[comp.sys.ibm.ps2.hardware] Microchannel Specs Wanted

jnb10@ccc.amdahl.com (Joe Boucher) (01/12/91)

I am looking for as much technical info as I can get on Microchannel.

I have a 55 SX and would like to build some interface boards. Is the
information itself licensed by IBM, or is it freely available as it is
with the AT bus? I can't seem to get an answer from IBM reps as to whether
or not the info is in the Technical Ref Manual.

Does anyone have any suggestions for any books that might have complete
specs (enough to design from), or anywhere else that I might try.

Thanks in advance.
Joe Boucher

feustel@netcom.UUCP (David Feustel) (01/13/91)

Try the Micro Channel Architecture Handbook (Brady Books, ISBN
0-13-583493-7, $29.95). 

Somewhat propagandistic and full of typos, but contains a fair amount
of useful info on Microchannel. The big question for me is how much of
the full Microchannel spec is implemented in currently available IBM
machines.
-- 
David Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805, (219) 482-9631
EMAIL: netcom.uucp

ccastd2@prism.gatech.EDU (Dale Phurrough) (01/13/91)

jnb10@ccc.amdahl.com (Joe Boucher) writes:

>I am looking for as much technical info as I can get on Microchannel.

>I have a 55 SX and would like to build some interface boards. Is the
>information itself licensed by IBM, or is it freely available as it is
>with the AT bus? I can't seem to get an answer from IBM reps as to whether
>or not the info is in the Technical Ref Manual.

>Does anyone have any suggestions for any books that might have complete
>specs (enough to design from), or anywhere else that I might try.

>Thanks in advance.
>Joe Boucher

I thought the whole deal with Microchannel was that the specs were patented
by IBM nothing...including wiring info could be gotten without paying IBM
a hugh lump.  Yousee IBM screwed up by not doing the same thing with ISA.
Company after company copied their standard and IBM lost out.

Although...I could be wrong!

-- 
Lamborghini Diablo ===---->  the latest and fastest....
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp:	  ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!ccastd2
Internet: ccastd2@prism.gatech.edu

andrew@ramona.Cary.NC.US (Andrew Ernest) (01/13/91)

I've got the "IBM Personal System/2 Hardware Interface Technical
Reference" and it includes, among others, the following sections:

	Micro Channel (tm) Architecture
		Channel Definition
			Signal Descriptions
			Micro Channel Connector
			Channel Signal Groups
		Bus Ownership
		Channel Support
		Level-Sensitive Interrupt Sharing
		Micro Channel Critical Timing Parameters
		DMA Timing
		...
	Programmable Option Select
		Card Selected Feedback
		System Board Setup
		Adapter Setup
		Adapter POS Implementation
		POS Implementation Procedure
		System Configuration Utilities
		Adapter Description Files
	Micro Channel Adapter Design
		Dimensions
		Power
		Voltage Regulation
		General Design Considerations
		Design Guidelines

I've left out some of the headings to save typing...I just wanted
to give you a flavor of what's in the book.  There are timing diagrams
and adapter drawings (with dimensions).  I can't comment on the
accuracy and completeness of the info because I'm not a hardware
hack.
-- 
Andrew Ernest <andrew@ramona.Cary.NC.US>

jgb@prism.gatech.EDU (James G. Baker) (01/14/91)

In article <85TA02Rz04Ep01@JUTS.ccc.amdahl.com> jnb10@juts.ccc.amdahl.com (Joe Boucher) writes:
>I am looking for as much technical info as I can get on Microchannel.

The true-blue IBM technical reference has served me well.  I have the MCA
info and also the model 50,60,70,80 info (POS and some I/O are machine-
specific).   

The SAMS PS/2 Tech guide and Eggebrecht's Interfacing to the PC/AT/PS/2 has
also helped to provide different wording from IBM's info.

If you just need to make a MCA card, that should do very well.  I've seen
SAMS schematics, diagrams for the models 30 and 50, but not any 386 ones - and 
I haven't bought any yet. 

Good luck.
-- 
BAKER,JAMES G - Lab Technician, School of Electrical Engineering
Georgia Institute of Technology, Atlanta Georgia, 30332
uucp:	  ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!jgb 
Internet: jgb@prism.gatech.edu

bank@lea.ncsu.edu (Dave The DM) (01/19/91)

In article <85TA02Rz04Ep01@JUTS.ccc.amdahl.com> jnb10@juts.ccc.amdahl.com (Joe Boucher) writes:
>I am looking for as much technical info as I can get on Microchannel.
>
>I have a 55 SX and would like to build some interface boards. Is the
>information itself licensed by IBM, or is it freely available as it is
>with the AT bus? I can't seem to get an answer from IBM reps as to whether
>or not the info is in the Technical Ref Manual.
>
>Does anyone have any suggestions for any books that might have complete
>specs (enough to design from), or anywhere else that I might try.
>
>Thanks in advance.
>Joe Boucher

   You'll have to get the specs from IBM, as far as I know. I don't
know what the cost involved is, but I do know that part of the bus
design involves embedded ROMs with, you guessed it, throughly
copyrighted code.

