3 Dec
2024
3 Dec
'24
12:35 p.m.
They seem to have upgraded the video output!
I found the picture on the front page of this web site
humorous. It's a
place that sells old Jeep parts. Note the computer surfing the web.
https://www.kaiserwillys.com/
4 Dec
4 Dec
8:46 a.m.
On Tue, Dec 3, 2024 at 8:42 PM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
They seem to have upgraded the video output!
Is it a CoCo or the Videotex terminal?
The latter was never sold in the UK for obvious reasons, but looking
at the service manual for it, it does seem to have the same video
circuitry as the CoCo.
> I found the picture on the front page of this web site humorous. It's a
> place that sells old Jeep parts. Note the computer surfing the web.
> https://www.kaiserwillys.com/
-tony
8:50 a.m.
What is not well known is that the CoCo was actually designed by
Motorola, and appeared in their Microprocessor data book as a
double-page schematic to promote the 6809!
cheers,
Nigel
On 2024-12-04 11:46, Tony Duell via cctalk wrote:
On Tue, Dec 3, 2024 at 8:42 PM Fred Cisin via cctalk
<cctalk(a)classiccmp.org> wrote:
--
Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype: TILBURY2591
They seem to have upgraded the video output!
Is it a CoCo or the Videotex terminal?
The latter was never sold in the UK for obvious reasons, but looking
at the service manual for it, it does seem to have the same video
circuitry as the CoCo.
> I found the picture on the front page of this web site humorous. It's a
> place that sells old Jeep parts. Note the computer surfing the web.
> https://www.kaiserwillys.com/
-tony
8:55 a.m.
On Wed, Dec 4, 2024 at 4:50 PM Nigel Johnson Ham via cctalk
<cctalk(a)classiccmp.org> wrote:
What is not well known is that the CoCo was actually designed by
Motorola, and appeared in their Microprocessor data book as a
double-page schematic to promote the 6809!
Wasn't it actually a suggested schematic for the 6883 synchronous
address multiplexer chip?
-tony
9:46 a.m.
The story I heard is that Motorola went to Tandy asking them to use
their 6809 chip.
Tandy said, ok, you design a system for us with a cost of $xxx and we
will sell it.
Motorola then designed the color computer using the 6883 SAM chip which
handled almost all of the glue logic for the system. This includes
address decoding, DRAM refresh, system clock, etc.
The CoCo was made up of 3 main chips:
* 6809E CPU (The E used a 2 phase clock so they could alternate cycle
main RAM and video RAM)
* 6883 Synchronous Address Mutiplexor (took care of all of the glue logic)
* 6845 Graphics Controller Chip
Add RAM and a few Misc. chips and discretes and you have a CoCo!
Great machine but no one at Tandy realized the power of the 6809. Maybe
the CoCo III came close to exploiting all that the 6809 could do.
On 12/4/2024 10:55 AM, Tony Duell via cctalk wrote:
On Wed, Dec 4, 2024 at 4:50 PM Nigel Johnson Ham via
cctalk
<cctalk(a)classiccmp.org> wrote:
What is not well known is that the CoCo was
actually designed by
Motorola, and appeared in their Microprocessor data book as a
double-page schematic to promote the 6809!
Wasn't it actually a suggested schematic for the 6883 synchronous
address multiplexer chip?
-tony
9:51 a.m.
On Wed, Dec 4, 2024 at 5:46 PM Mike Katz <bitwiz(a)12bitsbest.com> wrote:
The story I heard is that Motorola went to Tandy asking them to use their 6809 chip.
Tandy said, ok, you design a system for us with a cost of $xxx and we will sell it.
Motorola then designed the color computer using the 6883 SAM chip which handled almost
all of the glue logic for the system. This includes address decoding, DRAM refresh,
system clock, etc.
The CoCo was made up of 3 main chips:
6809E CPU (The E used a 2 phase clock so they could alternate cycle main RAM and video
RAM)
6883 Synchronous Address Mutiplexor (took care of all of the glue logic)
6845 Graphics Controller Chip
Actually a 6847 which is a rather different device
Add RAM and a few Misc. chips and discretes and you have a CoCo!
True.
The schematic in the datasheet I pointed to also shows the ROMs and a
pair of 6821 PIAs as in the CoCo.
Great machine but no one at Tandy realized the power of the 6809. Maybe the CoCo III
came close to exploiting all that the 6809 could do.
Tandy did sell Microware OS-9, BASIC-09. Pascal and C for the CoCo.
That was a rather nice mutliuser OS. I remember at the tme I was
runing OS-9 (initially leval 1 on a 64K CoCo 2, then level 2 on a 512K
CoCo 3) and had to use MS-DOS on a computer at a company I was doing
some work for. The latter felt so primitve by comparison.
