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FreHD on Model II/12/16/16B/6000 - FIRST ATTEMPT

Gentlemen,

The aim here is to see who can get a modern digital storage device working on these machines... I am most familiar with FreHD so that is why I look at the problem from that angle, however I have much respect for Hans01's work with the Cheapo-IDE and if that is the best angle for him to work from then I encourage him in his work. Its very possible that if Cheapo-IDE can be made to work, the solution will be a lot less expensive than a FreHD solution.

Hans if you need anything from me to get started, let me know.

@lowen, that's great to hear about the HDINTRQ, let me run it by Fred and Andrew.

Cheers,

Ian.
 
TRS-Ian said:
Gentlemen,

The aim here is to see who can get a modern digital storage device working on these machines... I am most familiar with FreHD so that is why I look at the problem from that angle, however I have much respect for Hans01's work with the Cheapo-IDE and if that is the best angle for him to work from then I encourage him in his work. Its very possible that if Cheapo-IDE can be made to work, the solution will be a lot less expensive than a FreHD solution....
Click to expand...

There is an INTRQ line in the ATA standard; I would have to wonder if the semantics of that IRQ are similar enough to work. Does the Cheap-O board provide continuity of the IRQ? (I'll look myself in a bit.....)
 
Just noticed something on the Type 2 HDC which may be important, there are heaps of jumpers on the board...

type2hdc.jpg

Can anyone provide a description of what they all do and why?

Cheers,

Ian.
 
TRS-Ian said:
Gentlemen,

The aim here is to see who can get a modern digital storage device working on these machines... I am most familiar with FreHD so that is why I look at the problem from that angle, however I have much respect for Hans01's work with the Cheapo-IDE and if that is the best angle for him to work from then I encourage him in his work. Its very possible that if Cheapo-IDE can be made to work, the solution will be a lot less expensive than a FreHD solution.

Hans if you need anything from me to get started, let me know.

Ian.
Click to expand...

@Ian.

I hope we both succeed in finding a way to connect a modern harddisk solution to a Model II series computer.
It would give the serious user a professional solution for a professional price or a hobby collector a interchangeable
solution with some or more restrictions.

For the moment I need a double sided prototype board with a Model II bus connector.
I'am afraid that this not exist, but you know so much about TRS 80, I hope you can point me in the right direction.
Or maybe you can help me with a destroyed and useless model II board where I can cut off the edge connector and some traces.
 
TRS-Ian said:
Just noticed something on the Type 2 HDC which may be important, there are heaps of jumpers on the board...

Can anyone provide a description of what they all do and why?
Click to expand...
They're pretty simple. They set the RAM address and the port address. Pulls up input of U26 and U1.
From notejump.pdf page 221 and 222

Model II/16/16B/6000
ModelII-6000.PNG

Model II/16/16B/6000
Model12.jpg
 
Hans01 said:
For the moment I need a double sided prototype board with a Model II bus connector.
I'm afraid that this not exist, but you know so much about TRS 80,
Click to expand...
What about a quick layout for one of the inexpensive FAB houses like OSHPark.COM? I bet we could get NF6X to lay it out for us. I'd buy a couple to play with.
 
kb2syd said:
What about a quick layout for one of the inexpensive FAB houses like OSHPark.COM? I bet we could get NF6X to lay it out for us. I'd buy a couple to play with.
Click to expand...

A full-sized Model II/12/16/6000 card is 10" x 5.5". That would cost $91 each at OSH Park in the 2-layer standard run (must order multiples of 3 boards). It could be dropped to $55 each using their 2-layer medium run (must order multiples of 10 boards, and not web-orderable).
 
NF6X said:
A full-sized Model II/12/16/6000 card is 10" x 5.5". That would cost $91 each at OSH Park in the 2-layer standard run (must order multiples of 3 boards). It could be dropped to $55 each using their 2-layer medium run (must order multiples of 10 boards, and not web-orderable).
Click to expand...
What about just fingers and 80 plated through holes? Say 10" x 1.5" just so we can prototype some stuff. Or even smaller, like just the board edge and enough to insert and remove.

Personally, I'd be good with $91.
 
That would drop the price quite a bit. It would then cost $25 per board (must order multiples of 3) in standard run, or $15 each (must order multiples of 10) in the medium run.

Note well: Those are the raw board prices if you order directly from OSH Park, and you would need to order 3 or 10 boards at a time to get those prices. If I was to quit my day job and sell these boards, then multiply everything by 2.5 and add shipping. And I'll need y'all to order 8,000-10,000 boards per year so I can quit my day job. :D
 
NF6X said:
Note well: Those are the raw board prices if you order directly from OSH Park, and you would need to order 3 or 10 boards at a time to get those prices. If I was to quit my day job and sell these boards, then multiply everything by 2.5 and add shipping. And I'll need y'all to order 8,000-10,000 boards per year so I can quit my day job. :D
Click to expand...
I know how it works, I just don't know how to get the layout done. There are other houses with other limits, but I like the CoCo work you did through OSH Park and I love the way they communicate.
 
I'd enjoy whipping this board out (I'd make the bus connection points match header footprints for my HP logic analyzer), but it's way down on my project list at this time. If you don't want to wait many months, then it would be a good excuse to learn how to lay out a board... ;)
 
NF6X said:
I'd enjoy whipping this board out (I'd make the bus connection points match header footprints for my HP logic analyzer), but it's way down on my project list at this time. If you don't want to wait many months, then it would be a good excuse to learn how to lay out a board... ;)
Click to expand...
What do you use for layout?
 
