Description: Apple II Peripheral Cards: How Pascal identifies (2/97)
Header: Apple II Peripheral Cards: How Pascal identifies (2/97)

 Apple II Peripheral Cards: How Pascal identifies (2/97)

 Article Created: 27 July 1985
 Article Reviewed/Updated: 12 Feb 1997

 TOPIC -----------------------------------------------------------

 This article discusses how Pascal v1.1 identifies peripheral cards.

 DISCUSSION ------------------------------------------------------


 Pascal 1.1 uses four firmware bytes to identify the peripheral card. Both the
 identifying bytes and the branch table are near the beginning of the $Cs00
 ROM space (where s = slot). The identifiers are listed in Table A-2.

 Address      Value
 _______________________________________________________________

 $Cs05        $38  (like the old Serial Interface Card)
 $Cs07        $18  (like the old Serial Interface Card)
 $Cs0B        $01  (like Generic Signature of new FW cards)
 $Cs0C        $ci  (like Device Signature; see below)

             Table A-2. Bytes Used for Device Indentification

 The first digit, c, of the Device Signature byte indentifies the device class
 as listed in Table A-3.

 Digit        Class
 _______________________________________________________________

 $0           reserved
 $1           printer
 $2           joystick or other X-Y input device
 $3           serial or parallel I/O card
 $4           modem
 $5           sound or speech device
 $6           clock
 $7           mass storage device
 $8           80-column card
 $9           network or bus interface
 $A           special purpose (none of the above)
 $B-F         reserved for future expansion

             Table A-3. Device Class Digit

 The second digit, i, of the Device Signature byte is a unique indentifier for
 the card, assigned by Apple Developer Technical Support. For example, in the
 Device Signature of the SSC--$31--the 3 signifies that the device is a serial
 or parallel I/O card; the 1 is Apple Developer Technical Support's unique
 identifier for that card.


 Article Change History:
 12 Feb 1997 - Reviewed for technical accuracy, revised formatting.
 Copyright 1985-97, Apple Computer, Inc.
 Keywords: