[TUHS] Bell Labs CSTRs

Dan Cross crossd at gmail.com
Sun Jul 2 03:28:00 AEST 2023

On Thu, Jun 29, 2023 at 11:05 AM Will Senn <will.senn at gmail.com> wrote:
> Clem's +1 caught my attention, so I looked into the referenced docs. I saw the rather simple (conceptually) m6 processor described in tech note 54. I like its understandable.
> Why is it called m6? Just curious.

I'll take a stab at that; I presume it's due to the naming convention
for macro processors from Bell Labs. Consider m4, which itself was
written as, "an extension of a macro processor called M3 which was
written by D. M. Ritchie for the AP-3 minicomputer; M3 was in turn
based on a macro processor implemented for [1]." (from, "The M4 Macro
Processor" by Brian Kernighan and Dennis Ritchie, as distributed with
4.3BSD; reference [1] is to "Software Tools" by Kernighan and

Anyway, once you've got M3 and M4, you've got a naming convention; I'd
think it a safe bet that there was an M5 that was an internal
experiment, and that M6 was simply the next in line and was
interesting enough to be documented in a tech report.

        - Dan C.

Aside: the AP-3 minicomputer came up on this list a few years ago,
when Dag Spicer of the Computer History Museum was looking for
information about it. Near as folks could figure, it was the computer
portion of a Bendix "stereoplotter" for creating terrain maps and the
like (Adam Sampson figured that part out; others derived Bendix from
part numbers taken from a US Air Force spare parts requisition
document I found).

> On 6/29/23 09:40, Clem Cole wrote:
> +1 👍
> On Thu, Jun 29, 2023 at 3:37 AM Noel Hunt <noel.hunt at gmail.com> wrote:
>> Many thanks.
>> On Thu, 29 Jun 2023 at 17:14, <arnold at skeeve.com> wrote:
>> >
>> > Available at https://www.skeeve.com/bell-labs-cstrs.tar.gz
>> >
>> > Warren and Brantley and anyone else, feel free to retrieve.
>> >
>> > I have two sets - both are in the tarball so there are undoubtedly
>> > duplications.  If someone else can curate them into single canonical
>> > set that'd be helpful, I just don't have the time right now.
>> >
>> > Enjoy,
>> >
>> > Arnold

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