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

T

TRS-Ian

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Yesterday I finally connected FreHD to the Model 16B via the Type 2 HDC.

As you will see in the video, all was going fine until the reboot at the end, and the system just locks up while loading the OS.


I used FreHD firmware 2.14, a special version of the FreHD GAL which has all the extra features of FreHD removed (essentially making FreHD a pure hard drive with no RTC, etc.) The DOS used is TRSDOS 2.0 with Hard Drive Initialisation 4.1

Does anyone know for sure whether this DOS is for an 8meg drive? It counts cylinders up to 1024 which is confusing..

I may need a more up to date DOS... TRSDOS 2.0 / HD Init 4.1 dates back to 1981/82 so maybe something newer?

Any thoughts or tech help would be much appreciated.

Ian.
 
Thanks Mike, I also have that but it lacks HD drivers. It would be good to get it going so that it's consistent with other TRS-80s, but I think the first step is to get it running as a TRSDOS system.

For people who want to try to replicate the computer/FreHD setup, you need to burn a new GAL with the jed file HERE: FreHD_MII-2nd.jed

And update the PIC firmware to 2.14: FreHD_214.hex

Ian.
 
Hi Ian

Great job you have done so far. :) I was thinking about this way of attacking this problem for a long time.
I'am searching for more than half a year for a Type II HDC.
It seems to me that they are very hard to find, or not at all.

If you succeed in getting it to work, have you thought about duplicating the HDC, as without it
there will be very few intrest in starting to participate in this project.

I was thinking about a different approach as the Type II HDC controller, as you have proven, is a duplicate of
the model 4 HD interface.

If you use the El-Cheapo interface, I think it would be much easier to connect it to the Model II up to the model 16.
All the operating systems has harddisk support in it, and the software to use it is very much available.

There is many harddisk setup software, format software and utilities.
There is more knowhow available at many users.

I think this whole project needs a easy way to get a model II HDC type 2.

I whish you a lot of succes with this project. :D
 
A couple of suggestions. Can you try one of the Z80 CP/M boot disks like Lifeboat or P&T? If I recall, trsdos was rather picky about hard drive geometry. Can you force it to 6 heads 306 cylinders and try again?

Edit: This version of TRS-DOS may only support 8 meg disk geometry. Try this (from the manual):
Code: 
HARD DISK 

The TRS-80 Hard Disk Drive is organized into 256 
"cylinders". Each cylinder is made up of four tracks that 
have the same radius on each of the four surfaces (4 * 256= 
1024 total tracks per hard disk). 

Each track contains 34 sectors, numbered 1-34. Each sector 
contains 256 bytes. 

The total capacity of a hard disk is: 

(1024 * 34 * 256) = 8,912,896 bytes
TRSDOS-II supports arbitrary hard drives using the FORMAT command. See http://www.vintagecomputer.net/fjkraan/comp/trs80m2/doc/TRSDOS-II_RefMan_1-2.pdf, page 74 of the PDF.
 
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Hans01 said:
If you succeed in getting it to work, have you thought about duplicating the HDC, as without it
there will be very few intrest in starting to participate in this project.
Click to expand...

I have to concur with Hans. Although, I say full speed ahead Ian, this is an awesome first step and I am sure to buy one, i have yet to find a HDC for my Model II. Finding the hard drives has been easier than the controller.
 
The type 2 HDC looks pretty simple. I'll have to pull the tech ref for it and confirm. Looks like a CTC, 16k of RAM and some glue to hold it all together. Thoughts?
 
I'm a little confused by what I'm seeing in this video. I'm still relatively new to the Model II world, so please bear with me.

I see the system in the video is running TRSDOS 2.0a. From what I've read, TRSDOS 2.0a did not support hard drives. In fact, I've read in the manuals that the thinline drives on the Model 12/16/6000 required TRSDOS 2.0b due to the fact that the drives don't run continuously.

Model IIs supposedly require TRSDOS-HD for harddrive support or TRSDOS-II 4.x for HD support on an 68k upgraded Model II/12 or 16/6000.

Am I correct in my understanding?

Update: After a little more research I see now why you could format and build a HD using TRS-DOS 2.0 as depicted in Ian's video. Apparently the 4.0 versions of TRSDOS-II required the HD to be setup using TRSDOS 2.0 before installing TRSDOS-II. 4.2 and later TRSDOS-II did not have this limitation.

