
│ ├──┤ 3│ └──┘ │ └──┘ │
│ │ │ │ │ │
│ └──┴──┘ │ │
└─────────────────────────────────────────┘
│
DD6.3 DD3.2 │
┌──┐ ┌──┬──┐ │
D13:26 ──10│ &│8─────13° R│ _│ │
D49:11 ── 9│ │┌─────12│ D│ Q°8──────┘
└──┘│ ┌───11/ C│ │
D13:28 ────────┘ │ ┌10° S│ │
D50:13 ──────────┘ │ └──┴──┘
+5B

The HLD signal is taken from the 28th leg of VG93, /IP - from VG93:35,
/IORQ - from Z80:20, and /bit7#FF - see below.

For turbo:

1. Disable D5:2 and D13:28 (D5:13)
2. Disconnect D15:1 from +5V
apply a /RFSH signal to D15:1 (D13:28)
3. Disconnect D13:6 from D1:8 so that there remains a connection between
D13:6 and the resistor connecting it to +5V.

By the way, AY-3-8910 (not YAMAHA!) also works poorly in the
turbo, like the VG93, so this modification will also solve the problem
brake AY.
I repeat: for normal operation of the UZH turbo, change the diode
VD2 in the controller circuit. If it is not replaced, most
turboloaders in the turbo will fail, since they use jp #3d30 to access
DOS routines. In the turbo, this same
VD2 greatly slows down the switching of ROM pages (DOS/BASIC).
As a result, the effects are familiar to everyone: the launched one hangs and/or
craps on the disk...

Here is a diagram for replacing the VD2 diode (according to the Pentagon scheme
controller):

As it is:

DD77(LL1) DD76(TM2)
┌──┐ VD2 ┌──┬──┐
│ 1│11 ──│<──┬───┬─────13│ │ │
│ │ ─┴─ │ │ │ │
└──┘ C3 ─┬─ │ │ │ │
─┴─ █ R13 └──┴──┘
│
DD78(AG3) │
┌──┬──┐ │
│ │ │12──┘
│ │ │
│ │ │
└──┴──┘

And how it should be:

DD77(LL1) LI1 DD76(TM2)
┌──┐ ┌──┐ ┌──┬──┐
│ 1│11 ───┬─────────13│ &│11───13│ │ │
│ │ ─┴─ ┌──12│ │ │ │ │
└──┘ C3 ─┬─ │ └──┘ │ │ │
─┴─ │ └──┴──┘
│
DD78(AG3) │
┌─────┐ │ Free element LI1 is in the circuit until
│ │12──┘ turbo operation.
│ │
│ │
└─────┘

and here, in fact, is the scheme for finalizing the controller
BETA-DISK-TURBO into BETA-DISK-TURBO-HD :)

BQ1: 16 MHz DD9
┌──┬──┐
┌──────┤█├───────┐ DD86:6───2│A0│ │
│ DD8.1 DD8.2 │ DD8.3 DD93:14──5│A1│Y0│4──> to DD76:3
│ ┌──┐ ┌──┐ │ ┌──┐ ├──┤ │
├1│ 1°2─┬─3│ 1°4─┼─5│ 1°6──────────3│B0│Y1│7──> instead of 2 MHz
│ └──┘ │ └──┘ │ └──┘ DD93:13──6│B1│ │ under revision
│ K43 │ K43 │ ├──┤ │ TURBO-VG
└──███──┴───███──┘ ┌─────1│ S│ │
│ ┌─15°OE│ │
DD5.2 │ ─┴─ └──┴──┘
+5V ┌──┬──┐│
├─13° R│ Q│9──────┴───── on the HD/DD microphone in
D7 (Z80:13)───12│ D│ _│ disk drive (see below)
D88:9 ───────11/ C│ Q°8── /bit7#FF
└─10° S│ │
└──┴──┘

Chips:
DD1: 1533КП11, DD2: 1533ЛЭ1, DD3: 1533ТМ2, DD4: 1533ЛЛ1,
DD5: 1533ТМ2, DD6: 1533ЛИ1, DD7: 1533ИЭ7, DD8: 1533Л 1,
DD9: - CUT OFF!

The signal from the DD5:9 modification going to the HD/DD microphone in the disk
gadfly does not need to be buffered (I have never buffered it, but
I have a 1m cable to the disk drive, and everything is OK). The HD/DD
mic itself is located on the motor board, just above the “HD”
hole in the disk (it is usually sealed). and the common wire usually goes to one leg of the microphone
, and the control
signal for the microcircuit is removed from the other. Here we give the signal
“HD/DD” to the second leg. Yes, now you HAVE to remove the stickers
from the disks (on 3.5" - stickers! Insanity..). If you are going to use
720K 3.5" disks (they don’t have an “HD” hole), in advance
pass the “HD/DD” signal through a 50..100 Ohm resistor,and
only then feed it to the mic in drive.

Actually, in the Pentagon this 16 MHz generator
would not be needed, but because... Almost all Pentagon drivers have a 556PT4 PLL
, so the circuit is given taking into account its presence in the
controller. If there is no PLL, then DD9:2 needs to be supplied
DD76:6, DD9:3 - DD86:6, and then you need to cut off DD76:6
from DD92:3.

How does it all work together?

The density mode (normal/high) is switched
by software, bit7 of the #FF controller port: bit7=0 - normal,
bit7=1 - high density. Fortunately, it so happens that
all programs that work with the disk always keep this bit
in the same state: zero. Having made the modification, you can
safely run the old programs, they will work with 360K-720K disks just as before
.
I must say, without a turbo it doesn’t work, because... the exchange rate
increases exactly twice (2 MHz
is supplied to VG93 instead of 1 MHz) - now it is more than 60K/sec. By turning on
the turbo mode when executing a program from DOS ROM,
we ensure that the Z80 still has about 112
clock cycles per exchange cycle and it, the Z80, works with the VG93 just as
at normal density.
and high density disks can fit up to 18 512 byte-sec
tors (1.44M format) or up to 10 1024-byte (non-standard
, but also 1.6M format). Thus, it’s easyread
MSDOS(PS/2) HD disks are read/written.

After modifying the turbo, it will always turn on during
disk operations, but only after the disk has had time
to spin up. If the exchange with the disk is at normal
density, the turbo mode can be turned off with the microphone
“TURBO/NORMAL” (interestingly, this was needed for one
only program: FUT by MI&DI). If the turbo was
turned on, it turns off while the disk is spinning up, and then
turns on again.
When positioning for modification, the TURBO-VG always goes
2 MHz, unfortunately, at a higher frequency the VGshk
does not work.
According to rumors, one of the two reserve contacts
of the 5.25" drive connector should receive a control signal
for the engine rotation speed. and my Mitsumi 3.5" both
backups don't go anywhere. So, I sent the "HD/DD"
signal through the 2nd backup pin (numbered as 4th on the
disk drive connector) - and it works fine for me, and on the PC.

P.S. All designations of the elements are given according to the Pentagon diagram
in which the Z80 address signals are designated A1-A16.
Unfortunately, there is no way to do without removing the drive casing,
but all the alterations in it are just one wiring.

P.P.S. The new turbo mode scheme was provided to me
by Roman Milyukov (2:4616/8.52) for which he is very gratefulthank you!

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Well, that's it. Goodbye, Kirill.