IBM 5150 PC

Fred Cisin cisin at
Wed Jul 15 11:51:23 CDT 2009

On Wed, 15 Jul 2009, Dave Dunfield wrote:
> Just curious - I don't know if I ever saw a Microsoft branded
> version of MASM 1.0 - I have the complete IBM "Macro Assembler
> by Microsoft" package, which is packaged in a pink PC format
> binder with about an inch thickness of paper - I've saw a lot
> of products in that era with much worse documentation.

Ahh, the days of mimeograph, or even ditto'd pages with a disk in a
zip-lock bag!

Although IBM sold it as a separate product, several OEMs just bundled it
with MS-DOS.

> The manual states that it's "First Edition (December 1981)
> and the MASM executable spits out:
> -----------------------------------------
> The IBM Personal Computer MACRO Assembler
> Version 1.00 (C)Copyright IBM Corp 1981
> -----------------------------------------
> Is this essentially the same assembler that is being discussed?


> There are two assemblers in the package, ASM which is without
> macros and requires 64k and MASM which does support macros and
> requires 96k - someone scoffed at this, but it seems reasonable
> to provide a limited version for a very small memory footprint
> system (many vendors did this in the days of limited memory).
> It does state that if you have 96k you can run either assembler,
> so I don't think it has anything to do with needing to architect
> if differently for different amounts of memory.

ASM also had more terse error messages than MASM.  No big deal with
experience, but frustrating for students.

> We used this package a lot in some early PC product development,
> and I do recall that it was slow and had a number of quirks, but

One real fun item was the avalanche of "Phase Errors" whenever you had a
type mismatch with a forward reference.

> we did produce a lot of working code with it. I also recall that
> when we upgraded to MASM 4 is was *much* better (in fact I still
> have it installed and use it from time to time).

Grumpy Ol' Fred     		cisin at

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