[Coco] Rare item: PHB 80 Column card - Yes PHB not PBJ!

Retro Canada retrocanada76 at gmail.com
Sat Sep 21 22:09:31 EDT 2013


i found that in the full turn of the screw pag 130 in the article increasing character display  there is the schematics of a disto 80 column add on based on the same chip crt9128 although the ports are different this board was based on that design.



On 2013-09-21, at 12:28 AM, Arthur Flexser <flexser at fiu.edu> wrote:

Maybe the PBJ (yes, PBJ, not PHB!) Basic driver, if you could find a
copy, could be used with it, at least as a starting point, if you
modified that driver's the base address, depending on how similar the
6845 is to the chip this thing contains.

Art

On Sat, Sep 21, 2013 at 12:01 AM, Luis Antoniosi (CoCoDemus)
<retrocanada76 at gmail.com> wrote:
> Ok following the datasheet this card is pretty simple in function:
> 
> FF79 for register/status on bit 7
> FF78 for read/write data
> 
> The display is already set when you turn it on but it has an overscan. No
> way to tune this, seems to be hardware. There is no register for that.
> 
> But I'm happy because it works i could move cursor, set reverse video,
> write a char, scroll up/down.
> 
> This chip has nice features over the 6845 like underline, blinking or
> reverse video, smooth scroll up/down, etc
> 
> It has a semigraphics, thin and wide mixed with text
> 
> It has a 25th non scrolling line (selectable by software) and the PCB is
> pretty damn simple. a good project for hobbysts.
> 
> 
> On Fri, Sep 20, 2013 at 9:12 PM, Gene Heskett <gheskett at wdtv.com> wrote:
> 
>> On Friday 20 September 2013 21:06:55 Luis Antoniosi (CoCoDemus) did opine:
>> 
>>> Ok got the FF78/79 as registers by randomly pokeing things.
>>> Investigations proceed.
>> IIRC the other 2, which s/b at $FF7A & $FF7B, may not be readable.  But
>> this is sure sounding like mine, which I had to re-adjust to $FF78-7B
>> 
>> If you find something at $FF76 or 77m then its the original broken adress
>> as that used half of each of 2 adjacent 4 byte wide blocks.  Thats a
>> hanging offense on the coco, wasting an address block that way.
>> 
>> The other addresses you quoted are in the middle of the GIME on a coco3.
>> That is an absolute no-no.
>>> 
>>> 
>>> On Fri, Sep 20, 2013 at 8:31 PM, Luis Antoniosi (CoCoDemus) <
>>> 
>>> retrocanada76 at gmail.com> wrote:
>>>> Hi all,
>>>> 
>>>> I got this prototype and no drivers:
>>>> 
>>>> https://twitter.com/RetroCanada76/status/381207331813343233/photo/1/la
>>>> rge
>>>> https://twitter.com/RetroCanada76/status/381211654903459841/photo/1/l
>>>> arge
>>>> 
>>>> I don't believe you ever heard of it. The label says:
>>>> 
>>>> PHB COMPUTER PRODUCTS INC.
>>>> 1923 ANTOINE DRIVE-SUITE B-3
>>>> HOUSTON TEXAS 77055
>>>> 
>>>> PROTOTYPE 80 COLUMN CARD
>>>> FOR
>>>> RADIO SHACK COLOR COMPUTER
>>>> 
>>>> 
>>>> But I may ask: Just looking to the photos is it possible to find which
>>>> hardware register is this card set ? The PBJ uses FF98/FF99/FF9B but
>>>> what about this one ?
>>>> 
>>>> And how close to the 6845 would this beast be ?
>>>> 
>>>> 
>>>> thxs!
>>>> 
>>>> --
>>>> Long live the CoCo
>> 
>> 
>> Cheers, Gene
>> --
>> "There are four boxes to be used in defense of liberty:
>> soap, ballot, jury, and ammo. Please use in that order."
>> -Ed Howdershelt (Author)
>> My web page: <http://gene.homelinux.net:6309/gene> should be up!
>> 
>> The man who understands one woman is qualified to understand pretty well
>> everything.
>>                -- Yeats
>> A pen in the hand of this president is far more
>> dangerous than 200 million guns in the hands of
>>         law-abiding citizens.
>> 
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> 
> 
> 
> --
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> 
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