| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1012.1 | The cable is the hard part, though not impossible | YNOTME::WALLACE | | Tue Nov 13 1990 12:22 | 10 |
| > 1. Is it possible to buy a 720 Kb drive and connect without any
You'll need a case and power supply if it doesn't come with those, and (most
significantly) you will need a cable. The cable is Atari specific and is not
widely available, though some mail order houses have it.
> 2. Is it possible to connect a 1.44 Mb drive in the same way as
This requires a mod to the ST mother board (I don't know the details).
Ray
|
| 1012.2 | send E-mail if interested | MGOI01::FALKENSTEIN | so many girls, so little time... | Tue Nov 13 1990 12:35 | 6 |
|
I could provide you with both the cabeling pinouts (if you want to
solder it on your own) and the schematic for the 1.44MB modification.
Bernd
|
| 1012.3 | EXTERNAL FLOPPY ===>> USE DRIVERS | MUCTEC::HIERL | The beautiful MUCTEC Cluster | Wed Nov 14 1990 03:07 | 7 |
| To protect the expensive Atari Chips you should also use driver IC's
( I used SN7417 ) between Drive & Atari. If you need more info -
send a mail directly.
Hans
|
| 1012.4 | Soon I'll have more floppy's | UTROP1::VDBOS | | Thu Nov 15 1990 04:06 | 7 |
| Bernd, Hans,
Thanks for your offer to send me more info. I'll mail you both directly
to ask for the promised info
Peter
|
| 1012.5 | Second Floppy was cheap and easy | PWRHIT::ADAMS | beam me up | Tue Jan 29 1991 16:28 | 17 |
| Last weekend I stopped by the PC show in Marlboro Ma. While there I saw some
Epson 720k drives for $30.00 and 1.44m drives for $53.00. Also A 1.44 already
assembled into a 5 1/4 bracket with power cable and cable connector for $60.00.
The 1.44 drive was made by TEAC. I had heard that it would format out to 85
tracks 11 sectors no problem so I went for the TEAC even though I would not be
using the full 1.44m capability. I later found a booth selling cables for use
between the ST and standard 3.5in drives soooo I bought it, $15.25. Very nice
cable not a hack job. So all I needed was a power supply which I had at the
office in the form of an old leprechaun box. The 5 1/4 frame fit perfectly.
When I connected and powered up it worked fine. It did format out to 85 trks
11 sectors that gets me almost a meg on each floppy. I have used it quite a bit
over the last few days to break it in and have not seen any problems to date.
If you wanted to save a little more money I am sure that the $30.00 Epson would
work at least as well as the standard internal Atari drive and that would get
you everything but the power supply for under $50.00. I did not price external
drive boxes and power supplies (sorry) ;-(
Bob
|
| 1012.6 | | SUBURB::CUGLEYS | Just call me Katie | Fri Feb 01 1991 07:40 | 16 |
|
I want to buy a dbl-sided drive (3.5") , swap it with my internal
sngl-sided , and keep the sngl-sided as an external second drive.
What does this involve, physically and above all currency wise.
Also, if anyone knows where I can get the required bits'n'bobs (you
know ... discdrive, case , cables etc etc etc) and how much they cost.
[I'm talking UK here ... I'm in READING if it's not mailorder]
Thanks,
S.
|
| 1012.7 | if Atari drive, just swap! | UFHIS::BFALKENSTEIN | | Fri Feb 01 1991 10:44 | 14 |
|
Basicly there should me nothing about swapping the drive. The external
SS drive must be jumpered as Drive 1, the internal as Drive 0.
You need a original Atari floppy cable and some kind of adaptor (inside
the external case) to the Shugart standard edge connector (32 pins) at
the 3.5'' drive. You could buy a Atari floppy connector and solder a
ribbon cable to it or design a board for a nicer look. I'll mail you
the connector layouts of both if you want. That's all if you buy a
non-Atari second drive. If you buy a Atari DS drive, just swap the
drives and jumper them correctly, that's all. Formatting SW is designed
to handle both DS and SS.
Bernd
|
| 1012.8 | Look closely at the shape and position of the eject | UKCSSE::RDAVIES | I can't tryp for nots | Fri Feb 01 1991 11:00 | 7 |
| If your putting a different drive inside the case, the eject button may
not be the right shape AND THE CASE OF YOUR ST MAY NEED MODIFYING i.e.
cutting!
Check this out first and decide if you want to do it.
