TRS 80 Model II LoTech adapter board - Beta

[Hans01]

Yes, probably, but it is not tested.
Only for the file system from LSDOS would it be possible to exchange data.
Not tested too !!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[TRS-Ian]

Here's one I prepared earlier in case you were wondering what your $25 buys you:



Cheers,

Ian.

 

[Hans01]

Connecting the hans01 with the lo-tech-ide.

Use some isolating marerial like perspex or a blank PCB covered with isolation tape.

 

[pearce_jj]

To support Hans' project, more TRS-80 PCBs are now available here.

 

[Hans01]

Hassle free data exchange between a Model 4(p) and the Model II family.

With the hans-01 it is very easy to exchange data between the two family's of tandy's
What you need is LSDOS 6.3.1 (a) for Model 4 and for model II
Use a DOM to make it easier.
Connect the hans-01 with the Model II and setup a boot disk following thread #18.
Add all the data you want to exchange in one or more partitions. (CMD; TXT; SYS; anything you want)

Remove the hans-01 and change U2 to a 74HCT640 or buy a second Lo-Tech ide adapter.

Connect the Lo-Tech adapter with a Model 4(p) and setup a bootdisk with the same parameters as shown in thread #18,
but don't format. Do a sysgen and reboot.
Now you can read, write, delete and execute all the data on the DOM.

This can be done in the same way to send data from the Model 4 to the Model II
Don't forget to change the IC U2 to the 74HCT245

There is list on internet with patch data to make Model 4 software running on Model II's

That's all. :D

 

[pearce_jj]

Possibly, a Rev.3 board will include compatibility modes for both boards to save on changing the IC, if there is demand.

 

[Hans01]

Hi James.

I like the idea, count me in.

Hans01

 

[pski]

I am close but I am having some issue testing my Hans01.

I have built a LoTech adapter as per the Lo-Tech Wiki.




and purchased a Hans01 adapter from TRS-Ian. I have installed the Hans01 and attached 5v.



I have the HxC as disk 0 with the Hans01 IMD installed



The system boots into LDOS normally after pressing REPEAT-BREAK, but then the HxC tells me I need to select a disk again and I start getting 11H errors



Any ideas?

Thanks!

EDIT: Ok, nevermind. When the HxC tells me I need to reselect the disk again, if I select it fast enough I don't get the 11H error but go right into the LSDOS prompt. I will continue from here and update you on my progress.

 

[pski]

Ok, the 11H error went away once I disabled drive B on the HxC. That's another issue for another day.

Now, I am hanging during the driver routine. After entering the starting head = 1, the system hangs.



Thoughts?

I'm going to try hooking up the LoTech to a Model 4 and see if it works so as to remove that as a possible suspect.

 

[Audronic]

Hi Pski

Do you have an old version of a CF Card (smaller capacity) or a small DOM (128 Meg).
We had some drama's with the model 4p some time ago using 4 gig CF Cards ??.
Just a thought ??

Ray

 

[Hans01]

@Pete.

Have you changed the U2 chip on the Low-Tech from a 74HCT245 to a 74HCT640
The power connector on the hans-01 is an output to supply the ide-adapter with 5 volt power (if you need it)
If you have fixed the ide-adapter together with the hans-01 be careful not to make a shortcut with some traces of the hans-01

The hans-01 is tested on a Model II and a Model 12

The hans-01 is tested with a 128 Mb DOM, several 2.5 harddisks, SD cards up to 4 Gb. which all works on a Model4P.

Just as Ray mentioned a CF card (mostly) didn't work nor on a Model II nor on a Model4P.


Here they are very cheap (about one euro)
http://www.pollin.de/shop/dt/OTAyOD...platten_SSD/DiskOnModule_PQI_IDE_128_MB.html…

 

[Audronic]

@ Pete

The DOMs from Pollin.DE are cheap
BUT Please check the Postage, from Pollin to Australia it was Very high the last time i looked ??? 50-90 Euro ???.
Hope that this helps.

(Text edited)
Below is the query i sent Pollin about Postage.

""" Dear pollinelectronic,
Postage to Australia 59.95 Euro ???
Is this correct
Thanks Ray W"""

Ray

 

[Hans01]

@all

If there are more users who want to buy DOM's I can order a bunch of them in Germany.
(Or maybe James comes to help :wink: )
The shipping costs from there to Holland are about 11 euro.

I can ship them from Holland to users in Australia and the US.
Shipping as a small package costs about 16 euro's.

If you order more of them for future uses, I think the final price will be very reasonable.

But only once, I'am not a shop, and only,
If you all need a reasonable number of DOM's.
If you pay me with PayPal.

 

[pski]

Yes, I did swap in the appropriate U2 chip for the MII.

Regarding the 5v input...err, output...so that's why my Model II power LED was lit up with the power switch off!

I will get a 128MB DOM and report back my results.

Thanks!

 

[pski]

Ok, I finally obtained a DOM but now I'm having problems with LSDOS again. I am getting the infamous Error 11h after the date prompt. This is even without the Hans01 adapter connected. I have already disabled the HxC drive B so I guess I need to tackle this issue before moving forward. Any thoughts on what could be the problem?

 

[lowen]

LS-DOS is trying to read the command interpreter SYS file, and it's hitting a directory read error. Do you have another disk? The most typical cause for an Error 11H is improper data address marks on the directory track. Is this with an image on an HxC? If so, you can check for the proper deleted-data address marks easily enough on your PC.

For the benefit of the whole group, I just want to say that LS-DOS 6.3.1A for Model II/12 is not nor has it ever been a really stable OS. Many patches need to be made to it to make it stable; some are the same as the Model 4 version's patches to get up the level F, but some are unique to the Model II/12 hardware and have not even been developed yet.

