ZX+Hayes: something similar on the FAQ... :)

================== begin of file "ZX+Hayes.W" =====

╔══════════════════════════ ════════════════════════ ════════════
║Saved for History Felix Knajzev (2:5030/827.9)
╠══════════════════════════ ══════════════════════ ══════════════
║Apiya : .NETMAIL
║From: Felix Knajzev (2:5030/827.9)
║To: Kirill Frolov (2:5030/827.2)
║Subject: "Hayes on the Spectrum without glitches"
║Date: Sunday 7 November 1999
║Time: 16:06:37
╚══════════════════════════
Greetings, oh venerable Kirill!

[Friday 5 November 1999] at [04:23:06] Kirill Frolov wrote a
letter to Felix Knajzev.
They discussed the topic "Hayes on the Spectrum without glitches." Let's continue
what we started...

============================================================================================

KF> For more than three months now I have been using the hayes-compatible
KF> modem
KF> Sportster 14400. Of course, this modem has good
KF> capabilities. And the main thing
KF> is access to FIDO. But unfortunately,
KF> was not without problems. Quite often
KF> strange phenomena are observed: a sudden breakdown in communication (hangs up
KF>) right during
KF> the exchange, hangs up when dialing, hangs (until
KF> you turn off the power to the entire
KF> computer nothing is impossibledo), inoperability in

What year is your Sprat? If it's from 1995, then you're guaranteed to be stuck. :) See for yourself:

================== begin of file "14400_0 .i" =====
┌───────────────────── ────────────────────── ────────────────
From : Nick Mesheryakov
To: Pasha Ezoff MSG #99 01-Jul-98 09:27
Subject: modem hangs
└──────────────────────────
Beer drinkers greet you, O Pasha!

This vile libel is nothing more than a response to a letter
from .

PE> Here problems with usr14400 int were discovered. Everything works fine in the
PE> processor, but at some point during initialization it crashes violently and
PE> only a power reboot helps. How can I wean the modem from doing this?
PE> It starts using at&f1.
There were rumors that robotics were either 95 or newer, which had just such a bug. The treatment was by purchasing a normal modem :(

Actually, that's all...
Nick Mesheryakov (c_t...@party.spb.su)

... I am my own sky and moon...
-+-
+ Origin: Fifteen people on a dead man's chest! (2:5030/462.11)

================== end of file "14400_0 .i" ==================

Andmore...

================== begin of file "14400_1 .i" =====
┌───────────────────── ────────────────────── ────────────────
From : Alex Romanov
To: Pasha Ezoff MSG #56 01-Jul-98 18:39
Subject: modem hangs
└──────────────────────────── Hello Pasha!

Tuesday 30 June 1998 18:06, Pasha Ezoff wrote to All:

PE> Here problems with usr14400 int were discovered.
If you do not touch the DTR, then it does not hang.
You need to write Dial_Terminate ~| , and not as by default v''^'|

Alex.

-+- GoldED/2 2.50+ launched under OS/2 in St. Petersburg.
+ Origin: MAXIMUM/2 BBS 23-07 583-5390 28.8Kbps (2:5030/557.17)

================== end of file "14400_1 .i" ==================

And finally... :)

================== begin of file "14400_2 .i" =====
┌───────────────────── ────────────────────── ────────────────
From : Aleksey Romanov
To: Pasha Ezoff MSG #70 02-Jul-98 07:46
Subject: modem hangs
└──────────────────────────
Hello to you, dear Pasha!

I’m sitting, not bothering anyone, and suddenly I see Pasha Ezoff writing to All...

PE> Here problems with usr14400 int have surfaced. Everything works fine in the
PE> Miller, but at some point during initialization ithe hangs himself cruelly and
PE> only a nutritional reboot helps. How to wean the modem from this
PE> thing? Init by at&f1.

In the terminal:

AT&F1
ATX3&W

And initialization by ATZ.

PS. Recording (&W) and ATZ is not necessary, but it’s more convenient.

It helped me, as far as I remember.

