Message for Simbo 1040 STE internals

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chance227
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Message for Simbo 1040 STE internals

Postby chance227 » Thu Feb 22, 2007 3:01 am

Hi Simbo

Have you had the chance to open up a 1040 STE later series 1990 +
system and check out the internals ( chipsets )
I have noticed that the later series came out with 4 brass support lugs on the casings, and were fitted with AJAX HD Diskette chipsets with 8 mhz crystals.

My question is if the crystals were replaced with 16 mhz crystals would they support 1.44 floppys without any other mods?

The Units in question all have X at the start of the units Serial numbers
eg: X 123456789 and I have 2 unit at the moment for testing.

Any help or info would be great

Chance227

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Postby Dew-It » Thu Feb 22, 2007 4:19 am

You could probably try a 1.44 drive with it. You would have to twist the cable. Simbo would know better than me. Did'nt know they put Ajax chips in 1040STe. 8O

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Postby chance227 » Thu Feb 22, 2007 4:31 am

I thought the same thing ( Ajax chips in a 1040 STe)
They are 100% AJAX chips as I have collected about 8 - 10 at home for spares. I'll post a pic when I get a chance

chance227

simbo

Postby simbo » Mon Feb 26, 2007 1:32 pm

yes and no

let me know the number of the chip and ill get a look at
its datasheet to know more

simbo

Postby simbo » Thu Mar 01, 2007 11:29 am

http://www.atari-forum.com/viewtopic.php?t=7687

i found this topic from a year or two ago

its all about putting a second floppy in an st
ignore this
the real info is in what you need to do to the cable

just a few joins and cuts to get a internal drive a and external drive b
1.44
as for the ajax chip

ye you can just change the crystal {its clock} by using a doubler stage
made from logic gates like xor or and.. {1chip}
no need to change the actual crystal

if you need details let me know

but type Xor gate clock doubler
into google and youll get some examples

this approch is by far the best and works
people moan on about just modify the drive unit
i say perminantly modify the atari then even if
the drive again fails you can plug in ANY pc sytle drive and it will DEFINALTY work
Last edited by simbo on Mon Mar 05, 2007 10:42 pm, edited 1 time in total.

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Postby MiggyMog » Thu Mar 01, 2007 9:09 pm

One day I will put my other STE back together and plug the HD drive in to the Exxos mod I bought a few months back :-)

I'm sure it will cause a Small Pyrotechnics show though!

BTW One of them has a Non WD drive chip, I take it this is an Ajax?
('< o o o o |''| STM,2xSTFM,2xSTE+HD,C-Lab Falcon MK2+HD,Satandisk,Ultrasatandisk,Ethernat.

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Postby chance227 » Thu Mar 01, 2007 11:38 pm

Hi there MiggyMog

" BTW One of them has a Non WD drive chip, I take it this is an Ajax?"

If you see VLSI on the Chip itself it is NOT a AJAX chip, Ajax chips have Atari stamped on them with a Cxxxxxxxxxx part no on them if my memory serves me well.
A VLSI chip will support H/D disk drives 1.44, but not as well as the AJAX chips
I am hoping to post a image of this STe internals this weekend for all concerned, as I suspect this may be a cleaner way of using 1.44s on 520 /1040 STes

Question : Does anyone have a 520 STe with serial number starting with X that also may have Ajax chips installed?

Chance227

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Thanks again Simbo

Postby chance227 » Fri Mar 02, 2007 12:06 am

Simbo
Thanks for the reply and much needed info

I will chase that up this weekend and see how I go

( background ) I suspected that Atari were using the Later 520/1040 STes for testing of the Chipsets prior to the Falcon being released, but still looking for evidence that was the case.

I will post some images of my unit/s this weekend and show what I beleive that 1.44 and Tos 2.06 with full support was possible in later 520/1040 STes back in the early ninties 90-92

Regards Chance227

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Postby MiggyMog » Fri Mar 02, 2007 10:08 pm

The chip has the following details:-

atari
c302096-001a
tc24sc060ap-001
japan 9135ea1


One of my STE's has a serial no with X2 before it....
('< o o o o |''| STM,2xSTFM,2xSTE+HD,C-Lab Falcon MK2+HD,Satandisk,Ultrasatandisk,Ethernat.

simbo

Postby simbo » Sat Mar 03, 2007 12:44 am

the c code is atari specific

the tc24sc060ap-001

is the real number
most controllers even wibond types used in most st's

just need the clock to be doubledand the signals changed at the cable
header
to comply with 1.44mb floppys {buy a satan disk there is no more chance to }

simbo

Postby simbo » Sat Mar 03, 2007 12:44 am

the c code is atari specific

the tc24sc060ap-001

is the real number
most controllers even winbond types used in most st's

just need the clock to be doubledand the signals changed at the cable
header
to comply with 1.44mb floppys {buy a satan disk there is no more chance to }

simbo

Postby simbo » Sat Mar 03, 2007 12:45 am

the c code is atari specific

the tc24sc060ap-001

is the real number
most controllers even winbond types used in most st's

just need the clock to be doubled and the signals changed at the cable
header
to comply with 1.44mb floppys {buy a satan disk there is no more chance to }


http://www.atari-forum.com/viewtopic.ph ... 3da3d3c711

looking at previous posts with google using find similar
i note knowone mentions it as different in anyway
i recon you should houk it out
and replace it with the later WD type chip - AA version if i remember
you need to study
but that conroller will do
but its 001 -AA is the same as the WD chip exactly the same
it will work with double speed {16mhz hd } clock
but the WD -AA version is better its up to you
either way youll need o change the clock
and also the cable
and also you need tos 2.06 or higher in ste to support hd floppy

....