Misosys did sell it, but I still remember the release being billed as 'unsupported.' The release of 6.3.1A for II/12 was very late in the TRS-80 lifecycle, one must remember, and by that time (1990) things were getting really slim. Now, don't get me wrong, I'm glad Roy released it. It just wasn't fully baked, especially on the Model 12/16B/6000 hardware. It needs some serious TLC by someone with the time and the hardware (you need a good working II and a good working 12/16B/6000 to do this correctly). Also note that the source for 6.3.x for the II/12 has never been fully released (there is a 6.2.0 ac beta source out there) and much reverse-engineering will have to be done to get the source up to 6.3.1A. Then you really would need to treat Frank Durda to a fancy dinner and try to get some of those undocumented hardware glitches documented (as the maintainer of z80ctl for Xenix, Frank is the authority on the hardware issues, and there are clues in his comp.sys.tandy postings to some of the misbehavior of the hardware, but it's not fully documented by any means).

While many times I wish I had kept the machines I had, I have to remind myself of all the problems I was having with them at the last (where 'the last' was 1999). The Model 12 I used to copy the LS-DOS disks I had that I sent to Tim Mann for imaging back in June of 1999 was beginning to have issues with both its TM848 drives. At that point in time neither the 16B I had nor the 6000 I had would boot.

 

[pski]

Thanks, @Iowen. I'd love to work on the LS-DOS MII project. But, it sounds like a tough, if not impossible, mountain to climb. Maybe I will look into it as I move forward. I love LDOS/LSDOS on the I/III/4 where they truly rock. However, for some reason, I do prefer TRSDOS II and Xenix on the big boxes since they are different and feel more authentic. Maybe since they were used in the trenches in the late 70s (TRSDOS) and mid-80s (Xenix) on the MII line.

I'm using the HxC. Looks like the Error 11H is an issue with Hans IMD image. I switched to the Hans HFE and LDOS works fine now. Standard LSDOS 6.1.3 image I got from bill deneg's site works fine as well. @Hans01, can you verify if the IMD is correct? I saw that @JonB had the same issue with Error 11H in an earlier post in this thread.

However, I am still hanging during the driver configuration even though I am now using a DOM.



I am going to test my LoTech on a Model 4 to make sure I built it correctly.

 

[pski]

Ok, I figured it out! I had forgotten to switch back in the 74HCT640N on the LoTech for the Model II. Oops.

All is working well now!

So, just to recap.

I followed @Hans01 instructions but had to use his HFE file, as the IMD file seems to be corrupt.
Also, make sure you use a DOM for storage. My 4GB CF card did not work.



Thank you to @Hans01, @TRS-Ian, @JonB, @pearce_jj and everyone else who worked on this project.

I declare the Hans01 adapter a success!!

 

[lowen]

Thanks, @Iowen. I'd love to work on the LS-DOS MII project. But, it sounds like a tough, if not impossible, mountain to climb.

Oh, it wouldn't be that hard; you'd just need to have reasonable Z80 skills and most importantly have the hardware in hand. It should be possible to do the build on a 4 or 4P emulated on xtrs or sdltrs and then translate the 8 inch disk image to the HxC for testing. Heh, you should be able do the build with zmac on Linux then write a small tool to do the disk compose, with a bit of source code editing to deal with some of the edas/mras-isms in the sources. The only sticky point with the compose is the image format and the boot track build, which only the Model II LS-DOS backup command does. But a 'backup2/cmd' could be built that would handle those things on the emulated 4.

Now, I'm getting up to speed on a much more difficult project right now involving LDOS 5.3.1 and a Lobo MAX-80.... maybe even a port of LS-DOS 6.3.1 to the MAX-80. And yes an HxC figures heavily into those plans. I do have hardware in hand, but I'm still studying the LDOS 5.1.3M disk images for the MAX-80 and I'm studying the hardware ref to wrap my mind around it.

Maybe I will look into it as I move forward. I love LDOS/LSDOS on the I/III/4 where they truly rock. However, for some reason, I do prefer TRSDOS II and Xenix on the big boxes since they are different and feel more authentic....

Certainly; but getting the Xenix experience is easier on a 286 or 386 these days, since the emulators are available and they work well for the 286/386-class machines later Xenix was built for. But I run Linux as my primary desktop; I have the Unix command line experience every day.

I'm using the HxC. Looks like the Error 11H is an issue with Hans IMD image. I switched to the Hans HFE and LDOS works fine now. ...

Could be just a bad image. I know the MESS/MAME trs80m2 emulator booting LS-DOS is very very finicky about the image format, with some images supporting the DDAM and some apparently not supporting it. But I've not tried it in a while, and MESS/MAME are in heavy development.

 

[Hans01]

Thank you to @Hans01, @TRS-Ian, @JonB, @pearce_jj and everyone else who worked on this project.

I declare the Hans01 adapter a success!!

@pski, I am glad to read this, it's a reward for all the time we spend on it.

I'am working at the moment at a hans-02, with the following features:

No need for chip changing if you change between a M4 and a MII.
Hardware connection for a FreHD, but only a way to connect the FreHD to a Model II, without change chips.
May be need a reprogrammed GAL and / or PIC
Jumpers to configure the interface

There is no working software for the FreHD at the moment, but it must be possible to patch existing software.

I have DOSPLUS IV running on the Lo-Tech adapter on a Model 4.
I have DOSPLUS II running on the Lo-Tech + hans-02, but the data is corrupted because the driver must be patched too.

The hans-02 is ment for users who want to solve the software problems to make it a succes.