Atari & 3rd Party Floppy Drives - Hardware Specs

[+MrFish]

If anyone can answer any of the following questions concerning Atari and 3rd Party floppy drive hardware for our 8-bits, I would appreciate it. The information is needed for continued construction of my forthcoming hardware site.

 

I don't own any of the following hardware, otherwise I'd tear is apart and find out the needed info. The Atari 8-bit FAQ has already been searched, as well as whatever information might be available on Atariage and other sites on the net.

 

Atari 810
Manufactured in Sunnyvale?
Micro Peripherals mech part #?

 

Atari 1050
Western Storage Technology mech part #?

 

Rana 1000
RAM size?
Micro Peripherals mech part #?

 

Percom AT-88
Tandon & Micro Peripherals mech part #'s?

 

Amdek AMDC I/II
RAM size?
Drive mech?
 

Edited August 23, 2021 by MrFish

[+Nezgar]

Atari 810: I think of these in three "generations": (lots of good details in the Atari 8-bit FAQ on the 810's)

 

1. "810M Pre-analog" Earliest drives Winter 80-Sep 81 - MPI mech, no external data separator, no separate analog board, weak PSU prone to failure and RPM instability, and Rev B ROM that formatted with slow 13:1 best for DOS 1.0's lack of burst I/O.
2. "810M Analog" "Grass Valley" upgraded drives - Sep 81 - Nov 82 - Upgraded PSU based on 7805/7812 voltage regulators, Rev C ROM, data separator, separate analog board.
3. "810T" Tandon drives - Nov 82 - May 1983

810 Tandon mech is a bare TM-100 with a lot of the standard electronics removed.

 

Atari 1050 - 2 revisions:

• May 1983 to December 1984: bare Tandon TM-50 Mech, Made in Singapore, ROMs with Revs E, F, H, J, K L known,
• November 1984 to February 1985: WST (World (not Western) Storage Technologies mech, Made in Hong Kong. Modified rev K ROM on EPROM with adjusted stepper phase positions and step timing

 

I'll inspect my drives above for specific more mech part #'s and lookup what info I can find on the Rana, Percom, Amdek.

[+MrFish]

43 minutes ago, Nezgar said:

Atari 810: I think of these in three "generations": (lots of good details in the FAQ on the 810's) I will inspect a mech and get you a part number.

 

I'll inspect my drives above for specific more mech part #'s and lookup what info I can find on the Rana, Percom, Amdek.

 

"Lots of details", yes; but I just need the specific info I'm posting about. I already have the Tandon mech part numbers for the 810, 1050, & Indus. The only Tandon I'm posting about is for the Percoms.

 

If you get time to check out some of your drives for the other info, that would be great. Thanks.

 

[Atari8guy]

I’ve got a boxed Rana 1000. If Nezgar can’t find anything on it online I’ll dig it out of the crawl space.


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[xrbrevin]

Indus GT uses a Tandon mech and a Z80 CPU

Rana 1000 has 2 versions. 1 uses an Intel CPU and the other a 6502

LDW super 2000 uses a Roctec mech and has a Z80 CPU

[phaeron]

5 hours ago, MrFish said:

Amdek AMDC I/II

 

RAM size?

AMDC has 1KB of RAM.

[+MrFish]

4 hours ago, phaeron said:

AMDC has 1KB of RAM.

 

Ah, that's like the 4th line in your disassembly. I didn't think about looking in there. Thanks!

 

Alright, that's one down...

 

Edited August 21, 2021 by MrFish

[BillC]

On 8/20/2021 at 4:51 PM, MrFish said:

The only Tandon I'm posting about is for the Percoms.

