While working on a couple Atari 1050 floppy drives found a weird upgrade board... What is it?

[E474]

Hi @kheller2,

 

   Thanks very much for the link, that's very detailed info, and includes everything I was after!

[+Nezgar]

On 2/2/2022 at 12:25 PM, Verault said:

Since this is the only readable part of the eprom in ascii I take it still not enough info?

This is the duplicator 2.31 ROM - there is a later 3.0 ROM on this site:

http://realdos.8bit.ca/1050 Duplicator.html

 

The file "DTIREV5.EPM" is v3.00 with Atari binary load headers... I exported that segment for the raw 8KB BIN, you can burn this to your EPROM to "upgrade" your drive. I've attached a "clean" .BIN file here. I think I recall something about a v3.1 as well -- I'll have to search around.

 

There's enough info on that site to easily build a replica of this board, which E474 and I are now looking into. Nice thing about this upgrade is the creator has actually declared it public domain, source available and everything.

1050 duplicator 3.0 22C4FAFC.bin

[Verault]

Thanks for the info on the the upgrade ROM River Patroller!

[BillC]

12 hours ago, Verault said:

River Patroller!

FYI "River Patroller" is a rank, more posts made gives a higher rink, not a user ID.

[Verault]

thats why I shouldnt read forums on my phone.. I cant see the screen.

[manterola]

On 3/17/2022 at 7:55 PM, E474 said:

Just curious how simple it would be to reproduce the board, given the firmware is available?

It was not hard. But now I need to actually assemble one PCB, burn the firmware, etc. and test to see whether this thing works.

Edited April 14, 2022 by manterola

[E474]

Hi @manterola,

 

  That looks very nice!

 

   I built the firmware last week - the ATASCII sources have some extra characters at the end of DD15M1.ASM, which need to be stripped out before it will compile (fixed file attached). Also, you need the Atari Macro Assembler (attached), I used the options in the screen shot to get it to assemble the sources correctly (I put the sources on a 2nd MyDos ATR, which I created as a 16MB image, so I had enough space for listings, etc.) - this was with the atari800 emulator on Linux.

 

   Also, you might want to mark out space on the PCB for the trimpot resistor to slow the drive down to 270/272 RPM (SIO command "j"). I don't know if it only needs a trimpot resistor, or something else too - I haven't got round to looking at the 1050 schematics for the standard trimpot resistor circuit (for drive speed), so don't know if it's standalone or not.

 

    Hope this helps!

 

DD15M1.ASM AMAC_MyDOS.atr

[+Nezgar]

4 hours ago, manterola said:

It was not hard. But now I need to actually assemble one PCB, burn the firmware, etc. and test to see whether this thing works.

Great work @manterola! Big surprise to me as I have been working with a friend to make a new replica Duplicator 1050 PCB design as well -- I'm currently waiting on the prototypes to arrive. We reworked the layout to shrink the footprint as much possible while keeping the original IC's, and added a ROM bank select to hopefully allow for a switch between 2 revs of Duplicator firmware, or the original 1050 OS (if programmed in half of a half of a 27128). I have been in communication with @E474 who inspired me with the idea to start this in the first place (it was a big jump in complexity from my 6810 doubler PCB's!), and have been brainstorming with him many potential future enhancements (like maybe integrated happy/cheerup support) and of course the potential of improving the firmware starting with being able to compile from original source, but figured I better make sure Rev 1 works first.

 

Anyhow, I was going to wait until I confirmed if it works before posting anything, but without further adieu here's a sneak preview: ?

[+kheller2]

 

We should also seriously consider fixing the format "feature" for the first three sectors.  Then it will be a very nice fast drive with track buffering.

[+Nezgar]

8 minutes ago, kheller2 said:

 

We should also seriously consider fixing the format "feature" for the first three sectors.  Then it will be a very nice fast drive with track buffering.

Yes.... that is also my prime desired bug to fix.

[E474]

It's on my to do list, which is why I built the firmware last week, but if anyone wants to jump in and figure out a fix first I won't complain!

 

[manterola]

@Nezgar , that PCB looks great. I just started from the original one and re did it with the same layout, thinking more about having the correct schematic first. I thought, if this work, i will be able to move the components around and optimize. You already did it! I hope there is no copyright problems ahead, and this 1050 mod + your additions and improvements could be some kind of Open source/hardware project.

 

[+kheller2]

On 3/20/2022 at 12:58 AM, Nezgar said:

This is the duplicator 2.31 ROM - there is a later 3.0 ROM on this site:

http://realdos.8bit.ca/1050 Duplicator.html

 

The file "DTIREV5.EPM" is v3.00 with Atari binary load headers... I exported that segment for the raw 8KB BIN, you can burn this to your EPROM to "upgrade" your drive. I've attached a "clean" .BIN file here. I think I recall something about a v3.1 as well -- I'll have to search around.