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Postby chance227 » Sat Mar 03, 2007 2:32 am

Hi there Simbo and Miggmog

Yes thats a Ajax chip OK
Here are my snapshots of the STe

You will notice mine is setup for Tos 2.06 with access to the format
drive option from the desktop and my Ajax chip is surface mounted
from the factory. On my second machine (not shown) it is socketed
on the board with a Ajax chip inserted on top, again with the Tos 2.06
mods.
I have fitted a chinnon 1.44 changed the jumpers to D0 from D1
twisted the floppy cable around and can read and write 720k disks
with no probs.
Simbo if I just change the crystal from 8mhz to 16 mhz could you see anything else that would need doing? I am finding that the square 4 pin 16 mhz crystals are as rare as hens teeth here and am worried I am not going to get them at all!!
If I go the XOR doubler option what parts and soldering would I need to do? which would be the cleaner and less soldering option, as I am not too
skilled in that area?

Chance227
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simbo

Postby simbo » Sat Mar 03, 2007 2:58 am

DONT change the crystal
you need to double the clock to just that ic
as this 8mhz clock is used in other stages
so changing the crystal will change there running frequency also
so you take 8mhz and make it 16 mhz using an xor gate 74hct86
two gates = X2 8mhz then its 16mhz supplied
look at vezz site
the mod is there for 1.44mhz using a similar chip to 74hct86
http://forum.atari-home.de/index.php?topic=1415.msg5256
look at this post for referance
its the same chip so apply the 1.44mb standard 1 chip mod on vezz site
http://atari4ever.free.fr/hardware/drives.html
the ajax ic is the same as the advanced WD chip die model
and is already setup for hd just a clock change to it
you can run this chip at higher data rates
clock *4 so 32 mhz
to gain extended floppy 2.88mb
but just doubled to 16 is fine

i see your 1.44 reads and writes
so modify the clock to the controller is all thats needed

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Re: Thanks again Simbo

Postby ijor » Sat Mar 03, 2007 2:11 pm

chance227 wrote:I will post some images of my unit/s this weekend and show what I beleive that 1.44 and Tos 2.06 with full support was possible in later 520/1040 STes back in the early ninties 90-92


We talked about this several times already.

Any ST with any TOS can use HD drives and floppies.

The Ajax chip is recommended but in many (most?) cases it is not absolutely necessary. The Ajax chip is just the same as the plain WD FDC factory guaranteed to work at 16Mhz. Many (again, most?) WD parts can be overclocked anyway.

Any TOS can use HD floppies. Earlier TOS versions don't have the HD formatting option, but you still can perform HD formatting using a third party utility.

The original HD upgrade has a clock switch. Do you realize that by just doubling the clock permanently then you are loosing DD compatibility?

ppera

Postby ppera » Sat Mar 03, 2007 2:43 pm

Saying 'any' ST is little simplified.

In praxis about 50% WDC chips will work reliable on 16MHz. It is not bad, but is far from any. And aging may play role: in my STFM it worked flawless before 20 years, but now it has problems with HD floppies often.

Steprate issue: you need some solution for setting steprate to 6ms when work with HD floppies.
I solved it by bootsector on floppies but it is not general solution. There was even no Xbios function for it before TOS 2.06.

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Postby ijor » Sat Mar 03, 2007 2:56 pm

ppera wrote:Saying 'any' ST is little simplified.
In praxis about 50% WDC chips...


Please read again my post. I didn't say every ST is factory ready for HD.

Steprate issue: ...There was even no Xbios function for it before TOS 2.06.


There is a documented way to set the step rate in any TOS.

ppera

Postby ppera » Sat Mar 03, 2007 3:56 pm

ijor:

Let just say that your formulation is not enough clear. We can like that say then: any ST can run at 16MHz (just need to replace and add something...).

You are welcome to post link or quote how to simply set steprate in any TOS.
I know only that system variable is not on same addresses.

simbo

Postby simbo » Sat Mar 03, 2007 5:18 pm

sorry your very wrong
you can overclock older chips and they will work
but they will exibit packet loss
to the untrained eye you wont notice as the drive just rereads to gain crc
hence the reason for hd and ed complient chips as later die models
the ajax chip is just a custom die
basicaly made by atari becouse the western digital older die had problems
and its also the reason some floppy drives just refuse to read properly
till you replace it with the later WD die model
this was an imporved ajax chip
.....
so its swings and roundabouts
if it works you win a watch
if it is tempremental replace the chip

i dont see anyreason to start to flap

the topic i pointed out in german sayes this already

http://www.atari-forum.com/wiki/index.php/WD1772

read this wiki entry youll see it confirms the synopsis

ppera

Postby ppera » Sat Mar 03, 2007 7:14 pm

As usual, I posted according to my experiences. I made few HD floppy mods in ST machines.
Do others talk from practice or just talk theory...
Instead tons of posts maybe little more experimenting would be good...

