Can I use 1.2 mega drives? (fwd)

10 Aug 98 Andrij M, hoping that everyone will read, wrote:

AM> And this question interests me. Is it possible
AM> to use 1.2 mega drives on
AM> Spectrum? I tried formatting,

You meant HD 5.25 ~ floppy disks, but formatting them
like regular DDs? That's what I do. But for this
you need a good imported drive. I have a Mitsumi D509V3,
it is switched by a 1.2/720 jumper. It’s in position
720, and no matter what disk you put in it, it works with any.

2All: did you see that I posted here information from AXLR about the
1.44M format on Spec? He made it for himself a long time ago.

All the best.
Roman.

╨ Reply to Roman Milukov's letter -> Andrij M
╨ Subject: is it possible to use 1.2 mega drives? (fwd)

RM> 2All: did you see that I posted here information from AXLR about the
RM> 1.44M format on Spec? He made it for himself a long time ago.

I personally haven’t seen it, but I really want to see it.

See you. Jan Zagorskikh.

--------------------------------
(Continued.)

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───> on DD76:3
│ ┌──┐ ┌──┐ │ ┌──┐ ├──┤ │
├1│ 1°2─┬─3│ 1°4─┼─5│ 1°6──────────3│B0│Y1│7───> instead of 2MHz
│ └──┘ │ └──┘ │ └──┘ DD93:13──6│B1│ │ under revision
│ K43 │ K43 │ ├──┤ │ TURBO-VG
└──███──┴───███──┘ ┌─────1│ S│ │
│ ┌─15°OE│ │
DD5.2 │ ─┴─ └──┴──┘
+5V ┌──┬──┐ │
├─13° R│ Q│9──────┴──── to the HD/DD microphone in the drive
D7(Z80:13)───12│ D│ │ (see below)
D88:9 ───────11/ C│/Q°8── /bit7#FF
└─10° S│ │
└──┴──┘
Microcircuits:
DD1: 1533KP11, DD2: 1533LE1, DD3: 1533TM2, DD4: 1533LL1,
DD5: 1533TM2, DD6: 1533LI1, DD7: 1533IE7, DD8: 1533L 1,
DD9: 1533KP11
Any microcircuit except DD8(L 1) and DD9(KP11) can be
replaced with a similar one of the 555 series, this will only be reflected
in the load on the power supply.
Old signals going to DD76:3, 2 MHz on TURBO-VG - CUT OFF!

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

Actually, in the Pentagon this 16 MHz generator would not be
needed, but because... Almost all Pentagonists have a PLL at
556PT4, then the circuit is given taking into account its presence in
the controller.
If there is no PLL, then DD76:6 must be supplied to DD9:2, DD9:3 -
DD86:6, and then DD76:6 must be cut off from DD92:3. If there are still 2 LE1 elements left free, you can not install L 1, but
try to assemble a 16 MHz generator on them.

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 turned out thatall
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 just as before
with 360K-800K disks.
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 in the same way as at the usual density.
and the high density fits up to 18 512-byte sectors on the disk (format 1.44M) or up to 10 1024-byte
(non-standard, but also format - 1.6M). Thus,
MSDOS (PS/2) HD disks are easily read/written.
After the turbo has been modified, 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 using the "TURBO/NORMAL" toggle switch (interestingly, this was needed for one and only
program: FUT by MI&DI). If the turbo was turned on, it
is turned off while the disk is spinning up, and then
turns on again.
When positioning for revision, TURBO-VG always goes
2 MHz, unfortunately, at a higher frequency the VGshk does notworks.

According to rumors, one of the two backup contacts of the connector
of the 5.25" drive should receive a signal to control the speed
of the engine rotation. But on my Mitsumi, both backup ones don't
go anywhere. So, I sent the "HD/DD" signal through the 2nd backup
contact (numbered as 4th on the disk drive connector), - and
it works fine for me, and on PC.

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

All the best.
Roman.

YZ> Personally, I haven’t seen it, but I really want to see it.

Probably lost somewhere.
I repeat:
--------------------------------
(c)1998 AXLR
────────────────────────────
I've been meaning to publish the results of my work for a long time, but
everyone got around to it... but the solutions presented here have
passed the test of time, and that's good.