I previously used Eagle (non-free version, and I think this board would be too large for the free version). I've recently switched to Kicad.

Seriously, this is exactly the sort of project that interests me. But my day job is kicking my butt in terms of time and energy, and I have another project which has a hard time limit (must be ready by an event at the beginning of May), and even that is going to be tough.

Sigh.
 
@NF6X, kb2syd, Ian and all the others.

I previously used Eagle (non-free version, and I think this board would be too large for the free version). I've recently switched to Kicad.

Seriously, this is exactly the sort of project that interests me. But my day job is kicking my butt in terms of time and energy, and I have another project which has a hard time limit (must be ready by an event at the beginning of May), and even that is going to be tough.

Sigh.
Click to expand...

I think that the production of a small pcb to insert in the expansion bus is a good idea. It is a pity that NF6X has no time at the moment.
Take a look at the small drawing, showing the idea.
The PCB must be cheap, as it is only for development.
But some things must be arranged first.

Who can and will arrange the production of the small board.
How many people want such a board to participate in the project. (count me in for two)
Who will finance the pcb at first and collect the money from the buyers

Please keep in mind:

It is not certain that it will work.
If it works, there must be designed a new and better layout for the board.
And absolutely no guaranty.


card.jpg
 
A PCB like Hans01 suggested would be a bit cheaper than a full 10" wide board, at the expense of not engaging the card guides and being insertable upside-down. For small-run houses like OSH Park, cost is proportional 1:1 to the area of the smallest rectangle that bounds the board.
 
Just want to chip in here and say I am interested in acquisition of one of these solutions. I have just paid for a Model II and it will be here next week. Can't wait. First order of business will be lugging it up the stairs.. ha ha... :crazy:

Now, I already have a 128k NGA M4 complete with Lo-Tech IDE solution that works really well, and I'd love one for the Model II. The limitations of using this over the FreHD are acceptable to me as I can do what I did with the M4 and transfer via a PC and 3.25" disks plugged into the external drive connector, or with a SD Emulator spliced into the internal drive cable. I imagine my Model II has no HDD card so this means I will not be able to use FreHD anyway, is that correct?

@Hans - Happy to assist in any way I can!
 
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@JonB

I'am still working on the Lo-Tech project.
I had to wait for a busconnector which Ian has arranged for me. (Thanks Ian)
I have setup the IDE interface for a connection to the Model II system bus.
I can address the card with the Lo-Tech software but run into some problems.
Who have the answers. I'am setting up normal port I/O.

Do I have to have to turn around the daisy chain signal IEIN to IEOUT
Do I have to turn around BAKIN to BAKOUT or can I ignore these signals and don't need to turn around them.
Must the I/O card the last one in the cardcage and should in be the next one after the default boards.
Can I use the EXTIOSEL* signal from the Lo-Tech for the SELECT* signal.
Some helpfull suggestions.
 
Well, My MII arrived today and what a beast it is. I'd forgotten how HUGE and HEAVY it is - especially that 8" drive.

So, I have a four card machine with 64k. No hard drive controller.

Your questions - I don't have the answers but I bet someone else does!

Cheers
JonB
 
Hans01 said:
@JonB

I'am still working on the Lo-Tech project.
I had to wait for a busconnector which Ian has arranged for me. (Thanks Ian)
Click to expand...

Hans, when you say 'busconnector' what exactly are you talking about? Is this a full hard drive interface card, or just the bare card edge?
I have setup the IDE interface for a connection to the Model II system bus.
I can address the card with the Lo-Tech software but run into some problems.
Who have the answers. I'am setting up normal port I/O.

Do I have to have to turn around the daisy chain signal IEIN to IEOUT
Do I have to turn around BAKIN to BAKOUT or can I ignore these signals and don't need to turn around them.
Must the I/O card the last one in the cardcage and should in be the next one after the default boards.
Can I use the EXTIOSEL* signal from the Lo-Tech for the SELECT* signal.
Some helpfull suggestions.
Click to expand...

The Model II is a Z80 IM 2 machine, and this is critical. If the card in question uses interrupts you must properly tie in to the Z80 interrupt daisy chain, and you must provide a Mode 2 interrupt vector; this is the purpose of that Z80 CTC on the hard disk interface card, as the driver would program the CTC to pop the vector on the bus at the right time when getting an IRQ from the controller. I would put it in the system in the same place as the HD interface was supposed to go; I'll look for the card order in a bit and edit this post when I have a moment to look for that information. I'm not sure about the BAKIN and BAKOUT signals, but I want to say those are for DMA.

Now, if you want to use it with LS-DOS for testing rather than TRSDOS or Xenix, you might be able to forgo the interrupt logic completely, and the exact same driver for the LO-Tech as used for the Model 4 should work unmodified, since the LS-DOS WD driver doesn't use the WD1010's interrupt facility.

It sure would be nice if those long-lost schematics for the hard disk interface were to show up. Barring that, look closely at the schematic for the integrated hard disk interface/controller that was previously posted, and see how the WD1010 subsystem is interfaced to the card edge.

EDIT: Card order, from a comp.sys.tandy posting:
There are
6 boards in a stock non-hd model 16a. They are (from left to right standing
at the keyboard) The z80CPU, the disk controller, the video card, 64K z80
memory, (spaces in here probably) 68K memory, 68K board. If there is an
HD interface, it gets wedged in between the FDC and the video card.
Click to expand...

As I recall that's correct, but I'll reserve the right to be wrong.
 
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