ICQ: 6868924 meta...@metalnet.hypermart.net -= Alexey Romanov =-

-+-
+ Origin: A8 94 73 5D 66 DE 3D 3C 4A AC 68 0E E1 F4 F2 AE (2:5030/586.9)

================= end of file "14400_2 .i" ==================

At what speed do you set the com port in Melon?
This program does not allow more than 9600 *reliably*
work.

Power (+5V) to the modem must be supplied directly from the place
on the main board of the computer where it (power) comes from the
power supply unit. :) Sorry for the taftology. :) Wires for this must be
*minimum* length and cross-section of at least 1mm.kv!!! Directly on
the slot for the modem, solder an electrolytic capacitor (for
+5V, preferably tantalum, type K52-1V. or K53 series)
capacitance
47...220 μF.

KF> TURBO mode...
KF> The modem is connected according to the Kondratieff circuit. Software used -
KF> Melon 1.80
KF> Until some time, I attributed all these glitches to the
KF> program, explaining all these
KF> phenomena by the imperfection and crookedness of Melon 1.80, but in

You yourselfcrooked. :) Normal software. True, only version
1.80+ (aka the latest) is free from most of the glitches.

!!! Melon needs to be launched from the boot, which, before launching
BASIC programs, does:

======
LD IY,23610
RES 4,(IY+1)
====================

If this does not happen, then Melon’s glitches are
guaranteed, especially during dialing (the program just
freezes).

KF> as a result Long-term
KF> observations (daily connections) I came to a different conclusion.
KF> Almost all glitches are to blame for the excessive criticality of the
KF> modem itself to
KF> control signals. This means that to completely eliminate
KF> glitches you will need to
KF> maintain all the timing parameters of the signals with high
KF> accuracy. Exactly
KF> fulfilling this condition gives the Spectrum
KF> user great difficulties
KF> (you have to select capacities long and hard).

And where have you already placed them?

KF> The solution to the problem is simple: you need to find the ISA bus standard and
KF> according to it
KF> assemble control signal generation circuits.

There is no need to look for anything. I thought so too some time ago.
I was wrong. All your problems are most likely caused by a not very
correct connection of the modem to the computer or problems *with the*
modem itself. So, try the following:

1. Modem neededIt is *necessary* to connect to the computer bus with conductors of the *minimum* possible length!!! 10cm is
the maximum!!! Ideally, if the data bus is fed to the modem as a “ribbon” (like
a cable for a disk drive), in which the signal
conductors go through one with the conductors of the common wire.
The number of conductors, of course, doubles :(,
but at the same time the noise immunity increases significantly.

2. Between addresses A8, A9, A10 and the modem, install (at each
address) two in series included gate 555(1533)TL2
(Schmitt trigger). The TL2 itself (you will need one case)
place in close
proximity to the modem! Ideally, solder directly on the slot.
(This point is recommended to be implemented last, if
nothing else helps. :)

3. “Decouple” the modem data bus and computer using a buffer.

================== begin of file "buf4mod .C" ==================
(imported 74LS245 work better than our 555AP6)

So, how to connect a buffer: +5Bo
K555AP6 ┌───────┴┐
__ ┌─────────┐Scorpion (74LS245) │8Rx 4.7K│ modem
B18/RD LL1 │13┌──┐11 │┌──┬───┐ ┌──┬──┬──┒ >─────────────o──┤1 ├─ ││D0│b6 ├─>─2┤A0│BF│B0├18─o┼┼┼┼┼┼┼──>│a9 │D0│
____ 12│ │ ││D1│b7├─>─3┤A1│ │B1├17──o┼┼┼┼┼┼──>│a8 │D1│
B17/IORQ 1┌──┐3 ┌─┤ │ ││D2│b8 ├─>─4┤A2│ │B2├16───o┼┼┼┼┼──>│a7 │D2│
>────────┤1 │ │ └──┘ ││D3│b11├─>─5┤A3│ │B3├15────o┼┼┼┼──>│a6 │D3│
A24/A4 2│ ├──o───────┐││D4│b12├─>─6┤A4│ │B4├14─────o┼┼┼──>│a5 │D4│
>────────┤ │ │4┌──┐6 │││D5│b10├─>─7┤A5│ │B5├13──────o┼┼──>│a4 │D5│
__ └──┘ └─┤1 ├─ │││D6│b9 ├─>─8┤A6│ │B6├12───────o┼──>│a3 │D6│
B19/WR ЛЛ1 5│ │ │││D7│b3 ├─>─9┤A7│ │B7├11────────o──>│a2 │D7│
>────────────────┤ │ ││└──┴───┘ ├──┤ ├──┤ └───┴──┘
ЛЛ1 └──┘ │└───────────1┤T │ │+U├20─o+5B
│ ├──┤ ├──┤
└───────────19oOE│ │0V├10─┐
└──┴──┴──┘ ▀▀▀

