Am 07.06.2015 um 05:40 schrieb J. David Bryan:
On Saturday, June 6, 2015 at 21:44, Cory Smelosky wrote:It seems there's no current SIMH support for the HP 1000 A-series system (A900, A990, A600 et cetera) meaning RTE-A (with the ARPA/1000 software!) is unfortunately out.That's correct.Looks like enough docs for at least some of the later ones are up on Bitsavers...any plans for implementing these missing models?Holger Veit <[email protected]> had been looking into doing a SIMH A-Series simulator several years ago, but I've not heard what progress he made, if any. Regrettably, relatively little of the existing HP 1000 M/E/F-Series simulator could be leveraged for an A-Series simulator. The base set instructions are the same, although the I/O instructions and I/O structure are entirely different, and there are a number of new instructions. Also, essentially none of the M/E/F peripherals (disc, tape, terminal multiplexers, line printers) were supported on the A-Series, so a whole new set of peripheral simulators would have to be written. An off-the-cuff guess would be that reusing the base set would cover maybe 20% of the full simulator code. The other 80% would have to be written from scratch. On the plus side, the full RTE-A sources, the A-Series microcode, and several RTE-A binary releases are available in the HP 1000 Software Collection on Bitsavers, so the job is by no means impossible.
JDB summarizes the problem quite precisely.After the microcode ROM stuff, JDB and I added to the HP1000 system, I infact looked at the A series, to possibly extend the simulator with "the missing A instructions". It turned out that the A series is not only a class of quite different systems with entirely different properties but also with a completely new I/O system (based on a monolithic chip). It is a new platform. Workload prevented me from following this further, but I am still attracted by such a simulator, mainly because of the microcode which is well documented for some of the models, as well as for RTE-A itself which is a technological progress to the older RTE-IV/6VM systems.
On the documentation side, the I/O chip is well documented, however the various peripherals that are built around it are less described. That time I didn't find a complete enough set to combine a useful A hardware. The CPU part itself is likely the smallest problem even if I'd start this from scratch as well (as a plain microcode interpreter) rather than
lifing the base instructions from the HP1000 emulator.The things are not forgotten, as well as the PDQ3 and Sage-II/IV things - it's just the general problem that the day is
limited to 24h. -- Holger
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