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Authentic Reproduction ATR8000 Interest?


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Update on the Mini ATR-8000:

 

I finally got my AM27S19 programmer to work. I have now programmed 3 PROMs. (For those of you wondering why this is necessary it's because of the access time. Old EPROMs are too slow.

New parts like the SST39SF010A-55-4I-WHE might be fast enough but I will test that later).

AM27S19programmer.thumb.jpg.e9a6fd13573e6a396320f0ef41fd20df.jpg

Only blew up 5 ICs along the way - two AM27S19s, two 74LS138, one 74LS164, and one PIC18F2550-ISP (those are $7 USD now!! so I added a Blue Pill option).

Here is the updated PCB 3D model. Time to order Rev. 2:

image.png.05705e97bd20301a261347f6b5e2207f.png

 

And now for the main event. In this video I have the Mini ATR-8000 connected to my Linux Machine using a real USB to RS-232 cable and a special ATR-8000 to RS-2323 cable (standalone mode, jumpers J7 and J10 in TERM position).

The click at the beginning is the power turn on for the open frame switching power supply I'm using. Then you can hear the Mini ATR-8000 seek and spin the drive. Next I press enter to bring up the ATRMON prompt. Then I enter the command B and press enter. The drive spins and I get ERR 10. This disk is an unformatted disk from my stash. I think if I had a disk with CP/M on it I could boot CP/M:

 

 

I tried connecting the Mini ATR-8000 to my Atari 400 last night (after moving the jumpers at J7 and J10) but it did not work. I heard weird SIO noises and the other attached device wouldn't work.

I think I need more pullup (lower value resistor) but I will confirm with my scope/volt meter. Nothing was damaged - the Atari 400 still works fine with the FujiNET attached.

 

Getting closer!

 

  • Like 2
5 hours ago, _The Doctor__ said:

SIO noises could have been the ATR trying to boot disk 1 in the drive, did the drive spin?

I didn't even connect the drive. My understanding is that the ATR-8000 will act as a print buffer when 64k RAM is installed, so I just used the LPRINT command in BASIC. These were not SIO sounds I have ever heard before.

 

Trying again tonight.

5 hours ago, StartedWith400 said:

I tried connecting the Mini ATR-8000 to my Atari 400 last night (after moving the jumpers at J7 and J10) but it did not work. I heard weird SIO noises and the other attached device wouldn't work.

I think I need more pullup (lower value resistor) but I will confirm with my scope/volt meter. Nothing was damaged - the Atari 400 still works fine with the FujiNET attached.

Did you try it without any devices connected? LPRINT to a buffer should be staccato SIO packets.

The SIO devices all need to be compliant, it sounds like it's not getting and giving up the SIO buss like it should.

24 minutes ago, StartedWith400 said:

I didn't even connect the drive. My understanding is that the ATR-8000 will act as a print buffer when 64k RAM is installed, so I just used the LPRINT command in BASIC. These were not SIO sounds I have ever heard before.

 

Trying again tonight.

I think I found the problem - errant strand shorting pin 3 to GND:

image.png.9008db17eedcea97374c06b3a49580d7.png

Posted (edited)

The SIO problem is fixed. Now I can use LPRINT from BASIC and I hear the short burst of data that I would expect and no error is reported.

 

I connected a known good 360K 5.25" FDD and set it to DS0, termination resistors installed. I inserted an unformatted disk. When I power on the Atari the drive spins and loads the heads (this drive has an electro-magnet that pulls the head to the disk surface). I hear some SIO beeps followed by long pauses, then BOOT ERROR. This is somewhat expected as the disk in not formatted.

 

I then swapped the SIO cable to a known good drive (set to ID 1) and booted MyDOS 4.5. Then I swapped the SIO cable back to the Mini ATR-8000 and tried a format. Oddly there was no disk activity and only SIO sounds line there is nothing attached followed by Error 138.

If I try a directory listing (enter '1' at the prompt), the drive spins and I hear some SIO beeps followed by long pauses. Tried this multiple times and with Atari DOS 2.0S, and then Atari DOS 2.5.

 

I used a real Atari 810 to format the disk and copy the DOS files (2.5). When I try to boot I hear some SIO beeps followed by long pauses, then BOOT ERROR. Swapping SIO to get into DOS then swapping back, still when I try a directory listing (enter '1' at the prompt), the drive spins and I hear some SIO beeps followed by long pauses.

