[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Apple II keyboard encoder - need specs for optional right-angle slide switch
On May 10, 10:14 am, Michael Black <et...@ncf.ca> wrote:
> On Wed, 9 May 2012, Michael J. Mahon wrote:
> > Ralph wrote:
> >> I'm trying to track down details on adding a keyswitch to the Apple II
> >> plus keyboard encoder.
>
> >> I have a vague recollection of a specific "Apple Cart" article from an
> >> 1980 or 1981 issue of Creative Computing, it discusses the keyboard
> >> encoder board on the Apple II plus, and mentions the specific C&K
> >> switch part number that can be soldered onto the board to achieve
> >> full character set generation (upper and lower case ASCII, and getting
> >> ctrl-shift-P to generate the '@' sign) from the normally upper-case
> >> ASCII only keyboard. I did ask a few people in person over last
> >> weekend, but they unsurprisingly couldn't come up with an exact part #
> >> after 30 years.
> >> (Atariarchives doesn't have these Creative Computings scanned in)
>
> >> Thanks!
>
> >> - Ralph
>
> >> BTW, I found this gem of an article from M. Horton (previously at Bell
> >> Labs), posted in 1983 - linking offsite
>
> >>http://www.megalextoria.com/usenet-archive/news042f1/b62/net/internat...
> >> (well-formatted ASCII version)
>
> >>http://groups.google.com/group/net.internat/msg/a319f7b375fc6e55
> >> (mangled Google Groups version)
>
> > Interesting article on a fundamentally broken topic: keyboards.
>
> > WRT the encoder board having an unfilled position for a switch
> > that "normalizes" the ][+ keyboard, wow--how could such a common
> > desire be so easily filled and yet remain so obscure?
>
> It should be simple, since upper and lower case are identical except for
> a couple of bits. Indeed, control characters are the same, minus the high
> bits:
> A $41 1000001
> a $61 1100001
> ctrl-A $01 0000001
>
> A few gates can start playing with the output of the encoder, which may be
> what the first poster is not fully remembering.
>
> I don't have the schematic for the Apple II handy, so I don't remember
> what's in there.
>
> Michael
On May 10, 10:14 am, Michael Black <et...@ncf.ca> wrote:
> On Wed, 9 May 2012, Michael J. Mahon wrote:
> > Ralph wrote:
> >> I'm trying to track down details on adding a keyswitch to the Apple II
> >> plus keyboard encoder.
>
> >> I have a vague recollection of a specific "Apple Cart" article from an
> >> 1980 or 1981 issue of Creative Computing, it discusses the keyboard
> >> encoder board on the Apple II plus, and mentions the specific C&K
> >> switch part number that can be soldered onto the board to achieve
> >> full character set generation (upper and lower case ASCII, and getting
> >> ctrl-shift-P to generate the '@' sign) from the normally upper-case
> >> ASCII only keyboard. I did ask a few people in person over last
> >> weekend, but they unsurprisingly couldn't come up with an exact part #
> >> after 30 years.
> >> (Atariarchives doesn't have these Creative Computings scanned in)
>
> >> Thanks!
>
> >> - Ralph
>
> >> BTW, I found this gem of an article from M. Horton (previously at Bell
> >> Labs), posted in 1983 - linking offsite
>
> >>http://www.megalextoria.com/usenet-archive/news042f1/b62/net/internat...
> >> (well-formatted ASCII version)
>
> >>http://groups.google.com/group/net.internat/msg/a319f7b375fc6e55
> >> (mangled Google Groups version)
>
> > Interesting article on a fundamentally broken topic: keyboards.
>
> > WRT the encoder board having an unfilled position for a switch
> > that "normalizes" the ][+ keyboard, wow--how could such a common
> > desire be so easily filled and yet remain so obscure?
>
> It should be simple, since upper and lower case are identical except for
> a couple of bits. Indeed, control characters are the same, minus the high
> bits:
> A $41 1000001
> a $61 1100001
> ctrl-A $01 0000001
>
> A few gates can start playing with the output of the encoder, which may be
> what the first poster is not fully remembering.
>
> I don't have the schematic for the Apple II handy, so I don't remember
> what's in there.
