[Coco] MC6847 ( Motorola DS9823)

[Stephen H. Fischer]

Hi,

Only when we can compare the 6847 and the 6847T1.

Another interesting comparison would be the 6845 and the 6847.

Then comparing the 684X with the 6545.

Synertek always added features to one up Motorola. Perhaps the 6545 was pin 
compatible with the 6847T1.

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
>>