 

Shouldn't I be able to format a disk? I read in the SWP documentation that the printer buffer prevents the ability to format a disk, so I installed J11 to disable the printer (not sure if that disables the print buffer too, but I would assume so). Still the same results.

 

I tried another FDC chip (Fujitsu MB8877A) and still the same results. Finally I tried a known good 5.25" 1.2MB drive (terminators in, DS0, only drive attached to the Mini ATR-8000). Still the same results.

 

Next I'll try a different floppy drive cable. After that, out comes the Oscilloscope.

 

Ugh - it's fighting me every step of the way.

 

In this video I try to format 2 times - first showing the screen, second showing the floppy drive.

Edited by StartedWith400

Great news - It works !!!!

 

 

 

Probably the first new ATR-8000 in almost 40 years. I am so relieved to finally se it doing what it's supposed to do.

 

I think my real 810 is out of alignment and caused me a bit of confusion.

 

I also don't understand why formatting didn't work the first time I tried it, but I leaned a few things that may have been the cause:

- Even though I moved the drive select jumper on the floppy drive (DS0 - DS3 for this drive), the drive needs a power cycle or reset to detect the change.

- After the drive select is changed and the drive is rebooted, the Mini ATR-8000 needs to be reset to identify the change.

  • Like 4
  • Thanks 1
Posted (edited)

Fantastic break through!  This has my full attention.  Really cool project.  Try using MYDOS to format a 5.25" 1.2MB high density disk.  MYDOS can format the 5.25" HD as a Shugart 8" floppy drive.

high density = YES

double sided = YES

sectors per track = 77

 

It will format to a total of around 1.0MB in MYDOS.  The ATR-8000 thinks it's an 8" floppy.

 

 

Edited by ACML

Now that I know it works, let me know interest in acquiring one. Here is one member who is interested:

scitari wrote: Please! I would love to see this come to fruition and would definitely buy one :)

 

The next revision of the board I plan to make will be Rev. C (huh - just like SWP). I have incorporated the combination SIO/DB-15 connector footprint (thank you mytek for the model) and I expect to use a Molex power connector the same as a floppy drive. I can generate the -12V and -5V using a CUI 7812 in negative output mode. Here is the 3D mockup:

image.thumb.png.b25981c4defbab7108b11a918ff782e1.png

 

Differences from the real ATR-8000:

- The reset switch is not on the back - instead is is a pin header in the lower left of this image (S1). That way the switch choice and location is independent of the PCB layout.

- I added solder shorting options on the bottom side so that J1 through J10 can be selectively eliminated.

- J13 was added to allow optional ROM image selection on larger ROMs - still only half of a 2764 but each half could have different code. Note that J9 is useless - since revision 3.02 requires 4k, it will always be in position 2-3.

- Footprint for a CUI 7812 on the back side and option jumper to use it. This would allow the entire board to be powered by +12 and +5 through a floppy style power connector. Otherwise -12V can be fed in through one of the ground positions.

- Ideas I have: Add USB to serial IC and USB port for TERM mode. Pin header for USB to UART (5v) that could be used instead of the RS-232 port - probably not that useful though.

 

kenp wrote: Thinking about this ... I cannot help but think that an ATR8000 might make a heck of a reverse sleeper in a [vintage] ATX case.

I can now change the layout to fit this shape if there is enough interest. The biggest concern is availability of FD1793 or FD1797 ICs. I could also invert the Data Buss connections and use the less common FD1791 or FD1795.

 

Using a PAL/GAL to package the logic would probably reduce the part count significantly. I also think that the data separator could be replaced with the FDC9216 8 pin IC or the whole section with the FD2797 (although I think there are software issues that would impact CP/M functionality).

 

At this time I have enough parts to make 15 Mini ATR-8000s. That would include two SIO to DB-15 cables and the parts on the PCBA. It would not include a floppy cable or floppy drive. It may include a power supply.

I don't have a case design and I am considering options. It might be fun to have a sheet metal case made to look like the original. Not sure on case cost but I'm thinking the whole thing could be less than $200 USD. It's a lot of soldering.

 

Thoughts?

 

 

 

 

  • Like 2
21 minutes ago, ACML said:

Fantastic break through!  This has my full attention.  Really cool project.  Try using MYDOS to format a 5.25" 1.2MB high density disk.  MYDOS can format the 5.25" HD as a Shugart 8" floppy drive.

high density = YES

double sided = YES

sectors per track = 77

 

It will format to a total of around 1.0MB in MYDOS.  The ATR-8000 thinks it's an 8" floppy.

