A Bill Rose
Conversation
by Geoff Oltmans
> -----Original
Message-----
> From: Geoff Oltmans
> Sent: Friday, March
12, 2010 5:11 PM
> To:
> Subject: Greetings!
Hello Mr. Rose:
Believe it or not, I
stumbled across your name while perusing some source code that you
helped write for the Coleco ADAM Master 6801! I just wanted to give you some kudos for
helping to create one of my favorite home computers. This machine
more than any other shaped my interest in computing technology as a child.
I now work in embedded
system design at a company called ADTRAN. We design
telecommunications equipment. In my spare time I like to dissect your
work on the ADAM, and have been
porting Marcel de Kogel's excellent ADAM emulator to work in Mac OS
X.
I just felt it necessary
to write to you and tell you how much I have personally enjoyed using
the ADAM these many years. :)
Geoff
> From: Bill Rose
> To: Geoff Oltmans
> Sent: Mon, March 15,
2010 1:14:51 PM
> Subject: RE:
Greetings!
Hi Geoff
Wow that's a blast from
the past. Didn't know anyone outside of a few at Coleco knew I wrote
code for the Adam. I actually designed much of the hardware. My code was
primarily the drivers specific to my hardware design. It had to be
written in assembler to operate efficiently. The hardware had some very specific
requirements that few of the software team were able to fully
understand to write the code. Very timing specific to handle the DMA without impacting the
Z80's operation. In fact they tried to rewrite it but ended up going
back to my original code. Long story there.
Nice to know someone
remembers the Adam. It was pretty revolutionary at the time. Its
undoing was trying to go from initial schematics to shipment in 4 months. Took us about 8
months to get it stable but by then it was too late. The early
shipments were too buggy to survive the bad reviews. Very long story there.
I still have mine though
it is in storage at this point. I also have some game screens in
EPROM for Zaxon and others that were never released.
Bill
> From: geoffrey
oltmans
> Sent: Monday, March
15, 2010 2:46 PM
> To: Bill Rose
> Subject: Re:
Greetings!
Bill:
I actually started
disassembling the code from dumps I made from the actual MCUs, but
ended up getting a set of the source code for several of the 6801 MCUs from another fellow
ADAM tinkerer on the Coleco ADAM mailing list. These were all
listings from the ADAM Technical Manual apparently. The combination of the MIOC/6801 and
ADAMNet implementation are probably the most interesting aspect of
the system to me. That and the tape drive implementation, which seemed like a novel
solution to the relatively high price of disk based storage of the
time. It probably didn't hurt that it played Coleco Vision games
which I also loved at the time. ;)
Anyway, I've never seen any other home computers from the time frame
that had a serial communications channel for the expansion devices that was DMA'able. I also
like that it was generic enough to support a wide variety of
different devices. I have kicked around the idea of making a
USB->ADAMNet adapter so that you could
use real ADAM peripherals with the emulator on a PC, or alternatively
use a PC to emulate peripherals on a real ADAM system since they are relatively
scarce. Probably would use something like a Coldfire microcontroller
maybe (since I've got a neat little SBC prototyping board from
Freescale anyways), or dirt cheap
like a PIC. I'm new to the world of USB, so I figured that might be a
novel idea for a learning tool. Did you also write bits of the EOS
code also?
It is a shame that the
system couldn't overcome the initial bad reviews. Bad news travels
faster than good news unfortunately, and I guess they were so
concerned about missing out on the
Christmas buying season that slipping the ship date was politically
impossible.
I think I may have seen a
dump of a demo cartridge (store demo maybe?) for the ADAM that showed
off a lot of different software they had planned. Might be the same thing you're talking
about. Couple quick questions for you... I have seen a picture of
alternate ADAM console pictures from the CES prior to release. It
looked like it had slot-loading DDP
drives similar to a car cassette player. Does this sound familiar?
Also, is it true that the ADAM started out life as the Super Game
Module attachment for the Coleco
Vision, and then morphed into the computer design, or were they
completely separate designs?
Nice to be able to put a
(virtual) face to a design like this. :)
Later!
Geoff
> From: Bill Rose
> To: geoffrey oltmans
> Sent: Mon, March 15,
2010 2:41:41 PM
> Subject: RE:
Greetings!
The serial network was my
work. The original used the Z80 to 'bit bash' RS232 ports to each
peripheral. I did a quick calc and found there were no where near enough
instruction cycles in the Z80 to also run the OS and word processor.
I designed the DMA at home in my 'free time'. We switched to the new design in early
May but management insisted we had to ship in Aug. There was no
hardware, drivers, or software when we switched. i.e. 4 months to do it all.
Obviously not possible. At one point mgmt asked why we weren't
shipping (around October). The answer was "they are all failing
fina test". Mgmt then
informed manuf to cease final test and ship!!! Bad decision.
The game screens I
referred to were in development when we announced we were exiting
Colecovision as well as others we developed for distribution using the Adam's tape
drives. I ran game design as well as hardware and software
development at that time so I got early releases. These are screens
that have never been seen by
the public. Actually I haven't looked at them in years.
As for your questions,
Adam was supposed to use miniature endless loop tapes - much smaller
versions of the 8 track tapes of the 70's. Problem was reliability. They jammed
just like their larger cousins. We could never get them to operate
for any length of time. We scrapped them for the cassette tape drives. These were similar
to standard cassettes except we added some holes that were used to
align them and hold them in alignment during high speed operation. We operated at
20 ips (inches per second) with FFD/RWD at 80 ips. Standard cassettes
had too much movement to keep the tape in comtact with the head. We also had
to use higher quality tape - basically "first run" tape to
minimize defects in the magnetic media. First run means the first
batch of tape coming off a line.