The following is from my Percom AT88-S1 mechanism, this is a SSSD drive. It has a PCB attached to the top with a 34-conductor edge connector, there is also another PCB attached to the rear that appears to control the drive motor

 

Edited August 22, 2021 by BillC

[+MrFish]

4 hours ago, BillC said:

The following is from my Percom AT88-S1 mechanism, this is a SSSD drive. It has a PCB attached to the top with a 34-conductor edge connector, there is also another PCB attached to the rear that appears to control the drive motor

 

Alright, as I suspected, same as in an Atari 810.

 

Thanks for checking it out for me.

 

[+Nezgar]

Some digging and dissasembling this evening.... First up we have three 810's with MPI mechs. Apparently 51 was the single sided model, 52 was the double sided model:

https://archive.org/details/bitsavers_mpibrochurre_816309/page/n1/mode/1up

 

#1 is an early 1980 unit, pre-analog/grass valley board set. Model # "B51", low serial number (especially compared to the 1983-84 model in my Percom at almost 900000), sticker on back:

 

#2 has a July 81 Mfg date model "51M", sticker underneath so a bit of disassembly required to see:

 

#3 Nov 1982, "51A" (wonder what the letters mean)

 

Now onto my Percom AT88-S1. Also has a similar "51S", but the percom mechs have all the standard PC supporting hardware still attached, unlike the 810 mechs. I believe thats Oct 83, since there's a sticker elsewhere on the same mech that says Feb 20, 1984 - maybe when it was QC checked. Most of the PCB's have 83 dates. According to the following post by @JR>, 2 AT88 S1PD's had a World Storage Technology (WST) FDD 112-5 03 Mech (Like the made in Hong Kong 1050's) the other had a Micro Peripherials Inc. (MPI) 501c (like the RANA):

https://atariage.com/forums/topic/283450-percom-rfd40-s1/?do=findComment&comment=4127830

 

One of my "Made in Hong Kong" 1050's with a World Storage Technologies mech. Model FDD 112-5. Looks like the double-sided variant is FDD 212-5, as pictured on this electronics recycling site:https://www.recycledgoods.com/world-storage-technology-fdd-212-5-5-25-floppy-disk-drive/

 

Lastly, my Rana 1000 - an MPI 501C, Mfg date Jan 1984. This particular RANA has a 6502 CPU, a 2732 EPROM (so 4KB ROM) and 2xMCM2114 SRAM chips. 4096 bits x 4 each, together these provide 1024x8 (1KB) of RAM.

 

I also have a TRAK AT-D1 ... are you interested in that? I need to pull it out at some point to dump the ROM there too... Maybe it has the same mech as the RANA.

[+MrFish]

Wow! Thanks for ripping all that stuff up. That's a big help getting some of the last details needed.

 

I'll make another reply tomorrow when I've had some sleep and can say something more coherent.

 

But, quickly... as for the Trak AT series, I got Teac FD-55A from somewhere; but at the moment, I'm not sure if that holds for all models or not... (something else to look into in the morning/afternoon).

 

[+MrFish]

@Nezgar

It looks like that covers everything I was looking for -- except the Amdek, which is a rare bird (maybe @bf2k+ can help out there -- if he still owns his).

 

I think I'll just stick to the Percom AT-88S1's for now (I need some cut-off points for launching the site); but thanks for the heads up about @JR>'s AT-88S1PD drives. I see another one posted here (even though the manual displayed is for the AT-88SPD) Percom AT-88S1PD, which also has a half-height drive. Either the Atari 8-bit FAQ is wrong (states they should be full-height drives), or Percom made them with both half and full height?

 

No rush on opening the Trak drive; but I will be curious if it matches the drive I currently have listed (Teac FD-55A).

 

Edited August 23, 2021 by MrFish

[+MrFish]

I found this while searching for some information on the mpi 51-52 drives.

 

It wasn't bookmarked when I found it; but lo and behold...

 

This is some of the type of reference materials that are going to be on my site. Something like this would show up in a section for any drive where this mech is an option. I'm saving most of these for the site launch, of course; but here's one ahead of time.

 

 

MPI Model 51-52 - Manual.pdf