 

There's enough info on that site to easily build a replica of this board, which E474 and I are now looking into. Nice thing about this upgrade is the creator has actually declared it public domain, source available and everything.

1050 duplicator 3.0 22C4FAFC.bin 8 kB · 10 downloads

I thought I posted my v3 ROM in one of this threads.    But from the source comments we have this:

 

; 2793/2797 VERSION
; REVISION 1.10
; REVISION 2.02
; REVISION 2.20
; REVISION 2.30
; REVISION 2.31
; REVISION 2.40
; REVISION 3.00 FIXED TRACK 0 CAL PROB
; REVISION 3.10 MADE UNBUFFERD DEFAULT
; LAST UPDATED FEB 21, 1987

 

I again have no idea why one would use 3.1, turning off buffering was as easy as booting a three sector disable disk and buffering is what made this one of my favorite upgrades. 
 

 

[+Nezgar]

15 hours ago, kheller2 said:

I again have no idea why one would use 3.1, turning off buffering was as easy as booting a three sector disable disk and buffering is what made this one of my favorite upgrades. 

I agree, but I imagine all it took was a customer to complain about data loss when removing a disk prematurely if this applied to buffered writes... maybe 3.1 was only offered to "those" customers. ?

[manterola]

Mine did not work properly. It is a very erratic behavior, sometimes it start to boot the disk and it just stops in the middle, other times it does not even respond to any SIO commands at all. I will try connecting the 27128 additional pin to ground to see if it does a difference, and I will try other firmwares as well (this was a very short test just after having my PCB with the sockets soldered, and using a 27128 instead of 2764 since I could not find any empty)

[manterola]

Yep, pin26 to ground made it happen! 

 

[manterola]

I am not very happy with this upgrade so far. It looks like writing with bufferiung is making some copiers to fail during the writing phase. I tried Mycopier, and USCopier. I will need to keep reading the manual...

[E474]

Hi @manterola,

 

    Glad to hear the upgrade is up and running, but what exactly is the problem with the disk copiers? Is data not written (I don't usually copy with write with verify set, so would only find out later if the copy was bad), or is it returning write errors, or something else (timeouts, etc)?

 

   Also, have you looked at the slow down mod - it's written up in the Installation manual on Internet Archive, but I think it's only a standard trimpot resistor like  the normal adjust rpm trimpot.

 

   Back to being a bit swamped at the moment, so no progress on building/investigating the firmware.

[manterola]

I replaced the ls00 and also re inserted the mod (i need to replace the pin headers since they are a bit to short) I don't know what made the difference but it's working great now. 

It's is super fast doing copies with standard copiers.

I'm interested in the pot modification, but beside the manual mention and the program to calibrate the speed, i haven't found any information about it.

[E474]

Sorry for the following eye-watering paste from my notes/email:

 

The source code reveals DD15M2.ASM, lines 1109 onward:

CSEL21	CMP	#'j'	;rpm change?
	BNE	CSEL22
;
	JSR	DELAY
	JSR	ACK
	LDA	CMDFRM+2	;LOAD AUX1
;
;AUX1=0 IS NORMAL SPEED
;AUX1=1 IS SLOW SPEED
;
	BNE	:CS211
;
;NORMAL SPEED
;
	LDA	DRA
	ORA	#$04	;SPEED CHANGE BIT
	STA	DRA
	JMP	:CS212
;
:CS211	LDA	DRA	;SLOW SPEED
	AND	#$FB
	STA	DRA

With DRA defined as:

DD15M0.ASM:DRA  =       $0280   ;6532 DATA REGISTER

and the BitWriter Manual.pdf, page 2, lists the pot as 20k ohms, which I assume is correct.

 

I don't actually have a Duplicator board to test anything on, and am back to being very busy with stuff that wants to bite me.

 

Good news that your board is now working correctly!

 

 

[manterola]

I can send you one, meanwhile Nezgar is waiting for the parts for the new designed PCB. No strings attached...

BTW, I guess I should start a new thread regarding 1050 Duplicator

Edited April 23, 2022 by manterola

[E474]

@manterola, PM sent!

[SviRu]

On 2/13/2022 at 10:06 PM, Verault said:

Well the drive came out real nice. The metal badge still had the plastic sticker on it to peel off and after retrobright it looks brand new. And it came with its own vinyl dust cover.  Im pretty happy with it all.

 

 

Metal badge didn't get destroyed during retrobright process?