Re: [M100] Annotated disassemble of T102 rom

[Erik van der Tier]

Great, thanks! Your comments are really helping with the process of translating 
to a full assembly file, especially for finding logical names for ‘intra 
routine’ labels.
I see that in this version you’ve also documented the ’split-instruction’ trick 
that is used in for example Plot/Unplot to save 1 extra byte in the rom. These 
are the little nuggets (also the incr/decr trick to find zero more efficiently) 
that make exploring these old super resource constraint systems fun and 
educational.

> On 21 Jun 2020, at 20:53, Ken Pettit  wrote:
> 
> Hi Erik
> 
> This is nice work.  Back in earlier years, I was hoping to get the M100 ROM 
> to a state where it could be re-assembled, but that turned out to be a bit 
> ambitous for me given young kids.

I hear ya. I’ve got two sons myself (12 and 14 years old) and I sure wouldn’t 
have thought of picking up a project like this when they were younger. These 
days we’re happy to see them a few times a day (always outside, at friends or 
in their bedrooms). These days I’ve got to mostly find scraps of time outside 
work, the Gym (well… some weights at home currently), spending weekends with 
the wife and kids, etc. so still pretty constrained… Luckily I don’t watch any 
TV nor do I sleep long so I’ve got some time left to play around…
That said, this project will take plenty of time to finish. I’m willing to go 
pretty fast and allow for some room for error as I can always assemble parts of 
the code and just do a diff with the original segment of rom to know the 
translation is pure.
Going through in a few passes also helps.. I just introduce labels first like 
L: and then replace these with more logical names later. So in time 
the code will look more and more like it was created from scratch instead of 
after the fact I hope.
I’m not in a whole lot of hurry either, its kind of nice to be able to work on 
some things without customer/investor expectations ;)

Erik 

> 
> I have attached a zip file with a more recent M100 ROM disassembly.  I 
> realized I had't uploaded the latest to Club100.  The latested one on Club100 
> Personal libraries is only 761046 bytes, but the most recent one in the zip 
> file is 844833 bytes, so it has quite a few more comments which you don't 
> currently have.
> 
> Ken
> 
> On 6/21/20 10:34 AM, Erik van der Tier wrote:
>> Hi All,
>> 
>> Works progressing nicely on this Rom source code project. I’ve added a 
>> README.md to the repository, which I hopes does justice to all the work that 
>> has been done before to create my starting point.
>> 
>> I’ve also now started working on the new OS Rom source file, which I hope to 
>> get to the point where you can assemble it to a fully identical OS ROM to 
>> the original.
>> The following link shows what the result will look like (based on one of the 
>> first routines that I’ve processed to some detail. My goal is that the 
>> source will not contain any ‘raw’ addresses, so I’m replacing these with 
>> labels, following existing ‘official’ naming where I can find it.
>> 
>> https://github.com/eriktier/RomT102Disassembly/blob/master/OSRROMT102.asm85#L2947
>>  
>> 
>> 
>> Cheers,
>>Erik
>> 
>>> 
>> 
> 
> 

Re: [M100] Annotated disassemble of T102 rom

[Erik van der Tier]

Hi All,

Works progressing nicely on this Rom source code project. I’ve added a 
README.md to the repository, which I hopes does justice to all the work that 
has been done before to create my starting point.

I’ve also now started working on the new OS Rom source file, which I hope to 
get to the point where you can assemble it to a fully identical OS ROM to the 
original.
The following link shows what the result will look like (based on one of the 
first routines that I’ve processed to some detail. My goal is that the source 
will not contain any ‘raw’ addresses, so I’m replacing these with labels, 
following existing ‘official’ naming where I can find it.

https://github.com/eriktier/RomT102Disassembly/blob/master/OSRROMT102.asm85#L2947
 


Cheers,
   Erik

> 

Re: [M100] TPDD Disk?

[Charles Hudson]

Brian,

Thank you for your offer which I gladly accept; let me compensate you for
your expenses.  Please PM me at clh...@gmail.com with details.

Thanks again,

-CH-



Virus-free.
www.avg.com

<#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

Re: [M100] TPDD Disk?

[Brian White]

Ok I would definitely get new boards. That is from even before the "old but
still ok" version I thought you must have had.

I think that one is ok electrically but really that was just my first shot
at importing Steve's original Eagle files into KiCAD.

The problems with it are the silkscreen is obviously all messed up. There
is no good way to provide power to the board for flashing the cpld (I used
an actual socket, you will have jerry rig something with maybe rubber bands
holding wires on the pins 1 & 14 edge connectors). There is no good way to
hold port_en high to flash the cpld. (you have to clip a jumper to the vcc
pin on the jtag and hold the other end manually touching the side of a
resistor, and if you brush the wrong side of that same resistor, you poof
the 3.3v regulator, and operate a laptop while holding that jumper wire in
place...)

I do think it's electrically the same as Steve's original, just with messed
up silk screen. So, you *could* follow the old directions on the wiki to
see where to touch the jumper wire to hold port_en for programming. The
current directions include a link to the old directions. You'll have to
look at the pics to tell which jtag pins are which too I guess. The
arrangement hasn't changed, so an old picture that shows where tdi, tdo,
tck, etc are, it's the same position on yours.

I mean, I would even rather send you a few of my own left over boards than
see you use that board. They are left over. I don't sell REX's or anything
so once I was done testing the updated designs and done building the couple
I need, the rest of the boards are just left over after that, doing nothing.

And I didn't have any carrier at that time so I guess that means you didn't
get any version of a carrier. The original rex and this one was still just
using paperboard and ribbon glued to the bottom.

You could do that original spacer & ribbon, but I think you can actually
get that version into the current carrier which would be better (safer from
mangling your socket pins) than the spacer & ribbon.

The chips and other components are the same, so you could just order the
current boards for $6 and a carrier for another $6, and the rest of the
parts you already have, if you didn't want to take my free left over ones.
I don't know if I have leftovers of the very last version, but several
versions before that were basically the same and would be fine. I think you
would get mine faster too since it would just be the mail, no manufacturing.

-- 
bkw

On Sun, Jun 21, 2020, 8:29 AM Charles Hudson  wrote:

> Brian,
>
> Attached pic shows the REX board I obtained last year.
>
> -CH-
>
>
> 
>  Virus-free.
> www.avg.com
> 
> <#m_-5685505497623102292_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>