In message <AANLkTi=Z8oX4dQWY_nRQDcnkMDHZRRc3QhsaB0=7_...@mail.gmail.com>, paul swed writes:
>Though only 8K of eprom I suspect its cleverly coded. It's not really that bad. There has clearly been somebody there to pound structure into the result, and there is very little evidence of code-bumming. >So its quite speedy and does also have interrupt capability. At a cost of >$3-4 each its nothing to use several for different apps like the front panel >display and keys, control for actual counting and finally a third for >ethernet or GPIB. (Maybe I will get to that one day) Well, all the existing I/O shares the same 16A8D databus, and there is hardly anything gained from having multiple processors fight for that bus. The I/O is also very much built to reduce CPU work, the display/leds are self refreshing, the GPIB has its own ROM based state-machine etc. >But really the key to any of this would be the accurate decoding of the >existing software. I have 303 bytes undecoded right now, 256 of these is a table which I suspect is related to floating point squareroots, and a fair number of the rest are padding. As I said it is quite structured. It is a total no-brainer if you executed it by emulating a M6800, and only intercepted a few places to add features. >Though HP service docs are somewhat useful in this approach for the 5370 >vintage. At least you tend to be able to understand what IO does what. The HP5370B is actually very good in that respect, I have been able to figure out all the I/O that way. >For me since the 3 5370s are working, I won't be hacking them anytime soon. >Like'em the way they are. Now, that's the other part: It is a very good instrument. The only feature I have been able to dream up yet is a digital clock, and only because that is sort of the default for anything with a display. But it could be interesting to see what the hardware can do with sufficient CPU resouces, because right now it is clearly CPU-limited. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.