Richard
|
| 1012.9 | | SIEVAX::JAMIE | Having wrubble with your turds ? | Fri Feb 01 1991 13:25 | 2 |
| Simon, You're welcome to have a look at my machine to see what it looks
like before and after cutting! It's not bad at all.
|
| 1012.10 | Drive connection help needed. | CITYFS::SM | Not now, I'm eating my lunch!!! | Tue Feb 26 1991 09:49 | 22 |
|
I managed to purchase a Mitsubishi 3.5 720K drive (model MF353C-118M)
for a give away price , however I cant seem to get it to work properly.
I had problems using my external drive cable so I hooked up the drive
internally which still doesnt seem to work.
The symptoms are a follows:
Format works OK
I can write small files on a fresh disk but it doesnt seem
to work once the disk is above 10% full.
The system will boot off that drive Ok but If I connect an external
drive ( a commercial one that works ), the system just hangs.
There doesnt seem to be any resistor packs or jumpers on the drive
other than drive select.
Can Anyone help,
Desperate....
|
| 1012.11 | It can't handle the default step rate | GIDDAY::HIRSHMAN | GIGO: Garbage In, Gospel Out | Wed Feb 27 1991 01:43 | 44 |
| Let me guess - you bought it at Jaycar in Sydney, right?
I had almost the same experience when I bought one of these myself,
which is a pity because they're quiet and very solid mechanically.
The problem is the drives' step rate; they just can't hack it at 3 mS,
but if you poke the appropriate TOS stepping rate location to 6 mS they
work fine. In theory you can use an MF353C-118M on an ST if you set
the step rate every time you boot, and there are utilities that will do
this for you - up to a point. For example, DCFORMAT can write a boot
sector on a floppy that will set the step rates for drives A: and B: to
any legal values you like.
But this doesn't help for bootable games floppies, so in the end I
took the drive back and swapped it for some other things I needed.
As for the hang problem, first make sure that your good drive doesn't
have pull-up resistors that are less than 1K Ohm in value - although
this would be very unusual. The MF353C-118M's I've seen do have the
standard 1K pull-ups.
In any case, I suspect that it may be your ST and not the Mitsubishi
floppy that's at fault. The ST's floppy interface is non-standard at
the electrical level as well as at the physical connector level; there
are a few output lines that are unbuffered and two that have 47 Ohm
resistors in series with them. (I can't remember which signals off the
top of my head.) The lack of buffering is probably just cost cutting,
but I've never been able to work out even a semi-valid reason for the
resistors. What I can say is that they shouldn't be there and that
they can cause problems even with bog-standard Atari drives. I've seen
a couple of ST's - mine included - that wouldn't support two floppy
drives at all reliably until those resistors were shorted out.
If you feel competent to do it, I'd suggest you open up your ST and
look for two 47 Ohm resistors near the floppy cable socket. They'll be
colour coded yellow-violet-black-foo, where foo will be silver, gold,
red or brown. When you find them, either solder a wire across them or
remove them completely and put in insulated jumper wires or zero Ohm
resistors in their place. My ST has been running like this for nearly
two years without any problems.
Actually, I went a bit further than this and stuck in a 7417 buffer
chip to fix up the unbuffered signals as well. As a result, my ST can
now handle standard 5.25" drives with 150 or 330 Ohm pull-ups in them.
|
| 1012.12 | buffer the signals from the sound chip | BERN01::RUGGIERO | Markus Ruggiero, EIS/PS, Z�rich/Switzerland | Wed Feb 27 1991 02:25 | 27 |
| re .10
I had similar problems when I connected a 5 1/4" drive. The disks
formatted fine but after some time of use, when the chips got warmer, I
could only write about the first 100k.
Some of the drive signals in the Atari come directly from the soundchip
and are not buffered (I think it's drive select and side select). The
drive might be a too heavy load on them, especially when you connect
both drives. I think the formatter only puts its stuff onto the track
but does not verify it thus formatting is fine (seems to be fine!).
Check the terminator on the drives. Are they really removed? They might
look like an integrated circuit and sit on a socket.
Try to buffer the signals from the sound chip (just use a 7407. There
is an array of 0 Ohm bridges near the edge of the ST mainboard. In an
older design there used to be some T-shaped network that is now just
shortened out. You can easily intercept the signals there by removing the
short cut.)
Hope this helps
---markus---
|
| 1012.13 | Mitubishi drive probs.. | CITYFS::SM | Not now, I'm eating my lunch!!! | Wed Feb 27 1991 03:22 | 15 |
|
Hmmmm, sob, sob...