   As clean as the bus design might be, its a tangle of legal
ownership, patents, and copyrights.

   You're pretty much stuck with IBM as your sole source of info,
unless you want to try to contat a company that has made an
MCA board and weasel it out of them.

   I don't see that Big Blue would be all that reluctant to give you
the information you need to build an expansion board. It's to their

advantage in the end. One of the things that made the old AT bus
so popular was the wide variety of expansion cards for it.

Dave the DM
bank@lea.csc.ncsu.edu

ong@d.cs.okstate.edu (ONG ENG TENG) (01/19/91)

> In article <85TA02Rz04Ep01@JUTS.ccc.amdahl.com> jnb10@juts.ccc.amdahl.com (Joe Boucher) writes:
>>I am looking for as much technical info as I can get on Microchannel.
>>
>>I have a 55 SX and would like to build some interface boards. Is the
>>information itself licensed by IBM, or is it freely available as it is
>>with the AT bus? I can't seem to get an answer from IBM reps as to whether
>>or not the info is in the Technical Ref Manual.
>>
>>Does anyone have any suggestions for any books that might have complete
>>specs (enough to design from), or anywhere else that I might try.
>>
>>Thanks in advance.
>>Joe Boucher

The below is meant to stimulate more discussion on the *technical* facts
on the microchannel card, and not to actually provide them.
I heard that the number of chips needed to drive the microchannel
card takes up more than half the full-length card, leaving little space for
the circuit of whatever the card is originally supposed to do, 
especially since the card itself is so short (as opposed to tall).
Also, the card is so hard to design that even a longtime ISA motherboard 
designer/maker has to buy the design info from another microchannel
(serial port) card maker in order to implement their ISA card function
onto a microchannel card.  All in all, unless you are a 
near-million-dollar company/person, forget it!  Can anyone please
change my mind?

kirsch@ux.acs.umn.edu (Dave Kirsch) (01/20/91)

In article <1991Jan19.023553.23505@d.cs.okstate.edu> ong@d.cs.okstate.edu (ONG ENG TENG) writes:
>
>The below is meant to stimulate more discussion on the *technical* facts
>on the microchannel card, and not to actually provide them.
>I heard that the number of chips needed to drive the microchannel
>card takes up more than half the full-length card, leaving little space for
>the circuit of whatever the card is originally supposed to do, 
>especially since the card itself is so short (as opposed to tall).
>Also, the card is so hard to design that even a longtime ISA motherboard 
>designer/maker has to buy the design info from another microchannel
>(serial port) card maker in order to implement their ISA card function
>onto a microchannel card.  All in all, unless you are a 
>near-million-dollar company/person, forget it!  Can anyone please
>change my mind?

  I'd like to know where you 'heard' this? We've got a couple of boards that
are less than 1/2 length boards. We're running both a board for extra serial
ports and another for extra parallel ports in our server (an 80 A-31), and 
the population of chips on these boards is 'sparse' at best.

  As for designing MCA boards, why would a board designer need to buy the 
design from another board maker? Sure, they may want to consult another board
maker about design, little tricks, etc. However, there is no reason they 
should have to 'pay' anything to another board maker. The microchannel 
standard/specs have been 'opened up' by IBM to the extent that they are no 
longer charging licensing fees for MCA machines. IBM has (at least partially)
seen the error of their ways; it is now far easier to develop for the 
microchannel platform. (I'm sure that has more than a little to do with 
losing market share.) 

Dave Kirsch 
kirsch@ux.acs.umn.edu 

jgb@prism.gatech.EDU (James G. Baker) (01/21/91)

In article <1991Jan19.023553.23505@d.cs.okstate.edu> ong@d.cs.okstate.edu (ONG ENG TENG) writes:
>I heard that the number of chips needed to drive the microchannel
>card takes up more than half the full-length card, leaving little space for
>the circuit of whatever the card is originally supposed to do, 
>
>All in all, unless you are a near-million-dollar company/person, forget it!
>Can anyone please change my mind?

MCA is really not that difficult. I have made several cards for my PS/2 model
70.  Unless you have your own surface-mount LSI stuff, don't expect to make
an eithernet card on one of these boards, but you can do a lot with normal
parts.  Start with an MCA card with the address decode on it(Jameco,etc).  But
even in that case, the address decode only is about 1/7 the area. The POS
implementation is not bad either and has great flexibility.

I hope that this group will support more technical questions about the MCA 
specs, rather than only "Can I have 2 hard disks in my m30..."  




-- 
BAKER,JAMES G - Undergraduate Lab Instructor, School of Electrical Engineering
____  _    _    Georgia Institute of Technology, Atlanta Georgia, 30332
  |  | _  |_)   uucp: ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!jgb 
(_|. |_). |_).  Internet: jgb@prism.gatech.edu