[comp.sys.transputer] MemStart

norman@cs.purdue.EDU (Victor Todd Norman) (08/03/90)

Question:  What is MemStart?  I'm looking all through the INMOS
Transputer Instruction Set: A compiler writers guide to find where
this thing is defined, and I can't find it!  I suppose it is either
0x80000000 or 0x80000800.  I find the reference to MemStart on page 74.

Vic Norman

zenith-steven@cs.yale.edu (Steven Ericsson Zenith) (08/03/90)

In article <11303@medusa.cs.purdue.edu>, norman@cs.purdue.EDU (Victor
Todd Norman) writes:
|> Question:  What is MemStart?  I'm looking all through the INMOS
|> Transputer Instruction Set: A compiler writers guide to find where
|> this thing is defined, and I can't find it!  I suppose it is either
|> 0x80000000 or 0x80000800.  I find the reference to MemStart on page
74.


MemStart is an address at a device dependent offset from the base of
memory.
You should checkout the data sheet for the devices you are programming
but
for example for a T425 it's #80000070, for a T414 it's #80000048. The
T800
is the same as the T425.

--
Steven Ericsson Zenith              *            email:
zenith@cs.yale.edu
Fax: (203) 466 2768                 |            voice: (203) 432 1278
"The tower should warn the people not to believe in it." -
P.D.Ouspensky
Yale University Dept of Computer Science 51 Prospect St New Haven CT
06520 USA

des@elberton.inmos.co.uk (David Shepherd) (08/07/90)

In article <11303@medusa.cs.purdue.edu>, norman@cs.purdue.EDU (Victor
Todd Norman) writes:
|> Question:  What is MemStart?  I'm looking all through the INMOS
|> Transputer Instruction Set: A compiler writers guide to find where
|> this thing is defined, and I can't find it!  I suppose it is either
|> 0x80000000 or 0x80000800.  I find the reference to MemStart on page 74.

quite correct .... MemStart is not defined in TIS-CWG. It ought to be
there, probably on p84 in a new section before special workspace locations.
The text of the section should be something like:

  MemStart is the address of the first word above the special RAM
  locations at the bottom of the memory map. Because different transputer
  variants store different information in these special RAM locations
  MemStart differs between variants. The values for current processors
  are

     IMS T212:  #8024
     IMS T414:  #80000048
     IMS T425:  #80000070
     IMS T800:  #80000070

  the values for these and other variants are given in the relevant
  datasheets.


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