murakami@m.cs.uiuc.edu (09/15/89)
I bought the A2286 AT bridgeboard to run Smalltalk V/286 and had the same problem. I reported it to C-A via BIX and phoned people at both C-A and Digitalk. As I understand it, Digitalk is sending some info to C-A which details the BIOS fix that is needed. I don't know if/when a fix will be available, but C-A is aware of the problem. I've attached the messages that I posted to BIX. -Gary ========================== amiga.dev/janus #299, from murakami, 788 chars, Thu Sep 7 03:13:37 1989 -------------------------- TITLE: Smalltalk/V286 versus the A2286 I recently purchased an A2286 bridgeboard with the express purpose of running Smalltalk/V286 from Digitalk, Inc. However, the A2286 does not appear to be compatible enough to run Smalltalk/V286 (the A2286 reboots). I called Digitalk at (213)645-1082 and talked to Mike Anderson. He said that other PC/AT compatible manufacturers had the same problem and fixed the incompatibility in the BIOS. He is willing to talk to someone from C-A to help make the A2286 more compatible so that it will function with Smalltalk/V286. Is C-A willing to look into a fix for the A2286 (for Smalltalk/V286)? Am I out of luck with the A2286? Is there hoep for a future 386 board? I need to know within the 60 day refund period for Smalltalk/V286. Thanks, -Gary ========================== amiga.dev/janus #300, from murakami, 2040 chars, Thu Sep 7 03:27:43 1989 This is a comment to message 299. There are additional comments to message 299. -------------------------- Here is some more information on the problem (excerpts from the "Smalltalk/V 286 Tutorial and Programming Handbook", pp. 507-508). 80386 cpu vs 80286 cpu Since Smalltalk/V 286 runs in protected mode, and all of the BIOS and DOS facilities are accessible only from real mode, switching from protected to real mode is necessary. If you have a 80386 cpu, this switching is done via 80386 software instructions. Smalltalk/V detects the presence of the 80386 cpu automatically. If you have an 80286 cpu, then the switching between protected and real mode is accomplished by causing the 80286 cpu to shutdown and restart in real mode. There are two issues, how to accomplish the shutdown and how th cpu is to start up. 80286 Shutdown The /s: parameter specifies the type of shutdown to use. There are two choices: shutdown via hardware, /s:h, and via software, /s:s. The hardware shutdown is done by intentionally causing what is commonly known as a triple fault condition in the 80286 cpu. This does require that the mother board cause an automatic restart condition when the 80286 enters the shutdown mode. All IBM PC/AT machines and most clones do this. The software shutdown is done by requesting a cpu reset via software. This involves sending commands to the keyboard processor on AT class machines and issuing port I/O commands on some PS/2 machines. 80286 Restart The /t: parameter specifies how the 80286 is to start up after a shutdown. This is done by writing a value into the CMOS memory (non-volatile memory) of the machine prior to the shutdown. The BIOS boot up code in the ROM looks at this value to determine the type of restart to do. There are two choices: primary start up, /t:p, and secondary startup /t:s. The primary start up is done by using the documented BIOS function for starting up after switching from protected to real mode. For early PC/AT's and some clones, this function does not work properly. The secondary start up uses the BIOS block memory move function to cause the real mode start up.