ZX<->PC

I created a sublink of the interlink type - 10 wires, 5 in each direction.
But there is a problem with its intended use... You need 5 wires
a duplex or half-duplex connection with error protection. So that if one
computer sends something, then the other must necessarily accept it. Bytes should not
disappear or appear extra. The length of the transmitted data block does not matter and several blocks can merge into one or vice versa. I don’t need any
inventions like XYZ Momeds and others.

If someone can enlighten me on the topic of what ftp is and how it can be adapted
to the spectrum, then it will be very good.

Kirill

Tue Mar 16 1999, Kirill Frolov squeezed the keyboard, hoping that the following words would reach All:

KF> I created a subject link of the interlink type - 10 wires, 5 in each
KF> side. But there is a problem with using it for its intended purpose...
KF> You need a duplex or half-duplex connection with error protection
KF> over 5 wires. So that if one computer sends something, then the other must
KF> be sure to receive it. Bytes should not disappear or extra ones appear.
KF> The length of the transmitted data block does not matter and several
KF> blocks can merge into one or vice versa. I don’t need any inventions like XYZ
KF> momeds and others.

Oh! I want software for such nonsense! There are two computers standing next to each other - it would be a shame not to use them together!

[Team Kelly]
Hasta la vista.
Tim Kelly

... PGP Key Fingerprint = D4 CA 92 C2 EE 54 21 E1 01 E1 3E 2B 34 BF BC FC

KF>> each side. But with its intended use there is

TK> Oh! I want software for such nonsense! There are two computers standing next to each other - it’s a sin not to use TK together!

I haven’t come up with anything better than working with the Spectrum with TRD images on the PC. :-(
Now I’m trying to write software. Meanwhile, 5 wires seem
to me not enough and I want to connect using 8 wires...

Has anyone already connected or tried?

Kirill

What's the problem? Half-duplex with error protection can, in principle, be transmitted over
one signal wire... Are you “swimming” in the protocols?
(By the way, when you started these 10 wires, didn’t you think about how you
would use them, and why these 10 are needed? Yes, and also answer the question -
why exactly? 5? 5 - this is one way. And therefore, you don’t have any feedback? And if there is, then what is the problem? The length
KF> of the transmitted data block does not matter and several blocks can
KF> merge into one or vice versa.
So I don’t understand - what’s the problem?! Take any book dedicated to telecommunications and look at the section “Excessive noise-proof coding”,
as well as “Transmission protocols”.

KF> I don’t need any inventions like XYZ Momedov and others.
Do you want to invent something of your own? Go for it. Just answer two
questions: (1) why don’t you like XYZ, very convenient protocols? (2)
What, creating your own simple file protocol is a very difficult task?
Yes, and a related question - in general, what does the XYZ-protocols (the upper
level of the seven-level model) have to do with the lower-level protocols that
you are asking about?

KF> If anyonewill enlighten you on the topic of what ftp is and how it can
KF> be adapted to the spectrum, then it will be very good.
FTP - File Transfer Protocol. Protocol for transferring files via IP channels.
It is possible to attach it to the spectrum, but is it necessary? Do you have an IP channel in this “link” of yours? Why did he surrender to you there, can you find out?

P.S. No offense? It’s just that it all looks very weird... And funny...

Good luck! Evgeny.

■ The night is shorter than the day... The day will kill me... The world of illusions burns down in it. (C) Aria.

EM> Do you definitely want to invent something of your own? Go for it. Just answer
EM> two questions: (1) what don’t you like about XYZ, very convenient
EM> protocols? (2) is it a very difficult task to create your own simple file protocol
EM>?

It works quickly. There are almost no problems with the protocol, but the Spectrum works
slowly. Noise-proof coding cannot be used at all. Now
I'm thinking about switching to more complex hardware - RS232 at 115200 baud. At least on the Spectrum everything will be much faster.

EM> FTP - File Transfer Protocol. File transfer protocol via
EM> IP channels. You can add it to the spectrum, but is it necessary? Do you
EM> have an IP channel in this “link” of yours? Why did he surrender to you there, can
EM> find out?

EM> P.S. No offense? It’s just that it all looks very weird... And
EM> funny...

I need to work with .TRD .FDI .IMG files on a PC on the Spectrum.
Create and delete files and directories.
Now there is already a 50% working program, but the speed is low - disk
in 180 seconds transmitted.

Yes, and the question torments me - for example, I will connect via 8 wires (actually
8 given + several controls). The transmission direction will be switched
in the Spectrum based on a signal from the PC, and the PC will programmatically processdirection signal
from the spectrum. But how can I make it so that if any computer
wanted to transfer a few bytes, then it would transfer them?

