MIX and MIXAL at UCSB
A UCSB student reports a MIXAL assembler in SNOBOL4 and a partly debugged MIX simulator.
Pickens, J.R., "MIX and MIXAL at UCSB", RFC 485, DOI 10.17487/RFC0485, March 1973, <https://www.rfc-editor.org/info/rfc485>.
@misc{rfc485,
series = {Request for Comments},
number = 485,
howpublished = {RFC 485},
publisher = {RFC Editor},
doi = {10.17487/RFC0485},
url = {https://www.rfc-editor.org/info/rfc485},
author = {J.R. Pickens},
title = {{MIX and MIXAL at UCSB}},
pagetotal = 1,
year = 1973,
month = mar,
} RFC text
Network Working Group John R. Pickens
RFC # 485 UCSB
NIC # 15063 19 March 1973
References NWG/RFC #473
MIX and MIXAL at UCSB
The following, in response to David Walden's MIX query (RFC#473) was
written by a graduate student at UCSB. Questions regarding "cheap"
usage should be directed to Roland F. Bryan (RFB) at UCSB.
-----------------------------------------------------------------------
Mark Scott Johnson
18 March 1973
I wrote a MIXAL assembler and a MIX simulator last summer. The
assembler is written in SNOBOL4 and, unfortunately, is fairly expensive
to run. The assembler has been fairly well debugged and is documented.
However, although the MIX simulator is written (in 360 Assembler), it
has only been partially debugged. Due to the resumption of school and
other commitments, I was unable to give the simulator a thorough
debugging. All the simulated instructions except I/O instructions have
been tested somewhat and appear to be operating well. Also, card reader
input and printer output are operational, but my simulation of disk
files and magnetic tape has not been completed. There is presently no
documentation for the simulator. Very little documentation is needed,
however, since the simulator follows almost to the letter the
specifications detailed in _Fundamental_Algorithms_.
If anyone is interested in using the assembler and/or the simulator,
I will be happy to supply what documentation exists plus some
information on how the programs can be accessed. Also, if anyone is
interested in the source code for the programs, I will be happy to send
it. I hope to be able to finish the simulator this next quarter. If
anyone wants to use the system and if they should find any bugs, I will
do my best to maintain and correct the programs.
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On this page
§1A Reply to the MIX Query
The RFC passes on a reply, written by a graduate student at UCSB, to David Walden's MIX query in RFC 473. Questions about "cheap" usage were to go to Roland F. Bryan at UCSB. The reply is dated March 18, 1973 and signed Mark Scott Johnson.
A student answered a question from the network, and his teacher passed the answer on.
§2The Assembler and the Simulator
Johnson wrote a MIXAL assembler and a MIX simulator the previous summer. The assembler is written in SNOBOL4, fairly well debugged and documented, but fairly expensive to run.
The simulator is written in 360 Assembler and only partially debugged. All instructions except I/O have been tested somewhat. Card reader input and printer output work, but disk files and magnetic tape simulation are not complete. It has no documentation, since it follows almost to the letter the specifications in Fundamental Algorithms.
One program is nearly done but costs a lot to run. The other works for most things but is missing a few parts and has no instructions.
§3Offer of Help
Johnson offers to supply existing documentation, information on how to access the programs, and the source code. He hopes to finish the simulator the next quarter and says he will do his best to maintain and correct the programs if bugs are found.
He says he will share the programs and try to fix any problems people find.