[Coco] 256K J&R Banker and OS-9

[A Schober]

After some rifling through boxes, I've found a
discussion of this product in Hot Coco, Sept 1985, pp.
28--31 (Schematic + test program).  Maybe some
relevant info:

QUOTE

...you have either 4 banks of 64K or eight banks of
32K.  You switch memory addresses using PEEK commands
to the following addresses:

ffc0-ffc7 64k bank select
ffc8-ffcf 32k bank select
ffd0-ffd7 vdg select
ffd8-ffdf reserved for future 512K upgrade

. . .

J&R's upgrade design is, as far as we know, compatible
with the stock 64K CoCo with one exception.  A problem
arises if you program the SAM using the CLR command,
because a CLR command PEEKs and the POKEs 00s to
memory.  You can fix this by replacing all offending
CLR commands with STA commands (e.g. STA $ffc0).

. . .

PEEKs needed to change the graphics memory page
accessed by the VDG:

peek   vdg bank
ffd0   0
ffd1   1
etc...
ffd7   7
ffd8-ffdf reserved for future expansion

       0000-7fff   8000-feff
peek  lower bank   upper bank
ffc0   0            0
ffc1   1            1
ffc2   2            2
etc...
ffc7   7            7
ffc8   0            1
ffc9   0            2
ffca   0            3
etc...
ffcf   0            7

END

Maybe this is helpful?

-Arnold Shober

--- Robert Gault <robert.gault at worldnet.att.net>
wrote:

> At the very least, make the documentation available.
> New drivers could 
> be written if needed.
> 
> Bruce W. Calkins wrote:
> > Regrettably, Most of my CoCo's have been in
> storage since my move summer 
> > '04.   So I've done little with them.
> > 
> > The J & R Banker requires a change in the boot
> sector of the OS-9 Level 
> > One disk.  The program is in RS-Basic, so someone
> with a understanding 
> > of what's where on the OS-9 disk should be able to
> figure out what is 
> > changed to accommodate the increased RAM.
> > 
> > In Summary, the J & R Banker operates in 64k for
> OS-9 Level One, with 
> > the availability of a RAM-Disk, and I expect it
> will do the same for 
> > NITROS9 L1 for CoCo 1 machines.  The lack of CoCo
> 3 specific hardware 
> > will limit its use of the 9309 optimized code as
> used in the CoCo 3.
> > 
> > Do you need the documentation and/or the software
> that goes with the 
> > hardware?
> > 
> > Bruce W.
> > 
> > 
> > Boisy Pitre wrote:
> > 
> >> Bruce Calkins and I had some discussion about
> this, though I don't  
> >> think I ever got any driver software from him. 
> If you come across  
> >> it, let me know and I'll put it in the NitrOS-9
> Project repository.
> >>
> >> Boisy
> >>
> >> On Dec 28, 2005, at 7:59 AM, A Schober wrote:
> >>
> >>> I have come across a 256K J&R Banker in a CoCo I
> (with
> >>> 6309!).  Is it possible to run OS9/L2 (or
> NitrOS9)
> >>> with such a memory switcher?
> >>>
> >>> Thoughts?
> >>>
> >>> -Arnold Shober
> >>>
> >>>
> >>>            __________________________________
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> >>
> >>
> >>
> > 
> > 
> 
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