 

 

I'll go try it now. I also have four 8" floppy drives I can test with. I've got a lot of stuff.

Posted (edited)
2 hours ago, StartedWith400 said:

I'll go try it now. I also have four 8" floppy drives I can test with. I've got a lot of stuff.

Sorry, getting old.  It's 77 tracks, double sided, double density.  When you select 77 tracks, I think it auto populates 26 sectors per track.

 

 

Edited by ACML
8 hours ago, ACML said:

Try using MYDOS to format a 5.25" 1.2MB high density disk.  MYDOS can format the 5.25" HD as a Shugart 8" floppy drive.

high density = YES

double sided = YES

tracks = 77

 

It will format to a total of around 1.0MB in MYDOS.  The ATR-8000 thinks it's an 8" floppy.

 

 

I tried this with two known good 1.2MB floppy disk drives I have and it did not work. I also tried 80 tracks and 40 tracks without success.

MyDOS 4.53/4 asks (O command):

Drive number or RETURN: 2 (I have DS1 set on the drive)

Remove drive? N

Is drive configurable? Y

High capacity drive? N  (I think this is for SASI HDDs)

Is drive double sided? Y

Tracks/side? 77 (only allowed answers here are 35, 40, 77, or 80)

Step rate? 0 (should be 6ms/track)

 

Whats strange is that if I power cycle/reset the Mini ATR-8000 with just the 1.2MB FDD attached, all attempts to talk to it fail with error 138 (timeout).

My understanding is that the ATR-8000 identifies the drive at start up - I don't know why it works with the 360KB drive and not the 1.2MB drive.

 

I tried "tricking" it by powering up with the 360K FDD and then swapping to the 1.2MB. This at least seemed to allow the format to proceed, but it was VERY slow and timed out at track 70.

I really don't understand what is going wrong here. I'm going to look at the selected SEP CLK/FDC1797 CLK selection to see if it is changing (although I think MyDOS sets this).

 

I would be very interested in one unit also. I have an ATR and it may work, but all the drives are not working as I think they should. I think the hard drives I had and was high where 5MEG..HAHAHA. My 5.25 floppy are around here also somewhere and the software for the BBS I ran in the 80's is, but I need to find it.. I had an 8" also, but it was not very reliable.

Peter

Posted (edited)

 

 

More good news - I was able to boot CP/M on the Mini ATR-8000:

 

 

A big thank you to sup8pdct (from: https://atariage.com/forums/topic/220185-atr-8000-and-other-cpm-system-disks-here/page/6/?tab=comments#comment-2997486) for putting together the files and making an EXE to prep the formatted disk.

I am using a real Atari 800 (with the Atari 48k RAM upgrade, so it's essentially an Atari 800 inside) and the program CPMBOOT.EXE did not complete correctly. I suspect I need more RAM. I'll dig out one of my XL or XE models to try again. But, as you can see in the video, it does boot and can run STAT.COM.

 

FINALLY !!!

 

Edited by StartedWith400
  • Like 2

CPMBOOT.EXE is a program created by user sup8pdct that makes some edits to the disk image copied from an ATR called CPMFILES.ATR (for all the details, see the link I provided in the post above). Essentially the issue is that CP/M needs the first sector (or maybe first few sectors) single density and the rest can be double density. I don't think the ATR image could mimic that so the CPMBOOT.EXE program is run after you create a real disk image of the ATR image.

  • Like 1
Posted (edited)
16 minutes ago, kheller2 said:

There is an Atari program, AutoTerm? that is used to connect to the ATR as a terminal.

Yes, and I was trying the one in the file ATR8000_boot.zip (again in the post referred to above), but it seems to have some other automatic commands or something the interferes with the basic function of the terminal (I kept seeing an unexpected prompt "A0>"). This may again be due to using a 48k computer. So, I used the ATR/TERM jumpers and my "ATR8000 Terminal Cable". It's similar to using a standalone terminal and I get true 80 columns (or more).

image.thumb.png.5290e79f7341946f3ddc238ca891f00c.png

Edited by StartedWith400
Posted (edited)

I found the detail on CP/M disk sector sizes (from Jeffrey Worleyhttps://forums.atariage.com/topic/220185-atr-8000-and-other-cpm-system-disks-here/page/14/):

Quote

The ATR-8000 uses mixed density formats. The first sector is always 128bytes (single density), the system tracks are 512byte sectors, and the rest of the disk can have 256, 512, or 1024 byte sectors depending on the option you chose during DDINIT.

 

Edited by StartedWith400
  • 5 months later...

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