See http://fjkraan.home.xs4all.nl/comp/trs80m2/TRSDOS_versions.txt
 
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Yes, early days at the moment.

My knowledge and resources (more on that below) are rather limited compared to the I/III/4 systems so this project will require much more collaboration from you good forum members as I learn about these systems at the same time as experimenting with details until it works. Yesterdays video is just the start.

Re. Type 2 HDC, yep - it's a rare one, which makes this project more of a "I just want to see it work" rather than a volume seller that every user can just buy and plug in. Most enthusiasts who have acquired 8in systems over the years have the Type 2 HDC in their collection, some may not even know it's in there. I feel sorry for those 8in enthusiasts who are starting out collecting now, as they are expensive to buy and are easily damaged in transit. Even more so as the plastic cases get brittle with age. I have looked at the Type 2 HDC but it's just too sophisticated to reverse engineer and build new ones at anything approaching reasonable costs. Type 2 HDC contains some 40 ICs, one of which being a hard-to-find Z80A CTC.

Re. Resources: To start the testing I can logically only start with what disks I have on hand. So the first test is done with the only TRSDOS HD disk I had, which the more I look into it seems to be related to the old 8meg hard drives. It's a promising start, but I need to obtain newer versions of the operating systems, to proceed further. I have been reliably tipped that I need 4.2.1 , or .3, .5, .7, .9 which are the versions for the WD1010 HDDs which FreHD emulates.

Anyone able to ship me a copy of the 4.2.x OS?

Cheers,

Ian.
 
I think the route with the El-Cheapo (interface from Lo-Tech) offers a good starting point.

The 80 Lines system bus of the Model II to 16B offers all the lines to create a 40 pens
IDE connection.

Just a double sided prototype board with a bus connector of the right size (who knows where to buy it) and
a 40 pin male connector and 40 wires to connect with the bus.

Use LS-Dos 6.3.1.a and take the drivers and software from the Model 4P project and give it a try.
Yes, at first no autoboot, but if it is working, somebody would take a look to fix it :)

It solves the problem of the need of a Model II HDC type 2.
And a pcb can be easily produced if it is working. (I have seen beautiful examples on this forum) :)

If I can find a good prototype board i'll surely give it a try.

Just tell me what is wrong with this idea ?
 
Hans01 said:
Just tell me what is wrong with this idea ?
Click to expand...
Would that approach work with Xenix, CP/Mor TRS-DOS? If not then that's what's wrong.

If would also work for those, then nothing as far as I can see.

There is very little LS-DOS support for the model II family. There are more CP/M and Xenix sources than LS-DOS.

Didn't have time to look at the controllers I have or the tech reference last night. Will try to remember tonight.

For what it's worth, I have plenty of type 2 controllers. I also have quite a few of the last type that talks to the mfm drives directly.
 
+1 to kb2syd

A Model 2/16 <> Model 1/3/4. They are built for entirely different purposes and had entirely different and non-compatible software. The Model 2 series used TRSDOS, CP/M and Xenix (with the optional 68000 + memory card) and the solution has to skew to that. Not attempt to make a Model 2 series work like a Model 1. Even Tandy didn't do that.

Myles
 
@kb2syd

Would that approach work with Xenix, CP/Mor TRS-DOS? If not then that's what's wrong.

If would also work for those, then nothing as far as I can see..
Click to expand...

I don't know, it's a project of Ian and I only made this suggestion.
It depends on the availabilety of drivers.
There is LSDos 6.3.1.a which should run on all the Models II to 16B
This software is very close to LSDos 6.31. for Model 4P.
There are drivers for LSDos 6.3.1, TRS Dos 6.2, CP/M and more which are patched to use for the Lo-Tech IDE controller.
This is a good startingpoint to try to make them run on the Model II's
If these drivers are suitable for the Lo-Tech IDE interface
or can be patched must be checked after the hardware for the interface is made to work.[/QUOTE]

Didn't have time to look at the controllers I have or the tech reference last night. Will try to remember tonight.

For what it's worth, I have plenty of type 2 controllers. I also have quite a few of the last type that talks to the mfm drives directly.
Click to expand...

If you find some useful information please make it available to all of us, it could help a lot.
If you have a spare Type 2 controller and do not need it, please let me know, i'am very intrested to buy it

Hans.
 
TRS-Ian said:
Thanks Mike, I also have that but it lacks HD drivers. It would be good to get it going so that it's consistent with other TRS-80s, but I think the first step is to get it running as a TRSDOS system.
Click to expand...