Kirill Frolov.

Wednesday March 24 1999 01:10, Kirill Frolov ─── Tim Kelly:

KF> Meanwhile, 5 wires already seem to me to be not enough
KF> and I want to connect with 8 wires...
8 will not be enough for you until you start thinking before do...
(By the way, where are you putting all this stuff?)

KF> Has anyone already connected or tried?
I connected. THREE wires. It works.

EM> I connected. THREE wires. It works.

How long does it take to transfer the disk?
How does it work in the background under Windows?

Where do you connect it? If in LPT, then how come it hasn’t burned out yet?

How bug-free? That's when my mail is unpacked MAS_ZXLINK
it glitches (Windows is to blame for everything) and errors occur due to timeouts.

Kirill Frolov. [ZX]

KF> And you probably have a hardware transceiver.
Only an LPT port... :))

KF> Yes, and the question is bothering me - for example, I will connect via 8 wires (in fact
KF> there are 8 given ones + several controls). The transmission direction will
KF> be switched in the spectrum based on a signal from the PC, and the PC will program
KF> process the direction signal from the spectrum. But how can I make it so that
KF> if any computer wanted to transfer a few bytes, then it would transfer them?
??? I don't understand. If he wants to transmit Spectrum, then there is no problem... Oh, I understand.
Did you mean PC? Then, IMHO, it’s worth creating another signal (an additional
wire, or combining the function with some other wire) - a request
transfer from the control center.
What else? Here it is. Until you set up interrupts (for example, when using com ports on PC and Spectrum), you will not be able to transfer bytes at absolutely any time. Maximum - one of the computers issues a request for
reception/transmission, and waits for another...

EM> LPT port only... :))

Do you have one in each direction? :-( )
Which means everything is tied up for the time being - sax. It won't work with Windows.

EM> What else? Here it is. Until you create interrupts (for example, when
EM> using com-ports on PC and Spectrum), you will not be able to transfer
EM> bytes at absolutely any time. Maximum - one of the computers
EM> puts out a request for reception/transmission, and waits for another...

That's it. And the PC slows down more than the spectrum!
How about you ON ONE WIRE? It goes to ACK, and you take the time from the timer
?

But IMHO you have one serious problem - you need to send confirmation.

Kirill Frolov. [ZX]

KF> How long does it take to transfer a disk?
That’s what it is, that is, in quite a long time (at least 5-10 minutes)*

KF> How does it work in the background under Windows?
But not at all. Since the reception/transmission is in synchronous mode. And in
serial code.

KF> Where do you connect? If in LPT, then how come it hasn’t burned out yet?
Yes, it hasn’t burned out yet. And it shouldn't burn. :). You have strobing. And the strobe is a great thing. If I had a strobe signal, it would be just a fairy tale, and
not a program.

06 Apr 99 08:33, Evgeny Milun wrote to Kirill Frolov:

EM> I understand, do you have a unidirectional or bidirectional channel? If you

5 wires in each direction, now. I don’t know what will happen next.

EM> I managed to connect “extra” wires to Kempston on the Spectrum, but on PC
EM> you did it.

I didn’t understand the question. But there are 5 Kempston bits as input on the spectrum,
on the PC - in LPT there are exactly 5 input signals. Weekend on the spectrum 5 low
bits of the centronix interface, on the PC again LPT.

KF> Do you have one in each direction? :-( )
Agym.

KF> Which means everything is tied up for the time being - sax. It won't work with Windows.
It will, but not like that anymore. At first I have something like headshaking going on there, and
the PC adapts to the speed of the spectrum and to its own speed.

KF> That's it. And the PC slows down more than the spectrum!
KF> How about you ON ONE WIRE? It goes to ACK, and you take the time from the
KF> timer?
No. It means so. I use width modulation - when the information
is carried by the duration of the pulse. When headshaking, the PC measures the duration "1",
the duration of zero - duration_1*2. Well, the transmitter makes a request for transmission and waits for confirmation from the receiver. When an acknowledgment
is received, 8 bits are transmitted sequentially. Then the transmitter issues a request at the end of the session and waits for confirmation. All. Now everyone does their own thing.
The only inconvenience is that both PC and Spectrum must know exactly when and who will transmit what and how much...

09 Apr 99 you wrote here:

KF> I didn’t understand the question. But there are 5 Kempston bits as input on the spectrum,
KF> on the PC - in LPT there are exactly 5 input signals. Weekend on the spectrum 5
KF> low
KF> bits of the centronix interface, on the PC again LPT.

A special iron 8-bit port must be made so that it is as fast as possible.