hockley@ENSU.UCALGARY.CA (Dallas C. Hockley) (05/18/91)
help! I am trying to determine whether output from a GS/OS device driver call is routed through the serial port firmware or not. If a sequence of charcters which can be interpreted as a control sequence for the firmware is to be transmitted, how can the control be embedded or otherwise stopped from executing routines in the communication hardware? Dallas Dallas Hockley hockley@ensu.ucalgary.ca StarGazer at the Data Systems BBS (403)278-0492
mattd@Apple.COM (Matt Deatherage) (05/20/91)
In article <9105171740.AA09361@ensu.ucalgary.ca> hockley@ENSU.UCALGARY.CA (Dallas C. Hockley) writes: >help! I am trying to determine whether output from a GS/OS device driver call >is routed through the serial port firmware or not. If a sequence of charcters >which can be interpreted as a control sequence for the firmware is to be >transmitted, how can the control be embedded or otherwise stopped from >executing routines in the communication hardware? > Well, this isn't as easy as I had thought. The trick to knowing that you can send firmware commands through a GS/OS driver is to see if the driver is "generated" - if it's a default driver GS/OS creates to interface with the firmware. If it's a generated driver for any character or block device, all I/O is done by GS/OS through the normal Apple II firmware on the peripheral card/port. The problem is that the reference material doesn't seem to have any information on how to do this. I had thought you could see if a device was generated by looking at bit 14 of the device characteristics word (returned from DInfo). However, the A-W GS/OS Reference says that bit 14 is for "linked" devices (one of several partitions) and that bit 13 is reserved. My memory says that bit 13 is for linked devices. I don't have a final GS/OS Device Driver Reference here at home and I'm in ProDOS 8 (where's that GS/OS version of ProTERM, anyway?) so I can't use the Exerciser DA to check it out. But I'll bet the A-W book is wrong. -- ============================================================================ Matt Deatherage, Developer Technical | The opinions expressed herein are Support, Apple Computer, Inc. | not those of Apple Computer, and Personal mail only, please. Thanks. | shame on you for thinking otherwise. ^^^^^^^^ Technical questions are not personal. Please post them instead. ============================================================================
JWANKERL@UTCVM.BITNET ("Josef W. Wankerl") (05/20/91)
On Sun, 19 May 91 17:59:09 GMT Matt Deatherage said: >In article <9105171740.AA09361@ensu.ucalgary.ca> hockley@ENSU.UCALGARY.CA > (Dallas C. Hockley) writes: >>...If a sequence of charcters >>which can be interpreted as a control sequence for the firmware is to be >>transmitted, how can the control be embedded or otherwise stopped from >>executing routines in the communication hardware? Well, I assume you're trying to write some kind of program to communicate with a super serial card and you're trying to send a control-a (the command character). There are two ways to approach this problem - the first, and efficient, way is to disable your command character recognition by sending control-a Z. This has a drawback, however... you can never issue commands to the ssc again. The other way is to first change the command character to something else. Send control-a, some other control character (like control-b) - this changes the command character to control-b, send control-a (this sends the character through the ssc), send control-b, send control-a (this sets the command character back to control-a). This lets you issue commands to the ssc later on. >I don't have a final GS/OS Device Driver Reference here at home and I'm in >ProDOS 8 (where's that GS/OS version of ProTERM, anyway?) so I can't use the >Exerciser DA to check it out. But I'll bet the A-W book is wrong. Page 232, Apple IIGS GS/OS Device Driver Reference - character device status word: bit 14 - linked device, bit 13 - background busy. (bit 5 - no-wait mode, which is wrong, right Matt? :-) >-- >============================================================================ >Matt Deatherage, Developer Technical | The opinions expressed herein are >Support, Apple Computer, Inc. | not those of Apple Computer, and >Personal mail only, please. Thanks. | shame on you for thinking otherwise. >^^^^^^^^ Technical questions are not personal. Please post them instead. >============================================================================ -- ===> Josef W. Wankerl, Technical Editor for GS+ Magazine BITNET: JWANKERL@UTCVM.BITNET | America Online: JWankerl ProLine: jwankerl@pro-gsplus |-------------------------------- Internet: jwankerl@pro-gsplus.cts.com | "I am a Viking" -Y. Malmsteen