Ian, one of the three images Tim Mann put up, that I sent him back in 2000, definitely has the TRSHD2/DCT driver and the TRSFORM2/CMD formatter. I think it's the double-sided one. Hmm, the single-sided has a generic 'WD/DCT' but I'm not sure of the lineage of that file. Here's a screenshot from MESS in Model II mode of a CAT :0 (S,I) booted from the single-sided LS-DOS 6.3.1A image I sent to Tim (the double-sided image won't boot on MESS yet):
ls-dos631-ss-cat-m2-20150304-.jpg

I can send you the files pulled from the double-sided image; or you can do it by using xtrs with Tim's eight inch driver and booting in model 4 mode. I haven't rebuilt sdltrs for CentOS 7 yet, as I've not needed it since I migrated to C7, but I may have the files pulled out somewhere.

At least you'd be working with familiar code and a familiar, if a bit buggy, OS. LS-DOS 6.3.1A for the 2/12 was not the most stable thing in the world. EDIT: m2-hd.zip contains the binaries for trshd2/dct and trsform2/cmd, as well as the commented source code from the LS-DOS 6.2 sources.

EDIT: Here's what an attempt to boot the double-sided image looks like..... Error 05H is Data record not found during read. It does this even if I abort the sysgen. It may be that the trs80m2 MESS can't handle double-sided; I've not debugged to that level yet. And setting up MESS with two drives, then trying to pull a directory from the DS disk yields 'Directory read error' but it works fine from the sdltrs/xtrs Model 4 mode with the xtrs eight inch driver.
ls-dos631-ss-cat-m2-20150304-3.jpg

EDIT: Ah, I did rebuilt SDLTRS for C7..... here's a cat of the LS-DOS 6.3.1A DS image Tim pulled from the physical 8-inch disk I sent him in 2000:
ls-dos631-ds-cat-20150304-1.jpg

But do note that those drivers are from LS-DOS 6.2, and thus are not 6.3.1 date format aware; you'll need to run DATECONV on the resulting HD.
 

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The m6000HD Part 2.pdf file as I downloaded it just contains carpet cleaning suggestions. ?!

The El-Cheapo approach might be interesting for Model II (or 12 w/ card cage option) owners, but would be kind of pointless for 16/6000 owners unless somebody writes Xenix drivers for it, in my opinion. The great advantage of FreHD is that it emulates original Tandy hardware at the interface level, so no special drivers are needed. Just having an emulated HD for LS-DOS might satisfy some folks, but the main point of the 16/6000 is to run Xenix on the 68k processor. (Was there any non-Xenix commercial software that used the 68k as a coprocessor?).

So, experimenting with an El-Cheapo like card might be a fun project, but this particular thread is focused on tweaking FreHD to work with the II/12/16/6000, using existing hardware.

Now, if it turns out that there's a significant number of II/12/16/6000 owners out there who want an emulated HD but can't find original HD controller cards in order to use FreHD, then maybe somebody would like to roll up a new plug-in card that's register-compatible with the original HD controller cards. That would be an interesting item. It's the sort of project I'd consider doing if I didn't have so many other projects in progress. :)
 
kb2syd said:
Here is what I have in the tech ref for the model 6000 HD. It is only for the last type of controller, but the ports and theory of operation is the same. Still looking for the docs for the type 2 controller.
Click to expand...

From my perusal of the LS-DOS TRSHD driver source, it appears that LS-DOS is not taking advantage of the interrupt capabilities of the WD chipset. However, the schematic shows pretty clearly that the HDINTRQ from the WD1010 is wired into the CTC for interrupt mode 2 vector generation. Since Tim Mann's WD1010 code was written primarily to do the programmed I/O that the M3/4 use, it may be that the HDINTRQ handling is either nonexistent or not well-tested.

So, Fred, Ian; how does the FreHD firmware handle HDINTRQ and are IRQ's generated at all? TRSDOS (and the Xenix z80ctl program) may use the HDC's interrupt capability in ways that the M3/4 DOSes do not. Not having a working HDINTRQ would still allow the initialization to work, if it uses programmed-I/O, but then perhaps the driver uses the interrupt facility after it tries to boot.

EDIT: From the 2.14 sources, I see the following line in release/pic/trs_hard.h:
Code: 
#define TRS_HARD_INTRQ			0x01 /* not emulated */
so I'm taking that at face value.

And thanks, kb2syd, for posting those pages of the 6000 SM.
 
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