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 scheme for the Pentagon - collect it. The turbine diagram for the Leningrad clones is not given here due to the high
complexity of setting it up.
So, even if you already have a turbine, you will have to
finish 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 copies of KR1818VG93, namely 1993 and later
years of production, do not work well in the turbo. and this doesn’t seem to affect the quality of the exchange with the disk (they didn’t specifically test it), but who knows, VGshku. By the way, the VG93 glitches in the turbo are most noticeable in mytest ROM...
It would be best to provide a complete turbo diagram for
Pentagon, but with modifications (the original is from Online#02,
it seems):
DD1 +5V
┌──┬──┐ │
clk (3.5 MHz) ────────────────────────────2│A0│ │ █K47
DD2.1 +5V ────5│A1│ │ │
┌──┐ ├──┤Y0│4──┴───>Z80:6
┌2│ 1°1───────────────┬────3│B0│ │ K10
7 MHz ────────┴3│ │ ┌──────6│B1│Y1│7─███──>Z80:24
└──┘ │ │ ├──┤ │
+5V DD3.1 ┌────────1│ S│ │
│ ┌──┬──┐ │ │ │ ┌15°OE│ │
DD4.1 ├─1° R│ │ │ │ │ ─┴─ └──┴──┘
┌──┐ ┌───2│ D│ │ │ │ │
D15:3 ────1│ 1│3──────3/ C│/Q°6┘ │ │
D15:6 ────2│ │ │ └─4° S│ │ │ │
└──┘ │ └──┴──┘ │ └──────────────┐
│ └──────────────┐ │
DD4.2 └───────────────────────────┐ │ │
┌──┐ │ │ │
/bit7#FF────4│ 1│6────┐ │ │ │
D76:9 ──────5│ │ │ │ │ │
└──┘ │ │ │ │
+5V DD5.1 │ DD4.3 "NORMAL" │ │ │
│ ┌──┬──┐ │ ┌──┐ S1 ││ │
HLD ──┬──1° R│ │ └─13│ 1│11───── \ │ │ │
│├─2│ D│/Qo6────┬─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│ └──┘ │ └──┘ │
│ │ │ │ │ │
│ └──┴──┘ │ │
├─────────────────────────────────────────┘
D15:2 ┬────────────────────┐ │
│ │ +5В DD3.2 │ DD2.2 │
│ │ │ ┌──┬──┐ │ ┌──┐ │
│ │ ├13° R│ │ └─5│ 1°4───┘
└─────12│ D│ Q│9───────6│ │
└───11/ C│ │ └──┘
└10° S│ │
└──┴──┘

Сигнал HLD берется с 28йlegs VG93, /IP - with VG93:35, /IORQ
- with Z80:20, and /bit7#FF - see below.

By the way, AY-3-8910 (not YAMAHA!) also works poorly in a
turbo, like VG93, so this modification will also solve the problem
brake AY.

I repeat: for normal operation of the turbo, UZH O change 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 switching ROM pages (DOS/BASIC). As a result
- the effects are familiar to everyone: the neglected one hangs and/or craps on the
disk...
Here is the diagram for replacing the VD2 diode (according to the Pentagon circuit
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 LI1is in the diagram
│ │ │12──┘ modifications to the turbo.
│ │ │
└──┴──┘

(To be continued.)

All the best.
Roman.

RM>
RM> Probably got lost somewhere.
RM> I repeat:
RM> --------------------------------

[skip]

Cool scheme. Only one question arises:
Are there programs for this? At least read HD discs.

See you. Jan Zagorskikh.

16 Aug 98 Yan Zagorskih, hoping that Roman Milukov would read it, wrote:

YZ> Cool scheme. Only one question arises:
YZ> Are there programs for this? At least read HD
YZ> disks.

AXLR slightly adjusted the usual turboloader for this purpose. In this way, he
reads/writes to MS-DOS disks.
But the disks must be formatted on the PC. From lack of information. :(

2All: Who knows the MS-DOS format? We need information to write a formatter.
It’s the track structure that interests us! Please, more about this!
Attention! Let’s talk about it!

We are planning to make a driver for NeOS. It would be possible for is-dos, but we have it here
nobody really knows...

All the best.
Roman.

At 09:37, Monday August 17, 1998 there was such a thing that
Roman Milukov wrote a letter to Yan Zagorskih:

RM> It is planned to make a driver for NeOS.
Do you need a dock? One of these days I can upload it, and in the echo, I think everyone will be interested.
And not only about disk drivers, but also about other drivers (not about all of them, though, for now).

With respect, Roman aka Megus of Brainwave Tracks.

[Team ZX-Spectrum] [Team Iron Maiden] [Team Die Krupps] [Team Guitar]