ATR8000 Reversing Project

[tschak909]

Anything ever come of this?

[Jeffrey Worley]

On 12/3/2014 at 8:54 PM, ricortes said:

For some reason I thought the 8500 needed a co-power88 board to work. Can anyone confirm this? I also thought the 8500 was scsi so a bit hard to find drives nowadays. hehe a bit hard to find floppies too!

No.  For sure not.  I had an 8500 and it worked just fine with no other boards.  It is a board about the size of an Adaptec ACB4000a, would bolt nicely to the top of a 5 1/4" floppy mechanism.  It has its own CP/M version as it has a hardware UART.  That is the only real difference between the 8500 and the 8000, the UART.  The 8500 does not have rectifier circuits on the board, needs a number of dc inputs to work, including some negative inputs.  I don't know if the Copower was ever installed on one, or the hard disk interface.  There were only a handful made.  Mine was serial number 5, came with full schematics, disks, the whole shooting match.  I bought it from B&C computervisions in 1998 or so.  Curt Vendel has it in his collection.

 

Best,

 

Jeff

[Jeffrey Worley]

I just accidentally discovered that the ATR8000 CAN do enhanced density.  It can't FORMAT enhanced, but if you stick a disk already formatted in EH in the drive, the controller recognizes that it is MFM 128byte sectors, which is wild.  It doesn't know that there are 26 sectors per track, so you plug that into the control block using PBSET or some other utility and it works.

 

Best,

 

JEff

[+Larry]

I'm curious about the possibility of a modern version of this, although I'm not sure that it would offer much in terms of features for users.  I've had a couple of these -- man they are huge!  Huge pcb and a box to match.  Putting this into an FPGA, it could be even smaller than the mini Eclaire XL.

 

But again, what is the purpose/benefits?  When these came out, a big selling point was that you could attach lower cost slave drives instead of purchasing $450+ 810s or Percoms.  But today, it is difficult to even find good PC type drives (other than the mini 3.5" type).  And with all the cartridge and other substitutes (like APE, RespeQt), attaching floppy drives doesn't seem like a big deal.  Run CP/M?  Really?  Connect to a retro bulletin board?  Maybe this just belongs to collectors as-is.

 

-Larry

[Jeffrey Worley]

1 hour ago, Larry said:

I'm curious about the possibility of a modern version of this, although I'm not sure that it would offer much in terms of features for users.  I've had a couple of these -- man they are huge!  Huge pcb and a box to match.  Putting this into an FPGA, it could be even smaller than the mini Eclaire XL.

 

But again, what is the purpose/benefits?  When these came out, a big selling point was that you could attach lower cost slave drives instead of purchasing $450+ 810s or Percoms.  But today, it is difficult to even find good PC type drives (other than the mini 3.5" type).  And with all the cartridge and other substitutes (like APE, RespeQt), attaching floppy drives doesn't seem like a big deal.  Run CP/M?  Really?  Connect to a retro bulletin board?  Maybe this just belongs to collectors as-is.

 

-Larry

It doesn't give much, not really.  The cool factor is being able to run CP/M software and one can do that with other devices that use an FPGA in support of a genuine z80 and ctc.   There are a couple of incarnations already in productions:  Here's a thread on one:  https://www.retrobrewcomputers.org/forum/index.php?t=msg&th=463&goto=7426&

 

As a CP/M machine the ATR8000 is very flexible.  I like it quite a lot, versus others I've used, the Osborne, Kaypro II/IV/10.  It has great flexibility in the drives it will control, and will run the Atari as a terminal, or a standard RS232 terminal, or, I suspect, a standard RS232 terminal using an Rverter on the ATR's SIO port.  That last would save the RS232 port on the ATR for a modem or other needed connection.

 

Best,

 

Jeff

[tschak909]

2 hours ago, Jeffrey Worley said:

It doesn't give much, not really.  The cool factor is being able to run CP/M software and one can do that with other devices that use an FPGA in support of a genuine z80 and ctc.   There are a couple of incarnations already in productions:  Here's a thread on one:  https://www.retrobrewcomputers.org/forum/index.php?t=msg&th=463&goto=7426&

 

As a CP/M machine the ATR8000 is very flexible.  I like it quite a lot, versus others I've used, the Osborne, Kaypro II/IV/10.  It has great flexibility in the drives it will control, and will run the Atari as a terminal, or a standard RS232 terminal, or, I suspect, a standard RS232 terminal using an Rverter on the ATR's SIO port.  That last would save the RS232 port on the ATR for a modem or other needed connection.

 

Best,

 

Jeff

Achtkually*snort*

 

The RS232 terminal jumper on the ATR8000 affects the SIO port. If you set to serial terminal mode, then the SIO port emits RS232 voltages, and you needed a cable (that SWP sold) that broke out to a standard DB25 connector.

 

-Thom

[Jeffrey Worley]

7 hours ago, tschak909 said:

Achtkually*snort*

 

The RS232 terminal jumper on the ATR8000 affects the SIO port. If you set to serial terminal mode, then the SIO port emits RS232 voltages, and you needed a cable (that SWP sold) that broke out to a standard DB25 connector.

 

-Thom

Hey thanks!  I wondered forever how that worked.  I assumed it was an Rverter-style cable from the SIO or a terminal on the RS232 port but never knew which.  NICE!  I think I'm going to build this cable.

 

Best,

 

Jeff

[somejoe]

Resurrecting this years-old thread.

Did the project go forward? I'd like a copy of the newly drawn schematics.

And, does anyone have a copy of the copower88 / ATR8500 schematics?

TYVM,

 

[somejoe]

On 11/28/2014 at 5:34 PM, Jim Patchell said:

I decided it might be fun to reverse the ATR8000. The schematic really sucks, at least, by todays standards. My first step is to redraw the schematic. The copy I have is a Rev C. Were there any other revs?

 

The second question is, does any body know the bit pattern in U46. This part is a 32x8 prom. But only 16x4 of it is being used. It would be nice if somebody has already done this, but I will get it myself if I have to.

 

Just for fun, here is the image of the Data Separator for the ATR8000.

 

http://www.noniandjim.com/Jim/ATR8000/DataSeparator.png

Would you mind sharing the rest of the newly redrawn schematic if you have it?

[+MrFish]

21 hours ago, somejoe said:

does anyone have a copy of the copower88 / ATR8500 schematics?

SWP: Co-Power

 

[+MrFish]

4 hours ago, somejoe said:

Would you mind sharing the rest of the newly redrawn schematic if you have it?

If you hover over @Jim Patchell's name, you'll see he hasn't been on these forums since Feb. 2021. He might receive a notification of your message to him (the site will send notifications to an email address if enabled in the user's settings); but it's just as likely, or more so, that you won't hear anything.