================== end of file "buf4mod .C" ==================

Питание на ls245 надо подать *короткими* проводами с сечением
жилы не менее 0.5мм.кв. // ногам 10 и 20 (питание) повесить
блокировочный керамический конденсатор от 0.1мкФ до.... :)

!!! Саму МС буфера надо расположить максимально близко к плате
компьютера (процессора), т.е. чтоб проводники шины данных (и питания) от
процессора до буфера были _минимальной_ длины! После буфера до
модема - до 25 см. Опять же - рекомедуется "ленточка, через один сgeneral."

KF> COMRADES SPECTRUMISTS! If anyone has this information,
KF> share it with everyone!

=============================================================================

KF> It's started again!!! ;-)

Please, transfer this to ZX.SPECTRUM!!! And call THIS what it is! FAQ.
:)

Sincerely, Felix.

[I ZX]
-+- Lara_Croft_v4.40
+ Origin: Was there, but sailed... (2:5030/827.9)

================= end of file "ZX+Hayes.W" =================================

Sincerely, Felix.

[I ZX]

26 Nov 99 16:54, Felix Knajzev wrote to All:

FK> Power (+5V) to the modem must be supplied directly from the place
FK> of the main board of the computer, where it (power) comes from the
FK> power supply unit. :) Sorry for the taftology. :) Wires for this must be
FK> *minimum* length and cross-section of at least 1mm.kv!!! Right on

What kind of modem is this? Electric iron as soon as possible.

FK> solder an electrolytic capacitor in the slot for the modem (for
FK> +5V, preferably tantalum, type K52-1V. or K53 series)
FK> with a capacity of 47...220 μF.

The modem has its own. And all these capacitors from the glucodrome are in the computer itself.

FK>> hang up

KF> Yes, you are bending the wires....

Here, after all, what is the matter... See the underlined above. I wrote
how it SHOULD be according to all the rules for wiring power buses for TTL digital circuits.
I myself, more than once, stepped on this rake and ended up with a buggy design.
Why do others need this?
Let them do it as I wrote (and in smart books) and everything will be ok/o.b.
You know how buggy Dallas was for me because to the buffer
(ls245), to which it (and the entire TR-DOS) was connected, power (+5V, 20th leg)
was supplied by the thinnest printed conductor (0.5mm) only ~2.5 cm long.
Duplicating this conductor with a thicker wire cured the glitch by 100%.

p.s. The question “about thickness” (any other sizes :) is closed.

FK> books) wrote and everything will be ok/o.b. You know how
FK> Dallas was buggy for me because the buffer (ls245) to which it (and the whole
FK> TR-DOS)
~~~~~~~
The whole _BETA-DISK_ is not one chip.

FK> was connected, power (+5V, 20th leg) was supplied the thinnest
FK> printed conductor (0.5 mm) with a length of only ~2.5 cm.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Well, there you go. Now calculate the cross-sectional area of ​​your conductor. There's much less of any wire there. Yes, and the skin effect
can appear ;-/

FK> Duplicating this conductor with a thicker wire cured the glitch
FK> by 100%.

Well, the wire is round, its area is much larger.

Kirill Frolov. [ZX]

That is enabling hardware flow control...

FK> There were rumors that robotics either 95 or newer had just such a bug. It was treated by buying a normal modem :(
By the way, nothing. Now I have a similar device... On my Scorpe everything
works perfectly, on Scorpe with a smook - a rake after a maximum of 20-30 seconds.
I'm still sorting this out, but the problems seem to be in the computer itself, and not
in modem.

Good luck! Evgeny. (Aka 2:5057/18.73)

■ The night is shorter than the day... The day will kill me... The world of illusions is burning in it.