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intric8
Seattle, WA, USA

Posted Fri Sep 18, 2020 1:10 pm

A while back I got a very strange and unusual 3rd party device with an Amiga 500 haul I'd purchased through Reddit.

The haul included a boxed, minty very early A500, an A590 and a really large pizza box sized metallic thing with a very large, heavy and kind of scary looking PSU.

I've kept the A500, but ultimately decided to sell the hard drive and strange pizza box thing.

It took my local friend Christian, who is a walking Book of Amiga Hardware, to identify it. It's called the Pacific Peripherals SubSystem 500.
Screen Shot 2020-09-16 at 4.53.35 PM.png

In case that print is tough to read, here are the details.
  • 2× Zorro II slots with DMA support
  • 1× 3.5" drive bay for an optional 2nd floppy drive
  • external power supply
  • connects to the side expansion port
  • fits under the Amiga
IMG_9551.jpg
It's a painted metal case, so it'll never turn yellow.

IMG_9552.jpg
IMG_9553.jpg
Image from iOS (1).jpg
Naked and exposed.

IMG_9555.jpg
IMG_9556.jpg
Check out the wacky power connector. Is that for a C64? Nope.

IMG_9557.jpg

Mine is the "premium" version with the extra DF1: 3.5" floppy drive that originally retailed for a whopping $399 back in 1987/88 (approximately $875 in 2020 dollars).

in theory you could eliminate a large external hard drive (like the A590, or GVP Impact HD8+) and use a SCSI Zorro II card to have an internal hard drive and reclaim some of that desk space. It had metal plates on the back for mounting additional ports, too, in case you wanted to use even more devices.

But, the side expansion connector also had a hard pass-through so you could use your pre-existing external HDD if you wanted to, which is just nuts. You'd probably have to put a book under it, though, and maybe even decide to raise your desk chair a couple of inches along the way. Hah!

In any case, this is the only one of these I've ever seen. But I was too chicken to ever try and hook it all up. I've decided that's a fun project someone else should enjoy. The PSU weighs a respectable 13.5 pounds!

I did want to capture several photos of it, first, before I said good-bye.

User avatar
BloodyCactus
Lexington VA

Posted Sat Sep 19, 2020 2:14 pm

Ha! I was about to say, I just saw this thing on ebay... and yeah lol.

Id be curious to know how they got two zorro ii slots working with dma on the 500, I didnt think it had the chips for bus for it to work correctly.

User avatar
McTrinsic

Posted Sun Sep 20, 2020 12:39 am

Same here. I am sure they don’t support DMA. Maybe they tried to bury something like ‚one of the cards may be DMA and two cards in total are possible‘ in the advertising speech.

Great idea, to be fair.

User avatar
Christian

Posted Sun Sep 20, 2020 9:30 pm

It is possible to build an expansion board that supports Zorro 2 DMA. That’s exactly what the A2000A is - an A1000 with an Zorro 2 bus board added on the same PCB.
You can have multiple external DMA devices if the bus board adds the necessary arbitration logic (this is described in the A500/A2000 Technical Reference Manual)

What won’t work is an external accelerator and an external DMA device (well, it will work if the accelerator is closer to the computer and if they are doing some tricks - see GVP A530 which is an external accelerator + SCSI DMA host adapter). For that to work in a generalized way, you’d need the A2000B coprocessor interface which the A500/A1000 do not have.

User avatar
McTrinsic

Posted Sun Sep 20, 2020 11:37 pm

Sorry if I wasn’t precise. I am aware that it’s possible. I don’t think they managed to do this with this board.

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intric8
Seattle, WA, USA

Posted Mon Sep 21, 2020 8:46 pm

For those with engineering expertise that may find this interesting.
Attachments
subsysChips.jpg

User avatar
Christian

Posted Tue Sep 22, 2020 10:21 am

Most of that logic (the NAND 7438 and the Flip Flop 7474) are used to generate the ID stream bit pattern for the floppy drive. it is the same logic that you see in an A1010, A1011 and other external Amiga floppy drives.

No logic for buffering the bus nor for handling multiple DMA cards.

User avatar
Seb132
Gold Coast, Australia

Posted Sat Jan 30, 2021 1:54 am

Would it be possible that you sold it to someone in Australia ?
Cause I could well be this "someone"... :D

User avatar
intric8
Seattle, WA, USA

Posted Sat Jan 30, 2021 9:25 am

I could have sworn I sold it to someone in Norway or somewhere in that general area. I would look it up, but Ebay only lets me go back 90 days, which is completely stupid.

But perhaps they sold it to you? I'm based in Seattle, Washington.

User avatar
Seb132
Gold Coast, Australia

Posted Sat Jan 30, 2021 9:48 pm

Perhaps it wasn't yours, then. The pictures on eBay of mine were much dirtier, with rusty screws, etc.

I did a nice refurbishment of it with, to begin, the integration of a mini industrial PSU inside the case because I didn't have the enormous PSU with it when I bought it.

I have an unfinished thread presenting it on Amibay:
http://www.amibay.com/showthread.php?10 ... eripherals

The funny bit with that device is the backplates to attach Zorro II boards is a mystery to me... Not sure how a PCI bracket would fit! My intention if (when!) I'll be using it will be to water jet cut the existing blank plates, in accordance with the boards I'll install. At this stage I'm thinking about a remade PicassoII graphic board from Matze and perhaps a SCSI controller from A2000 with an external SCSI connector...

Another cool thing is the Zorro passthrough... I wonder if a A570 CD-Rom would work too, with it. I'm not sure the memory addresses would be in conflict with any of the internal Zorro boards...
Last edited by Seb132 on Sat Jan 30, 2021 10:22 pm, edited 1 time in total.





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