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From: ronald@csuchico.UUCP
Newsgroups: comp.sys.m6809
Subject: Re: 16k Coco purchase query
Message-ID: <668@csuchic.csuchico.UUCP>
Date: Mon, 10-Aug-87 06:35:32 EDT
Article-I.D.: csuchic.668
Posted: Mon Aug 10 06:35:32 1987
Date-Received: Wed, 12-Aug-87 06:44:04 EDT
References: <1248@ius2.cs.cmu.edu>
Organization: California State University, Chico
Lines: 44
Summary: Re: 16K CoCo purchase query

In article <1248@ius2.cs.cmu.edu>, ralphw@ius2.cs.cmu.edu (Ralph Hyre) writes:
> Is a 16K Coco (presumably without extended ROM) worth $40 (new)?
> Is there any hope I can add on enough (memory, mainly - probably through
> the expansion connector) to run OS-9 level 2 without exceeding the cost
> of a CoCo 3 system or other OS-9 capable system in the process?

$40?  Sure, if you just wanted to play the ROMPAK games.  OS-9 Level II
requires just too much in the way of specialized memory management
hardware to be cost effective.  You could upgrade to the current CoCo 2
and run OS-9 Level I.

> If I have to buy the extended ROM I'm looking at $39 extra, I have some 64k
> RAM chips lying around, does somebody make an expansion box for the CoCo that
> plugs in and gives a disk interface [I figure I can get bare floppy drives
> and such pretty cheap, as long as I can get the interface from somebody],
> more memory (DAT-compatible 512k?), serial/parallel, etc? 

It would end up costing you as much as the new CoCo 3 ($169 in the new ads
in Rainbow magazine)!

> My memory is fuzzy, can I do machine language from BASIC without the
> extended ROM? (I could live with cassettes and the bit-banger serial port
> for some months if necessary - I'm hoping to make a quick-and-dirty 
> communications processor out of the thing, if I can tie the bit-banger to
> the interrupt line or do hardware handshaking it might work, but I'd rather
> get real hardware.)

Yes.

> If I can get a REAL MULTITASKING system for $200 for hardware (machine+disk)
> and $100 for software I'd be REAL HAPPY.

OS-9 on the Color Computer is not a true multitasking system due to lack of
DMA and the NMI kludge of the disk controller.  Too many interrupts can (and
do) get lost.  I'm hoping the CoCo 4 (if Tandy ever gets off its ass) will
break away from the old CoCo mode and use the real 6809 hardware like the
6829 (with 8 of them you can manage two megabytes of memory, or one meg and
memory protection!), DMA, and maybe even *gulp* multiple processors!

-- 
Ronald Cole				| uucp:     ihnp4!csun!csuchic!ronald
AT&T 3B5 System Administrator		| PhoneNet: ronald@csuchico.edu
@ the #_1_ party school in the nation:	| voice     (916) 895-4635
California State University, Chico	"It's O.K." -Hal Landon Jr., Eraserhead