TRS-80 to Microbee Conversion?

[CheshireNoir]

Hey Folks,
How much effort is involved in porting games from the TRS-80 to the Microbee? I know there are quite a few games that have been ported across already.
(This seems like it would be the wheelhouse of @someone from past posts)

I only ask as I recently saw a demo of Thirteen Ghosts for the TRS-80 and it struck me that it'd make an excellent game to target for our beloved 'bee.

Any comments welcomed!

John

[RedskullDC]

Hi John,

Not too difficult to be honest.

You may need to re-locate the TRS-80 exe code, as most disk loadable games begin above $5200.
Screen accesses will need to be patched TRS-80 ($3C00-$3FFF) => HiMEM on Bee.

You'll need to write routines to pre-load the programmable GFx chars on the Bee with TRS-80 Gfx.

You'll need some routines which take Bee Keypresses, and simulate press/release in the TRS-80 keyboard area ($3800-$3880) (iirc).

Take a look at the BIG-5 conversions downloadable from here. (Galaxy Invasion, Cosmic Fighter etc.)
Most of that work will already be done for you.

I did a few Exidy Sorcerer conversions a few years ago, which is a very similar process.

Cheers,
Leslie

[CheshireNoir]

Thanks Leslie!

Don't know how long this'll take, but I guess I've got a project :-D

John

[ChickenMan]

I've converted quite a few of the DUBOIS AND MCNAMARA TRS-80 games to the run on the 'bee some years back. These are the steps I took -

1. Change ORG to 900h
2. Call 8027h (LORES) that sets up the TRS-80 graphics
3. Change all reference to TRS-80 screen mem ((3C00h-3FFFh) to F000h to F3FFh.
4. Change their SOUND code to suit the Microbee
5. Add a code routine to look for a key press and then change the code to use that routine.  This is the hardest part I find.

Have a read of the porting_meteor_mission_2_to_microbee.pdf file by Brad Robinson.  Its in the Microbee/Documentation/Articles folder in the Repository as it explains the whole process in detail.

[someone]

Don't forget to make allowances for self modifying code.

[CheshireNoir]

@someone that's amazing!

John

[ChickenMan]

I had a look across the net and cant seem to find it, thought I'd try it on my System 80

[CheshireNoir]

Funny you should mention the System 80...
I picked up an untested blue label System 80 this morning!

John

[RedskullDC]

I had a look across the net and cant seem to find it, thought I'd try it on my System 80

Check out: https://willus.com/trs80/

Near the top of the page, items #5,6,7,8

Cheers,
Leslie

[ChickenMan]

Arr, thanks Leslie, I was searching for Thirteen Ghosts not 13 Ghosts Soon discovered I already have it in my TRS-80 file collection