[Coco] Re: Let me introduce myself (GW/CoCo BASIC similarities)

[farna at att.net]

I have one big programming accomplishment: I wrote a genealogy database program for the CoCo3 way back when. It was great -- I threw every little trick and tweak I could find in there, including POKEing to "double speed" then automatically dropping back for disk I/O and back up again when done. I masked the file names so that they looked like ML files (don't ask me how to do that now!), but a knowledgeable CoCo programmer could easily get around that. But it ran so fast that most people assumed it WAS machine language. 

So what has this got to do with GW-BASIC? What I started to do was port a PD GW-BASIC program over to the CoCo3. I ended up re-writing 85-90% of the code due to differences in the BASICs and a few limitations of the CoCo. The commands are similar, and for really simple programs you can easily port them, but something larger and useful is totally different. All disk I/O had to be re-written -- no ROM calls on the CoCo, disk commands are integrated. Limits on string names, data formats, and the most troublesome -- screen locations. All had to be re-written. Enough that I credited the original program as a guide only (something like "based on xxxx for GW-BASIC"). In the end it was a totally different program that worked in a similar fashion as the GW-BASIC one. 

I will freely admit that I couldn't have done it with disecting the original and totally re-writing it, but it took the better part of a year to do (spare time project), and I spent many full days at it. I too saw the similarities and figured "gee, it should be easy to port a GW-BASIC program to the CoCo, especially the CoCo3" (fewer memory limitations), but it was far from it! I also had the help of a book on porting between different BASICS, which had CoCo2 BASIC included. I had to figure out some of the CoCo3 specific commands. Commodore 64, Apple II, and TRS-80 BASICs were also included, and I think at least one other (I believe there were six BASICs total). Only GW, TRS-80, and CoCo bore many similarities. I'm pretty sure I'd have given up if I'd tried on a Commodore 64 or Apple II. I considered it at several points with the CC3!! 

--
Frank Swygert
Publisher, "American Independent 
Magazine" (AIM)
For all AMC enthusiasts
http://farna.home.att.net/AIM.html
(free download available!)

 -------------- Original message ----------------------

Date: Wed, 1 Feb 2006 12:16:11 -0800 (PST)
From: Russell Flowers <coffeecircle at yahoo.com>
Subject: [Coco] Re: [Color Computer] Re: Let me introduce myself

--- James the Animal Tamer <emucompboy at yahoo.com>
wrote:

> --- In ColorComputer at yahoogroups.com, Diego Barizo
> <diegoba at ...> wrote:
> >
> > Remember that CoCo Basic is 95% compatible with
> QBasic/GWBasic.
> > That means that with just a little rework his
> programs will run and 
> > compile on a PC,
> > Can a Commodore do that ???? ;-) :-P
> 
> In a fair comparison, the Commodore should do just
> as well as the 
> CoCo.  Commodore BASIC is Microsoft version 2 BASIC
> -- the only 
> differences I can think of at the moment is that the
> INKEY$ keyword got 
> replaced with something else, and EXEC got replaced
> with SYS.
> 
> 
I don't know... IIRC, most C64 BASIC listings were
full of "special characters" that you got through
various key combinations. Remember all those graphics
characters on the sides of the keys?