Coco 2 questions
David Williams
I have a Coco 2 and I'm trying to determine how much memory is in it.
Any suggestions on how to find out? BASIC commands, id the chips for
me, etc. And memory expansion options if it only has 16k as I suspect.
Also, I'm interested in picking up disk drives, tape drives, cables,
software, whatever for it. Currently I have the computer and a serial
cable which won't connect to any serial device I currently have.
Thanks.
-----
David Williams
d...@neosoft.com
http://www.neosoft.com/~dlw
Rogelio Perea H
David Williams wrote:
>
> I have a Coco 2 and I'm trying to determine how much memory is in it.
> Any suggestions on how to find out? BASIC commands, id the chips for
> me, etc. And memory expansion options if it only has 16k as I suspect.
>
David,
You can try also posting at bit.listserv.coco for more CoCo specific
support.
As to how to find the amount of RAM installed in your CoCo try the
following. Hook up the computer to a TV, you won't need anything else
like drives or other peripherals to check the computer out.
Power up and type (after getting the OK prompt):
PRINT MEM [ENTER]
and you should get a report on how much memory the CoCo has. If you get
a figure lower than 10000 (is is more like 8k or so) your CoCo has
16kRAM installed, If you get something around 22384 or so your CoCo has
at least 32k Ram installed. The figures returned are such because the
Basic allocates some space for its graphics screen. On boot up the
reserved space amounts to 4 pages which can be re-established using the
PMODE and PCLEAR commands.
The CoCo Basic was written by Microsoft, yes, Mr Bill Gates managed to
fiddle around with the ROMs before getting the thing ported as GWBASIC
to the Intel based MSDOS systems. So, Basic progrtams between the two
platforms are pretty much portable mind a few changes here and there.
This RSDOS (Radio Shack DOS as CoCo users know it) allocates only 32k
RAM for its environment regardless of the machine having up to its 64k
directly addressable memory installed. So you will get the SAME PRINT
MEM result if your CoCo has 32k or 64k or, lets say it, 128k.
Which catalog number does your CoCo have?. It would help a lot when
asking for support around these forums :-)
Keep in touch.
--
Rogelio Perea / rog...@internogo.com
Bill Yakowenko
In article <325959...@internogo.com>,
Rogelio Perea H <rog...@internogo.com> wrote:
>David Williams wrote:
>> I have a Coco 2 and I'm trying to determine how much memory is in it.
>> Any suggestions on how to find out? BASIC commands, id the chips for
>> me, etc. And memory expansion options if it only has 16k as I suspect.
>
>David,
>
>
>The CoCo Basic was written by Microsoft, yes, Mr Bill Gates managed to
>fiddle around with the ROMs before getting the thing ported as GWBASIC
>to the Intel based MSDOS systems. So, Basic progrtams between the two
>platforms are pretty much portable mind a few changes here and there.
>This RSDOS (Radio Shack DOS as CoCo users know it) allocates only 32k
>RAM for its environment regardless of the machine having up to its 64k
>directly addressable memory installed. So you will get the SAME PRINT
>MEM result if your CoCo has 32k or 64k or, lets say it, 128k.
Not to defend the Evil Overlord or anything, but...
Actually, the reason that CoCo 1+2 BASIC uses only 32K of RAM is that
the processor address space is only 64K. So even if you have 64K RAM,
getting at all of it involves mapping out the BASIC ROMs. That is,
the upper 32K of the address space can be either RAM or ROM. If you
want all 64K RAM, you lose the BASIC ROMs. (Of course, you could copy
the BASIC ROMs into RAM and then map out the ROMs, but you still don't
get to use that RAM for your own nefarious purposes if it is inhabited
by the BASIC interpreter.)
And CoCo 2's couldn't even think about using 128K RAM without *severe*
modifications. Maybe you're recalling CoCo 3's. Other people could
tell you more than I about those things.
Does anyone know for sure if that other Bill (aside from me, of course!)
really left his fingerprints in the CoCo ROMs? I seem to remember
reading that it was actually written by a couple of Japanese programmers
under contract for MicroSloth.
>Which catalog number does your CoCo have?. It would help a lot when
>asking for support around these forums :-)
Do you have a canonical list handy of CoCo catalog numbers and what
they mean? Wanna post it?
>
>Keep in touch.
>--
>Rogelio Perea / rog...@internogo.com
Cheers,
Bill.
PS. In case anyone cares, I maintain a humble CoCo web page (mostly
for CoCo 1's and 2's) at http://www.cs.unc.edu/~yakowenk/coco.html .
I don't put much effort into it these days, but it seems to be
surviving okay without me. :-)
--
--
Bill Yakowenko http://www.cs.unc.edu/~yakowenk yako...@cs.unc.edu
~{SH?KND~} "Too much reality can kill you."
Rogelio Perea H
Bill Yakowenko wrote:
> And CoCo 2's couldn't even think about using 128K RAM without *severe*
> modifications. Maybe you're recalling CoCo 3's. Other people could
> tell you more than I about those things.
Well, in the better days of the CoCo 2 (circa 1984-85) there was a lot
of hoopla for the 128k RAM expansion kits. They were, in one word,
available. No vapor-ware whatsoever. The things worked doing some bank
switching much like the in-famous ROM-RAM techniques implemented to map
out the ROMs and switch in the extra 32k RAM.... Why did they fade into
obscurity?. For one thing, the CoCo 3 came out with its built-in memory
management hardware, and the 128k expansion makers just kept the how's
and why's of their hardware to themselves, shutting the door to a lot of
potential developers those days.
> Does anyone know for sure if that other Bill (aside from me, of course!)
> really left his fingerprints in the CoCo ROMs? I seem to remember
> reading that it was actually written by a couple of Japanese programmers
> under contract for MicroSloth.
Mr Bill Gates himself said in an interview that there would be a
discussion about the insides of the CoCo ROMs. Sometime ago I was at one
used computer stuff store and was reading an old book about computers.
There came the C64, the early IBM PC and of course the CoCo. The book
stated, and I quote "...some people refer to the Tandy Color Computer as
a quite not right IBM PC...", and this was within a paragraph that
discussed the similarities between the CoCo's Basic and the IBM PC's
GWBASIC.
I do not know about any subcontract Microsoft might had landed for
writing the CoCo's Basic. The CoCo 1 did came on long before (as far as
time for computers goes) the IBM PC, and the very first Basic for the
later literally sucked (remember BASIC.COM?) when compared to the CoCo's
Extended Color Basic. Then came BASICA and of course, Microsoft's Gee
Whizz Basic....