dsc@drutx.ATT.COM (DavisCS) (08/28/87)
Problem with AUTCAD and the PC6300+
A friend has been successfully running AUTOCAD on an AT&T PC6300+ with
512k of memory. After filling out to 1Mb the program will not work.
Does anyone have any ideas as to what the problem may be? Please post
to the net.
Posted for
Eric Puetz ...sw013B!epp (rest of net address unknown)
(314) 391-3116 voicevg55611@ihuxy.ATT.COM (gopal) (08/29/87)
In article <5118@drutx.ATT.COM>, dsc@drutx.ATT.COM (DavisCS) writes: > Problem with AUTCAD and the PC6300+ > A friend has been successfully running AUTOCAD on an AT&T PC6300+ with > 512k of memory. After filling out to 1Mb the program will not work. > Does anyone have any ideas as to what the problem may be? Please post > to the net. > Posted for Eric Puetz ...sw013B!epp (rest of net address unknown) > (314) 391-3116 voice Yes - the reason is that AUTOCAD checks the ROM ID byte to see if it the machine is IBM PC/XT or an IBM AT. But the machine is a 6300 plus, which has an XT architecture but an AT ROM ID byte. Anyway, since AUTOCAD thinks that it is an IBM AT, it looks to see if there is any expanded memory (paged) - if you have extended memory over 640K, the call to check for expanded memory comes back with the amount of extended memory in the plus. AUTOCAD tries to use this **expanded** memory that it found... and you know the result. Possible solutions - 1) Keep the 6300+ to 640K of memory. 2) May be the memory extension card can be configured to provide true expanded memory 3) Get AUTOCAD to write a version for the 6300 plus. 4) Get AT&T to modify (don't remember now if it was the DOS call or BIOS call) the ROM or AT&T MS-DOS so that this memory does not show up as expanded memory - this might make other programs not work though. 5) Patch AUTOCAD 6) Patch ROM ID byte. None seem like good solutions but at least your curiosity must be satisfied. Venu P. Gopal ihnp4!ihuxy!vg55611