Quorum 128 & FDD 3.5
ZXNet echo conference «hardware.zx»
Hello BotzMan
possible. connects exactly the same as 5.25.
just keep in mind that 3.5 will be disk "B". so that it becomes “A” you need to look for it
jumpers on the flop, or turn over I don’t remember which wires are on the cable.
and this, the disks must be 720k (or seal the hole at 1.44)
Hello, All
Yesterday I got my hands on a live "Quorum 128" with a 5.25 disk drive and a monitor
"Electronics 202"! Everything is alive, in excellent condition, BUT: only one floppy disk, and
it's slightly battered. In this regard, the question is: is it possible to connect a disk drive from a PC?
(there are several - starting around 1999) 3.5 inches to Quorum, and at what
is this done in the diagram?
:confused:
Hello BotzMan
Bot> Where can I find the circuit?
I'll try to post it here tonight.
Hello BotzMan
Bot> ... question: is it really possible to connect a disk drive from a PC (there are several -
Bot> starting around 1999) 3.5 inches to Quorum, and according to what scheme
Bot> is this being done?
Bot> :confused:
Place a connector for a 3.5" drive on the cable and you can connect.
Modern 3.5" drives do not have access switches and when directly
connected to the loop are recognized in the system as B: devices.
To install them in the system as A:, you need to swap 10 and 12 in the loop
conductors.
Usually, for this purpose, on IBM cables, twisting is done at the end of the cable.
If you do not twist and the power supply will pull both drives, then by default
5.25" would be A:, 3.5" would be B:.
It’s most convenient to make a switch on the cable that will allow you to change places
disk drives
To do this, you need to cut conductors 10 and 12 on the loop and connect them to the gap
toggle switch for two positions/two directions.
For 3.5" floppy disks, it is necessary to seal the hole that defines
recording density.
Hello BotzMan
Bot> My gratitude knows no bounds!
Catch the diagram.
I think there will be questions. I'll try to answer.
File: qu128mp.zip http://zx.pk.ru/attachment.php?attachmentid=2113
Hello BotzMan
Bot> Another question has appeared, even two:
Bot> 1. Is there an AY case, can I really pick it up?
There is a connection diagram.
You just need to be able to hold a soldering iron in your hands :)
Bot> 2. Can you make a real flop from TRD?
Yes, it’s possible, only better on a computer with WIN98, and even better with MS-DOS.
Utilities can be found at http://trd.speccy.cz
Hello caro
car> Catch the scheme.
car> I think there will be questions. I'll try to answer.
thanks for the diagram!
I have a question :)
where does 16MHz come from? Is there quartz in there?
I’m just now also slowly connecting ym2149 (thnx to CHRV :))
I found a circuit, but on it 1.778 MHz are formed by LA3, a 470 pF capacitor and
330 Ohm resistor (http://www.irls.narod.ru/sncl/ay002.htm, at the end)
I don't know what would be better...
Hello Eltaron
Elt> thanks for the diagram!
Elt> I have a question :)
Elt> where does 16 MHz come from? Is there quartz there?
Elt> I’m just now also slowly connecting ym2149(thnx to CHRV :))
Elt> found a circuit, but on it 1.778 MHz are formed by LA3, a capacitor on
Elt> 470pF and a 330 Ohm resistor(http://www.irls.narod.ru/sncl/ay002.htm, in
Elt> end)
Elt> I don’t know what would be better...
"Quorum 128" is made on the basis of ULA KB01-VG1 produced by the Mikron plant.
And this microcircuit is made, in turn, based on the Baltic circuit design,
that is, the clock frequency of the video generator is not 7, but 8 MHz.
Therefore, the basic clock generator is powered by 16 MHz crystal.
The circuit, of course, can be made on LA3, but given the spread of parameters
elements, I think it will not be possible to achieve the exact frequency value.
A quartz oscillator with a divider provides obviously high accuracy.
By the way, branded Spectrums have quartz at 17.7345 MHz
and the clock frequency supplied to AY is 1.77345 MHz.
Hello caro
The drive has come to life! Thank you! All that remains is to switch the wires so that it becomes A.
Hello BotzMan
For reference: modern disk drives do not actually have a switch
samples, but if you look carefully, these “switches”
there are drops of solder in specially designated areas. At least ALPS
managed to re-solder in such a way that it is defined as A: without problems and without twisting
plume. The second drive hangs on the same cable, but is not soldered, it is determined
like B: