A few things:
--
I believe backpack allows you to put any loader you want on the sd card.
I don't know the exact mechanism, but for example a similar project I
have https://github.com/bkw777/PDDuino
lets you bootstrap anything you want by just saving it to a special file
name on the sd card.
You get any of the loader files from here
https://github.com/bkw777/dlplus/tree/master/clients
in your case, anything named *.200, specifically:
https://github.com/bkw777/dlplus/raw/master/clients/teeny/TEENY.200
And just save it to the sd card as LOADER.DO
and then PDDuino will use that file for bootstrap.
I think backpack has a fancier bootstrap process with an initial stage
that autodetects if the attached client is a 100 or 200 the same way a
real TPDD2 utility disk does, but otherwise a similar idea where the
device comes pre-loaded with a ts-dos loader, but it's just the default
not permanent and you can replace it.
--
Simply using TEENY in place of TS-DOS will get you from 6k down to 1.5k,
but you can go further by getting tricky with how you install and invoke
TEENY. The TEENY docs go into some detail about it but the gist is you
get the TEENY code installed into high memory, and then delete the .CO
file and replace it with a smaller trigger file. If you get this right,
then TEENY only consumes about 750 bytes. It's more delicate. If you run
any other .CO program that overwites the high memory area, that wipes
out TEENY, and then you no longer have the .CO file to reinstall from,
so you have to load from serial again. Which, with a backpack is not
much of a chore, especially if you customize the loader.do a little to
make it do a high-ram-trigger-file install instead of saving a .CO file.
I find the original teeny doc hard to follow but one thing it does is
cover all points, except, maybe not, I think there is model 100-specific
basic code in there in the trigger file section.
https://bitchin100.com/wiki/index.php?title=TEENY.CO_MANUAL#Trigger_File_Creation
--
This claims to copy files from bank to bank on 200:
https://bitchin100.com/wiki/index.php?title=Tandy_200_RAM
--
bkw
On 8/10/23 17:21, CopyP wrote:
Hi all,
I have just received a Tandy 200 to go with my 100 and 102. It seems
functional, but leaves me with an odd question:
I have one of Birt’s Backpack drives, which works perfectly with my 100 and
102, using the TS-DOS loader included on the SD card, and referenced in the
Backpack manual. Unfortunately, I don’t have an option ROM with TS-DOS, so I
loose 6K or RAM. On the 100/102 that isn’t too bad, but on the 200, it leaves
insufficient RAM for the documents I am producing.
So, I thought, why not load TS-DOS into one RAM bank, and the documents in
another? Except that I don’t see where TS-DOS can load a file, while it’s
running from (say) Bank #2 on the 200, and save the file in Bank #1. Or, save a
file from Bank #1 to the Backpack, while it’s running from Bank #2.
Is this even possible, or do I need a TS-DOS option ROM? I do have a REX#, but
it doesn’t seem to be functional in the 200. I was hoping to get one of Birt’s
Dial-A-ROMS, but they don’t seem to be available at present.
Any ideas?
Thanks,
Andy
--
bkw