That talk about rereading is nonsense - it reads not, gives errors and that's it.

Buying Ajax chip now, when floppy is in distinct don't looks me as good investment.
Even Simbo proposed that drop out floppy and attach satan and network...

Of course it is worth to try will HD floppy work, but it is not for people without some electronic knowledge.

I will post here simple schematic how to do it - automatic 8/16 MHz switch using sensor from floppy drive. Taking 16 MHz from shifter chip, and with multiplexer choose which freq...

simbo

Postby simbo » Sat Mar 03, 2007 7:30 pm

ppera wrote:That talk about rereading is nonsense - it reads not, gives errors and that's it.





any floppy disk will attempt to reread by a preset number of tries then issue an error

if you have a die made for 8mhz DD disks

then apply 16mhz clocks
youll get gate glitch becouse the chip is NOT designed to do this extra speed
gate glitch can and will cause packet loss
so the disk will then attempt to reread the sector
so i personaly have fitted many hundreds of HD mods and quite a few ED mods way back 10 years ago


and your right
throw the floppy in the bin :P

and use satandisk :?:
once its had mods to allow pc read write access via usb added
becouse i personaly wont buy it till it has :!:

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Postby ijor » Sat Mar 03, 2007 8:44 pm

ppera wrote:You are welcome to post link or quote how to simply set steprate in any TOS.I know only that system variable is not on same addresses.


I said "documented". Just in case it is not clear, that means officially documented by Atari. There aren't too many official TOS documents. So do your homework and you'll find it.

ppera

Postby ppera » Sun Mar 04, 2007 8:46 am

[quote="ijor]
I said "documented". Just in case it is not clear, that means officially documented by Atari. There aren't too many official TOS documents. So do your homework and you'll find it.[/quote]

I don't think that this forum is intended for such answers.

People made mods, interfaces, software before WWW era, before wide available official TOS documents.
Did they in those times replied like this: 'Ah, it is peace of cake. Just buy Atari Profubuch - there are all details....' ?

Here is project for HD floppy mod, very similar to what I made:

http://solair.eunet.yu/~vdjole/atari.htm

Automatic switch + ...

Here is the homework:
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simbo

Postby simbo » Sun Mar 04, 2007 10:39 am

Schematics, PCB layout and instructions for building and installing a simple one-chip HD-floppy module into ST and MegaST range of computers. An interesting feature of this particular design is that it switches the floppy-controller chip into 16 MHz mode only when a HD-floppy is inserted into drive, thus preventing needless overheating of the overclocked WD1772 chip. Instructions for physical installation of the device in the computer are included.

the bit i marked in red is helarious
:P
you added a facet to reduce any overheat this wont happen
if you use an 0202 type as its designed to run upto 32mhz

? just how many floppys do people actualy use these days
i recond around about zero or maybe 1 or 2

the very same mod appeared in several magazines around 1985
the trick is you only need to double the clock using one gate
and change the chip for the better die 02- 02
and thats it if i remember once people had 1.44
then they threw there 720k disks in the bin

above all this type of general modification to that ic
isnt recomended for the reasons i noted and ijor confirms
always better to change the ic to a later model
as heat is only 1% of the problems youll then have
as the older die will throw up problems with dataloss if you overclock it

i see you cover yourself on that point
as in the img file i see that you
note a 02-02 but say stupid things about it
and an uneducated guess or two

reading the text from your project i arrived at this passage


" * Existence of a WD-1772-02-02 floppy-controller chip in the computer; the
02-02 suffix means that the chip is intended for wider temperature range,
and so it can work reliably when overclocked. It is quite probable that
chips without the 02-02 suffix will not work, On the other hand they may-
because the overheating is reduced with this circuit.
"

man its official

i think you need to go to school

go to the wiki read the datasheet on that ic

i first read it in 1885


and you need to go to school becouse you have made the very same error
every single amature electronics 'guess and hope ' guy does
you forget to add the load resistors 220R or 330R
in the clock pin input path
thus both the western digital floppy controller
and also the ic you added will have to sink current on its clock pin
and it will get hot or hotter than it should
i would say to you one simple thing
go and make the design properly then bleet about it



.....

ppera

Postby ppera » Sun Mar 04, 2007 2:13 pm

So, we are again where been before 1-2 months...
Insulting, not reading carefully others post. Only new thing is deleting of some posts without warnings...

Just to mention that I'm not Djordje Vukovic, author of that project/article.

Instead insultings and playing smarthead Simbo could notice one very interesting idea in project - how to solve step rate problem with little additional hardware...
Not like Atari did in TOS 2.06 - fixed steprate to 6 ms for all floppies. Crap.

Can we talk here as civilized people some technical problems without preaching, theoretising and other unnecessary things - especially those with big blue font ?


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