The bath they use to coat tape degrades as it is used. Similar to
high quality video tape.
The expansion module was
actually a nearly complete Atari game system. About all we used from
Colecovision was the power supply and perhaps the video modulator (I forget
the details). It gave us full compatibility with Atari games because
it was an Atari system. I don't think the Z80 or graphics processor was used for anything when
using the module. Adam was a completely separate effort. No relation
at all. It was the time of the Timex/Sinclair, TRS80 (pronounced Trash 80),
Commodore VIC-20, and Commodore 64. Home computers were getting big
and Coleco wanted to be a player. The initial design was simply a Colecovision with
the RS232 ports added, the endless loop tape drive, a printer, and
keyboard. The idea was that it was a computer with a real operating system and word processor out of the box. No need to program in Basic. I was hired to
work on that design. See above for where it went.
We did design (paper only)
an ASIC that would allow the Z80 to emulate an IBM PC. The designer,
a kid fresh out of college, was Steve Perlman who later went on to found WebTV and
MOXI. We killed the project before implementing it.
As I said, lots of
unwritten history here.
Bill
> From: geoffrey
oltmans
> Sent: Monday, March
15, 2010 4:01 PM
> To: Bill Rose
> Subject: Re:
Greetings!
I think you're referring
to the Expansion Module #1 (Atari 2600 compatible) that was actually
released. It was as you indicate practically a standalone system other
than using the RF modulator and the power supply from the Coleco
Vision. I was referring instead to this gadget (great pictures here,
overlook the inflammatory language about the ADAM <g>). It used
presumably the same wafertape/floopy drive you're talking about with the
original ADAM drives...
http://www.colecovision.dk/sgm.htm
I see they also have a
picture there of Super Zaxxon in CED videodisc form. I had found an
article about Coleco making a videodisc capable system, so there was some
early confusion among the hobbyists about whether it would be
videodisc or wafertape based. I guess they tried both?
Very interesting info
about the IBM PC compatibility mode! I can see how that would have
been in the works. Seems like everyone up to and including the Amiga tried
to make a hardware option for that if they couldn't do it in
software.
I love a good story...
I'll bet the home computer/PC industry was interesting to work in
(and probably somewhat stressful at times) back when it was still
hot.
Geoff
> From: "Bill
Rose"
> Date: March 15, 2010
4:44:23 PM CDT
> To: "'geoffrey
oltmans'"
> Subject: RE:
Greetings!
>
Oh that one!! Another
great story. The microwafer drive was the endless loop I mentioned.
Didn't work. The Supergame Module was supposed to be based
on that but as CES neared we realized it couldn't cut it. The unit
that went to CES had to use ROM'd games "under the
covers". The tapes only held the ROM bank select number repeated
over and over. We would simply read the ROM bank code off the
tapes, delay starting the game for a period of time and then play it
from ROM. Had some quirks too. If someone removed the tape
during play and put in another tape, the old game continued to play
unless they hit reset. Some uncomfortable moments in
front of press as the demonstrator screwed up. The rest is history.
As for the "Super" games, we released some of them on
Adam tapes for play on the Adam. I still have Super Zaxxon and others
though I doubt they still play - the tape drives were a bit
"finiky' even then. I know one of our old techs who still has
copies of almost everything we ever developed.
We did release a floppy
drive for the Adam toward the end but too late to save it. Also too
expensive.
We did work on an optical
disk game system but the games were very poor. The problem was the
disks were really video disks so the games attempted to use
branching based on the player's moves. Do something and branch to
another video scene, do something else, branch again. Seel
times were slow so you had to wait a few seconds to see the next
branch. The video processing at the time was too limited to
seemlessly add game play or over lay the video. Also they were not
good as data disks (no real data format) so loading data took some
work. Killed that one too.
What no one knows is that
we also developed an Apple II knock off in 3 chips. However,
following on the heels of Adam, the banks wouldn't loan the money to
go into production even though we did complete the design, ASICs,
built prototypes and had negotiated with JVC to build it. It
was a land mark machine. It used the Windows concept before the MAC
was out (no one knew to call them
Windows and we never
patented the idea) - drop down menus, etc. It also included a 2400
baud dial up modem and a phone. We could play head to head
games over the phone lines, download/upload files (even unattended
over night), etc. Pick up the phone, your contact list would
pop up - in the middle of a game!! Make the call by pushing a button
or dialing and then resume the game.
Touch the calculator
keypad and a calc would pop up on the screen, etc. The case was
designed by Porsch. Very cool and way ahead of its time. We had
working models - don't know what happened to them.
Also developed a next gen
video game system - 32 sprites per line (Colecovision had 4), much
better graphics, colors, and sound.
But the real kicker were
the 4 vector engines that used the graphics engine for background
graphics. The vector graphics created the space ships, etc. on the
full graphics background. I believe we could handle 2K vectors at 30
frames per second. And with the integral dial up modem, we could
play real-time head to head games with multiple players over phone
lines since each player would put up his own background graphics
and simply send the vector information (very compact) over the phone.
Unfortunately Coleco exited the video game market before we
could launch it. But we did have working prototypes.
They were exciting times.
I ran Advanced R&D and had a team that eventually broke up and
went to Sun, Apollo, Apple, Intel, and others.
Very talented team. We did
some Artificial Intelligence work as well for products like the
Talking Cabbage Patch Dolls (each doll had a digital RF network to let
them coordinate their scripts - they talked to each other, sang songs
together, etc. Another Coleco first was Laser Tag which was
eventually released by Worlds of Wonder.
Bill
-END-
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