-tony
9:53 a.m.
On Wed, Dec 4, 2024 at 5:51 PM Tony Duell <ard.p850ug1(a)gmail.com> wrote:
The schematic in the datasheet I pointed to also shows
the ROMs and a
pair of 6821 PIAs as in the CoCo.
Sorry that never went to the list. The datasheet I refer to is here :
https://archive.org/details/Motorola_MC6883_Synchronous_Address_Multiplexer…
-tony
9:58 a.m.
You are correct. The 6845 was monochrome and the 6847 was the color chip.
If you count a maximum of 16 colors as a color chip🙂. 4 Colors with
artifacting in the highest resolution mode.
On 12/4/2024 11:51 AM, Tony Duell wrote:
On Wed, Dec 4, 2024 at 5:46 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
The story I heard is that Motorola went to Tandy
asking them to use their 6809 chip.
Tandy said, ok, you design a system for us with a cost of $xxx and we will sell it.
Motorola then designed the color computer using the 6883 SAM chip which handled almost
all of the glue logic for the system. This includes address decoding, DRAM refresh,
system clock, etc.
The CoCo was made up of 3 main chips:
6809E CPU (The E used a 2 phase clock so they could alternate cycle main RAM and video
RAM)
6883 Synchronous Address Mutiplexor (took care of all of the glue logic)
6845 Graphics Controller Chip
Actually a 6847 which is a rather different device
Add RAM and a few Misc. chips and discretes and
you have a CoCo!
True.
The schematic in the datasheet I pointed to also shows the ROMs and a
pair of 6821 PIAs as in the CoCo.
Great machine but no one at Tandy realized the
power of the 6809. Maybe the CoCo III came close to exploiting all that the 6809 could
do.
Tandy did sell Microware OS-9, BASIC-09. Pascal and C for the CoCo.
That was a rather nice mutliuser OS. I remember at the tme I was
runing OS-9 (initially leval 1 on a 64K CoCo 2, then level 2 on a 512K
CoCo 3) and had to use MS-DOS on a computer at a company I was doing
some work for. The latter felt so primitve by comparison.
-tony
10:13 a.m.
On Wed, Dec 4, 2024 at 5:58 PM Mike Katz <bitwiz(a)12bitsbest.com> wrote:
You are correct. The 6845 was monochrome and the 6847 was the color chip.
The 6845 was called the 'CRT Controller'. It was basically a set of
programmable counters that would address the video RAM, generate sync
signals, latch the address if a lightpen detected a 'hit' and so on.
It did not do anything with the data from the video RAM, that was
handled by other circuitry. It could certainly be used in colour
systems, the BBC micro, IBM CGA card and so on.
The 6847 was the the video display generator. It could generate the
video addresses and timing (e.g. the Acorn Atom) but didn't have to.
It did handle the data from the video RAM, it had an internal
upper-case only character generator, block graphics, etc. It did
generate colour video.
-tony
10:24 a.m.
Tony,
Thank you for the education. I did some minimal programming of the 6847
on the CoCo and nothing really on the 6845.
A majority of the 6809 programming that I did was for Gimix, when I
worked there in the early 1980's.
And then on embedded 6809 based system, also in the early 1980's.
Mike
On 12/4/2024 12:13 PM, Tony Duell wrote:
On Wed, Dec 4, 2024 at 5:58 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
You are correct. The 6845 was monochrome and the
6847 was the color chip.
The 6845 was called the 'CRT Controller'. It was
basically a set of
programmable counters that would address the video RAM, generate sync
signals, latch the address if a lightpen detected a 'hit' and so on.
It did not do anything with the data from the video RAM, that was
handled by other circuitry. It could certainly be used in colour
systems, the BBC micro, IBM CGA card and so on.
The 6847 was the the video display generator. It could generate the
video addresses and timing (e.g. the Acorn Atom) but didn't have to.
It did handle the data from the video RAM, it had an internal
upper-case only character generator, block graphics, etc. It did
generate colour video.
-tony
10:30 a.m.
On Wed, Dec 4, 2024 at 6:24 PM Mike Katz <bitwiz(a)12bitsbest.com> wrote:
Tony,
Thank you for the education. I did some minimal programming of the 6847
on the CoCo and nothing really on the 6845.
A majority of the 6809 programming that I did was for Gimix, when I
worked there in the early 1980's.
And then on embedded 6809 based system, also in the early 1980's.
In the second half of the 1980s I did a few embedded 6809 projects, my
final year project at university and then some designs a for a company
I did a summer job for. I developped all the code on my CoCo system
under OS-9 and burnt the binaries into EPROMs using a home-made
programmer on the CoCo.