Yep , the drive comes from Jaycar alright!
I managed to get hold of a friends external drive and connect the
Mitubishi up where the "working drive" goes , same thing..
I dont think I want to put up with changing the seek rate so I think
I might take it back...
Ta
|
| 1012.14 | Schematic? | BIRMVX::LANE | Engineerus Digitalis | Thu Feb 28 1991 03:50 | 10 |
| re.11
Any chance of a schematic on how you buffered the floppy signals?
I have a 5.25" floppy that has the same problem.
Thanks in advance
Roger
|
| 1012.15 | here is the schematic (sort of) | BERN01::RUGGIERO | Markus Ruggiero, EIS/PS, Z�rich/Switzerland | Fri Mar 01 1991 02:49 | 51 |
| > Any chance of a schematic on how you buffered the floppy signals?
> I have a 5.25" floppy that has the same problem.
I'll try to draw and describe:
+----+
| |----- various signals +---+
|1772|----- pass here through ------------------+---------|
| | . inverters and are | | connector
| | . all buffered ------------------|-+-------|
| |----- | | | for
+----+ ------------------|-|-+-----|
| | | | internal
+----+ | | | |
|sound | | | | floppy
|chip|----------side 0 select--------------/L16/----|-|-|-+---|
| | | | | | |
| |----------drive 1 select-------------/L24/----|-|-|-|-+-|
| | | | | | | |
| | | | | | | |
| | | | | | | +---
| | | | | | |
+----+ | | | | | +---
| | | | | |
| | | | connector
etc. | | |
Both connectors are more or less just | | for
connected in parallel. Two lines from the soundchip |
go there UNBUFFERED. |
The following description of the physical location on | external
the main board are for the 1040 but I think one might |
find the appropriate places easily on others (Mega) | floppy
|
Just behind the connector for the EXTERNAL floppy is an |
array of zero Ohm bridges labeled from L15 to L25. I have +---
marked the ones we are interested in in the drawing above.
These bridges are located before the signals split. Intercepting the signals
here will buffer both ports. I just used a 7407. This chip includes 6 buffers.
Open the L16 and L24 and connect them as follows
+5V
1/6th |
7407 100k
from soundchip |\ |
----------------------| |----+------to floppy connector
|/
Please look up the pin assignment for the 7407
shortcut any unused INPUT of the 7407 to ground to prevent overheating of the
chip
|
| 1012.16 | Problems with PC720 floppy drive | COMICS::ADAMS | | Mon May 25 1992 23:34 | 35 |
|
Can anyone advise me if the problems in note 1012 & replies would
apply to a current configuration;
ie 520 STe 4Mb + External Floppy Drive = Power Computing PC720 with its
own external 5v power supply. (Disk is 4 months old)
I need to do some more testing, but have seen intermittent problems,
such as
"Drive B is not Responding" at various times, often during extraction
of archived files.
"Drive B is Hardware write protected" part way thro' a disk copy,
writing to B.
"Write error at ....." during a write to B. Diskette OK in Drive A.
Clicking on "Retry" has no effect, and "Abort" usually results in
what I believe to be Drive A hitting the end stop.
The only "fix" (so far) seems to be to power off/on and reboot.
The system appears to work fine with just internal drive A.
I've tried all the suggestions in the Power Computing booklet, other
than trying the drive on a friend's system, but I don't want to do
this in case it damages their system.
Could the drive be overloading the driver chips in my STe ??
Does the STe/Drive need terminating resistors/drivers ??
Maybe I should send the drive back to Power Computing.
Maybe I should have bought a Cumana drive.
What do the experts think. ???
/Brian.
|
| 1012.17 | Send it back | WIKKIT::BRADBURY | better to burn out.......... | Tue May 26 1992 14:04 | 7 |
|
I have a PC720B drive, when I first got it I experienced exactly the problems
you mentioned, I sent my drive back to Power Computing and I have had no
troubles with my replacement drive.
Colin.
|
| 1012.18 | Re .16. Power supply failed. | KERNEL::ADAMS | Brian Adams CSC-Viables '833-3790 | Wed Jun 03 1992 16:39 | 8 |
|
Got the drive back from Power Computing today, with a report that the
power supply had been found to be bad, so they replaced that part. The
drive itself was OK, apparently. I'll find out if all is well again,
when I get a chance to work on it tomorrow.
Brian.
|