SSC Commands

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SSC Commands

Are there any keyboard commands that will tell me how the Super Serial Card is set up?

CWJ_Wilko's picture
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Re: SSC Commands

Hey - me again!

You're probably best looking through the manual: http://www.apple2online.com/web_documents/Apple%20II%20Super%20Serial%20Card%20Installation%20&%20Operating%20Manual.PDF

I know it took a bit of patience with mine to get it working with ProTERM. What do you want to use the SSC for?

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Re: SSC Commands
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Re: SSC Commands

I want to use it for Amateur Radio , packet radio. I want to connect to Terminal Node Controllers.

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Re: SSC Commands


I didn't see any reference to a command that would show me how the SSC is configured.

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Re: SSC Commands

You need to take a look at the DIP Switch setting of your card

and this needs to be compared with the Documentation. This will give you the information how your card is configured.
As far as I remember there isn't any other way to get this information.

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Re: SSC Commands

rick71 wrote:

I didn't see any reference to a command that would show me how the SSC is configured.

That part of the reply was not adressing to you but instead to CWJ_Wilko, who was asking
what you want to use the SSC for....
propbably you missed that part of the question in the posting before ?

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Re: SSC Commands

tokabln wrote:
You need to take a look at the DIP Switch setting of your card
and this needs to be compared with the Documentation. This will give you the information how your card is configured.
As far as I remember there isn't any other way to get this information.

I looked up the switch settings before I set the switches. However, commands can be issued by software or from the keyboard which can override the switches. I want to know what the computer "thinks" the card is set to at any given time.

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Re: SSC Commands

Hello Rick71,

maybe this is what you are looking for:

Key Super Serial Card (SSC) Memory Locations for Programmers

All addresses are of the form '$C0sx', where 's' is the Slot number
of the SSC plus $8 and 'x' is the final digit ($0 - $F) of the
address.

Control Register

The 6551 Control Register is mapped to $C0sB
($C09B for Slot 1, $C0AB
for Slot 2, etc.).
Its format is ...
bit 7 : stop bit number [0= 1 stop bit, 1= 2 stop bits for most
settings, except: 1.5 stop bits for word length 5 and no parity,
and 1 for word length 8 and parity]
bits 6 and 5 : word length
[00= 8 bits, 01= 7 bits, 10= 6 bits, 11= 5 bits]

bit 4 : receiver clock source [0= external, 1= internal]

bits 3, 2, 1, 0 : baud rate, as follows:
0000= 16x external clock
0001= 50 bps
0010= 75 bps
0011= 109.92 bps
0100= 134.58 bps
0101= 150 bps
0110= 300 bps
0111= 600 bps
1000= 1200 bps
1001= 1800 bps
1010= 2400 bps
1011= 3600 bps
1100= 4800 bps
1101= 7200 bps
1110= 9600 bps
1111= 19200 bps

Note that 1 MHz Apples (everything other than the Apple IIgs and //c
Plus running in "fast" mode) cannot handle 19.2 kbps, and even 9600
bps on these machines requires either some highly optimised code or
a decent buffer in the device being accessed. The faster Apples
have no difficulty with this speed, however.

Command Register

The 6551 Command Register is mapped to $C0sA, and is essentially an
extension of the Control Register.

Its format is ...
bits 7 and 6 : parity mode control [00= odd parity, 01= even parity,
10= mark parity (parity bit always set),
11= space parity
(parity bit always cleared)]

bit 5 : parity mode enable [0=no parity used, 1=parity used]
bit 4 : receiver mode echo [0=no echo, 1=echo]
bits 3 and 2 : transmitter interrupt control
[00= set RTS high and transmit no interrupts,
01= set RTS low and transmit interrupts,
10= set RTS low and transmit no interrupts,
11= set RTS low and
transmit break signals instead of interrupts]

bit 1 : interrupt request disable
[0=enable receiver interrupts,
1=disable receiver interrupts]
bit 0 : Data Terminal Ready (DTR) setting
[0=set DTR high (indicates 'not ready'),
1=set DTR low (indicates 'ready')]

Note that, although the DTR is generally not used in the SSC
(it may actually not be connected!), it must be set to 'low' in order for the
6551 to function correctly. Also, the RTS signal must be set 'low'
in order to receive any incoming data from the serial device.

Note also that both the Command and Control registers are write-only,
which means that reading them will not necessarily yield valid data
on the device's settings. If there is any doubt as to the current
settings of the 6551, you should (re)initialise them.

Status register

The 6551 Status register is mapped to $C0s9. It is a read-only register
and its format is ...

bit 7 : interrupt [0=no interrupt, 1=interrupt]
bit 6 : Data Set Ready (DSR) [0=DSR low (ready), 1=DSR high (not ready)]
bit 5 : Data Carrier Detect (DCD) [0=DCD low (detected), 1=DCD high (not detected)]
bit 4 : transmitter data register empty [0=not empty, 1=empty]
bit 3 : receiver data register full [0=not full, 1=full]
bit 2 : overrun error [0=no error, 1=error]
bit 1 : framing error [0=no error, 1=error]
bit 0 : parity error [0=no error, 1=error]

Data Register
The Data Register at $C0s8 is used both for outgoing and incoming data.
Whether the data has been sent or received can be determined by checking
bits 4 and 3 (respectively) of the Status register.

I hope that this is the SSC programming information that you are looking for.

sincerely speedyG

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Re: SSC Commands

Wow. I'd have to take a couple of classes just to understand that stuff Smile
Thanks, though. I'll try to figure it out.

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