I still have all the hardware, still all works. My Motorola databook
is still on the shelf, although the pages are falling out due to all
the use it has had. Still love the 6809.
-tony
10:49 a.m.
Tony,
I still say the 6809 was the best 8 bit micro ever.
Though I don't have any 6809 systems here I still have my 6809/6809E
Microprocessor Programming Manual from 1981.
Lately I do more with my PDP-8's then anything recent like the 6809🙂
On 12/4/2024 12:30 PM, Tony Duell wrote:
On Wed, Dec 4, 2024 at 6:24 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
Tony,
Thank you for the education. I did some minimal programming of the 6847
on the CoCo and nothing really on the 6845.
A majority of the 6809 programming that I did was for Gimix, when I
worked there in the early 1980's.
And then on embedded 6809 based system, also in the early 1980's.
In the
second half of the 1980s I did a few embedded 6809 projects, my
final year project at university and then some designs a for a company
I did a summer job for. I developped all the code on my CoCo system
under OS-9 and burnt the binaries into EPROMs using a home-made
programmer on the CoCo.
I still have all the hardware, still all works. My Motorola databook
is still on the shelf, although the pages are falling out due to all
the use it has had. Still love the 6809.
-tony
10:53 a.m.
On Wed, Dec 4, 2024 at 6:49 PM Mike Katz <bitwiz(a)12bitsbest.com> wrote:
Tony,
I still say the 6809 was the best 8 bit micro ever.
No dispute from me on that point :-)
Though I don't have any 6809 systems here I still have my 6809/6809E
Microprocessor Programming Manual from 1981.
I still have my CoCos and a Acorn System with a 6809 CPU board in it.
And of course plenty of them in embedded systems -- mosr HP disk or
tape units contain one. So does my HP1630 logic analyser.
Lately I do more with my PDP-8's then anything recent like the 6809🙂
Another elegant processor design.
-tony
11 a.m.
I remember trying to hack the HP9114 3.5" HP-IL floppy drive to handle
two drives in a single enclosure back in the day.
On 12/4/2024 12:53 PM, Tony Duell wrote:
On Wed, Dec 4, 2024 at 6:49 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
Tony,
I still say the 6809 was the best 8 bit micro ever.
No dispute from me on that
point :-)
Though I don't have any 6809 systems here I
still have my 6809/6809E
Microprocessor Programming Manual from 1981.
I still have my CoCos and a Acorn
System with a 6809 CPU board in it.
And of course plenty of them in embedded systems -- mosr HP disk or
tape units contain one. So does my HP1630 logic analyser.
Lately I do more with my PDP-8's then
anything recent like the 6809🙂
Another elegant processor design.
-tony
11:06 a.m.
On 2024-12-04 13:49, Mike Katz via cctalk wrote:
Tony,
I still say the 6809 was the best 8 bit micro ever.
Though I don't have any 6809 systems here I still have my 6809/6809E
Microprocessor Programming Manual from 1981.
Lately I do more with my PDP-8's then anything recent like the 6809🙂
On 12/4/2024 12:30 PM, Tony Duell wrote:
I agree. The user stack pointer was a killer feature. Our repeater
controller controlled, in real time, a 16 x 16 crosspoint matrix
connecting audio and keying from receivers to transmitters, timeout
timers for all RF gear individually, DTMF decode, and separate morse
callsign generation for each transmitter. It could decode on one
channel while it was executing a DTMF command on another. We originally
tried to do his with a 6800 but we needed one more 16-bit register to
achieve real time and the morse sounded like it was being sent by a
duink sailor with his left foot.!
I heard they only discontinued it because the factory burned down, and
never came up with its replacement.
cheers,
Nigel
--
Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype: TILBURY2591
On Wed, Dec 4, 2024 at 6:24 PM Mike Katz
<bitwiz(a)12bitsbest.com> wrote:
Tony,
Thank you for the education. I did some minimal programming of the
6847
on the CoCo and nothing really on the 6845.
A majority of the 6809 programming that I did was for Gimix, when I
worked there in the early 1980's.
And then on embedded 6809 based system, also in the early 1980's.
In the second half of the 1980s I did a few embedded 6809 projects, my
final year project at university and then some designs a for a company
I did a summer job for. I developped all the code on my CoCo system
under OS-9 and burnt the binaries into EPROMs using a home-made
programmer on the CoCo.
I still have all the hardware, still all works. My Motorola databook
is still on the shelf, although the pages are falling out due to all
the use it has had. Still love the 6809.
-tony
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days inactive
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14 comments
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participants (4)
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Fred Cisin -
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Tony Duell