[Coco] MC6847 ( Motorola DS9823)

[john dumas]

On 3/22/2013 2:40 AM, Stephen H. Fischer wrote:
> Hi,
>
> Only when we can compare the 6847 and the 6847T1.
>
> Another interesting comparison would be the 6845 and the 6847.
No comparison. The 6845 was just in essence just an "address generator".
But had a lot of features to serve as the basis for a really good 
terminal of the day.
[See the app note for a 6809/6845 system by Ed Rupp.]
>
> Then comparing the 684X with the 6545.
>
> Synertek always added features to one up Motorola. Perhaps the 6545 
> was pin compatible with the 6847T1.
Nope. Not even close. Two totally different beasties.

cheers,
johnd
>
> I got SN000001 of the 6809 adapter for the stock 6502 SYM-1. I had to 
> get an EPROM from Halted for Synertek to burn to fix a problem. I got 
> FLEX running after getting replacements for two (2) bad floppy drives. 
> My hand entered boot worked the first time with a drive that had a 
> properly aligned head, it just would not work with either of the two 
> bad drives.
>
> I went over to Synertek trying to get something as soon as I heard 
> they were sold and being shut down.
>
> Everything had to be destroyed! It was a tax write-off.
>
> Just like Haltek was closed down by Oracle (NO NOT that Oracle) for a 
> tax write-off.
>
> Halted is still going strong! www.halted.com/
>
> SHF
>
>
> ----- Original Message ----- From: "Arthur Flexser" <flexser at fiu.edu>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Thursday, March 21, 2013 11:34 PM
> Subject: Re: [Coco] MC6847 ( Motorola DS9823)
>
>
>> Interesting that Bob Rosen said Spectrum Projects was working on an
>> adapter board to allow earlier CoCos to use the 6847T1.  Don't recall
>> such a board ever being advertised by them, so it's likely the project
>> never made it to market.  Would such a project have involved anything
>> more than rerouting a few lines to connect to different pins, similar
>> to the adapter to allow a 28-pin EPROM to be used in a disk controller
>> with a 24-pin ROM socket?  Seems like there'd have been some demand
>> for such an adapter.  A simpler version of Green Mountain Micro's
>> Lowerkit (tip of the hat to Dennis Kitsz), which I had in my CoCo 1.
>>
>> Art
>>
>> On Thu, Mar 21, 2013 at 10:53 PM, Stephen H. Fischer
>> <SFischer1 at mindspring.com> wrote:
>>>
>>> ----- Original Message ----- From: "Bill Pierce" 
>>> <ooogalapasooo at aol.com>
>>> To: <coco at maltedmedia.com>
>>> Sent: Thursday, March 21, 2013 7:24 PM
>>>
>>> Subject: Re: [Coco] MC6847 ( Motorola DS9823)
>>>
>>>
>>>>
>>>> Since the real search is for the datasheet for the MC6847T1,
>>>
>>>
>>> Hi,
>>>
>>> My printed CoCo 2 Service Manual does NOT have the appendix.
>>>
>>> I now have confirmed that I did not find a CoCo 2 Service Manual 
>>> earlier in
>>> the day.
>>>
>>> I think that we did this same exercise a few years (Decades) ago.
>>>
>>> I did find this in the July 1985 Rainbow:
>>>
>>> ---------------------------
>>> . . . BUT WORKING ON IT
>>>
>>> Editor;
>>>
>>> Referring to Gary McConville's letter on
>>> Page 8 in the May 1985 rainbow that claims
>>> the new Motorola VDG chip (the 6847-T1)
>>> is "pin for pin" compatible with the old 6847,
>>> this contradicts the data my company has
>>> received from Motorola. The information
>>> about the 6847-T1 clearly shows it has a
>>> different pin configuration.
>>>
>>> Spectrum Projects is currently investigat-
>>> ing a satellite adapter board to retrofit older
>>> CoCos with the new VDG chip. The main
>>> advantage of this new chip is true lowercase
>>> letters instead of reverse video. Also, the
>>> new 26-3 134B and 26-3 136B CoCo 2s will
>>> fully support the double speed poke.
>>>
>>> Bob Rosen
>>>
>>> President, Spectrum Projects
>>>
>>> Woodhaven, NY
>>>
>>> ---------------------------
>>>
>>> No joy either with the alternate part number.
>>>
>>> SHF
>>>
>
>
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