>
> Michael
On May 10, 10:14 am, Michael Black <et...@ncf.ca> wrote:
> On Wed, 9 May 2012, Michael J. Mahon wrote:
> > Ralph wrote:
> >> I'm trying to track down details on adding a keyswitch to the Apple II
> >> plus keyboard encoder.
>
> >> I have a vague recollection of a specific "Apple Cart" article from an
> >> 1980 or 1981 issue of Creative Computing, it discusses the keyboard
> >> encoder board on the Apple II plus, and mentions the specific C&K
> >> switch part number that can be soldered onto the board to achieve
> >> full character set generation (upper and lower case ASCII, and getting
> >> ctrl-shift-P to generate the '@' sign) from the normally upper-case
> >> ASCII only keyboard. I did ask a few people in person over last
> >> weekend, but they unsurprisingly couldn't come up with an exact part #
> >> after 30 years.
> >> (Atariarchives doesn't have these Creative Computings scanned in)
>
> >> Thanks!
>
> >> - Ralph
>
> >> BTW, I found this gem of an article from M. Horton (previously at Bell
> >> Labs), posted in 1983 - linking offsite
>
> >>http://www.megalextoria.com/usenet-archive/news042f1/b62/net/internat...
> >> (well-formatted ASCII version)
>
> >>http://groups.google.com/group/net.internat/msg/a319f7b375fc6e55
> >> (mangled Google Groups version)
>
> > Interesting article on a fundamentally broken topic: keyboards.
>
> > WRT the encoder board having an unfilled position for a switch
> > that "normalizes" the ][+ keyboard, wow--how could such a common
> > desire be so easily filled and yet remain so obscure?
>
> It should be simple, since upper and lower case are identical except for
> a couple of bits. Indeed, control characters are the same, minus the high
> bits:
> A $41 1000001
> a $61 1100001
> ctrl-A $01 0000001
>
> A few gates can start playing with the output of the encoder, which may be
> what the first poster is not fully remembering.
>
> I don't have the schematic for the Apple II handy, so I don't remember
> what's in there.
>
> Michael
Here's what I've found so far - I'm probably off to a library to see
if my recollection about the
"Apple Cart" column mentioning a C&K part number is true.
http://www.classiccmp.org/pipermail/cctalk/1998-September/161990.html
has an excellent
summary of the keyboard encoder on the Apple ][+..
The keyboard schematic in the "Apple II reference manual" (figure 17)
doesn't show the
option (it looks like the older design with the MM5740), but Sather's
documentation shows
the AY-5-3600 with pins B8 and B9 routed through an optional switch
(S2), to permit the CTRL
and SHIFT keys to set additional address bits on the keyboard encoder.
The Sathers's "Understanding the Apple II" (pages 7-16 through 7-18)
shows a revised keyboard
encoder schematic for the Apple II plus.
This probably didn't get more visibility in the Apple community
because Apple didn't actively
promote it, and because the Shift-key mod using the game IO port was
too well established.
Also, the Apple II firmware was never modified to handle lower-case
input from this keyboard
encoder change.
By cutting two traces on the keyboard encoder card, and installing the
S2 switch, the
stock Apple keyboard encoder will generate the ASCII codes for lower
and upper case characters.
They will not display unless you already have a lower case character
generator chip.
I found surplus C&K 1201 right-angle switches which include metal
prongs for PC board mounting,
but there are no corresponding holes on the area of the PCB where they
fall. In fact, it almost looks
like a toggle switch, but not a slide switch was intended to go
there. There's a dashed line indicating
a switch handle, but it looks like it was designed with a toggle
switch in mind.
This makes me think there's a different part number for the switches
that go into the Apple,
since the Apple keyboard encoder board would be scratched by the
prongs.
The C&K 1201 switch is a right-angle slide switch with many of the
right features (accurate
pin spacing, long switch handle that can reach the edge of the
keyboard encoder PCB),
but I'd love to see this confirmed in writing somewhere.
I've gone through these Creative Computing back issues, but haven't
found that column yet:
1982 (jan, feb, apr, may)
1981 (mar, apr, may, jun)
1980 (jan, feb, mar, apr, may, jun, jul, sept, oct, nov - missing
august & december)
By 1983, the Apple //e was out, so I don't think Creative Computing
would have published anything specific
to the II+ after that date.