[Coco] Curious DECB File o bytes

Willard Goosey goosey at virgo.sdc.org
Sun Sep 9 03:40:18 EDT 2012


On Sat, Sep 08, 2012 at 11:42:32PM -0400, Luis Fernández wrote:

> Also 32 bytes for directory entry? 16 bytes are used, and 16
> reserved for that?

The other 16 bytes are defined and used by Color TRS-DOS, which is
what Color Disk EDTASM and some other early Tandy apps ran on.

CTRSDOS used, what, 2K to 3K RAM and gave disk BASIC an
assembly-friendly interface to file use, complete with an overlay
engine.  But 3K on top of BASIC's memory footprint was just too much.

TRSDOS could get away with that trick on a Model III, which only had 16K
ROM. On a 32K ROM machine it's a disaster. 

Also, CTRSDOS couldn't be distributed freely, so if you wrote a
program that used it you could only distribute a full, working version
through Tandy.  Disk EDTASM was an expensive package.  Who's going to
buy your $20 game if they need a $100 assembler to run it?

It also had a stupid menu system for a shell that broke its own rules
by writing directly to the text screen. 

So of course nobody used it.

Willard
-- 
Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
I search my heart and find Cimmeria, land of Darkness and the Night.
  -- R.E. Howard



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