HP82143 Processor details

[brouhaha]

(09-19-2023 07:51 PM)blackjetrock Wrote:  The data is attached in the interests of preservation. The end of the dump repeats the same data pattern, this may be a dumper problem or it may be that the data wraps after the end of the ROM, I'm not sure.

Thanks for doing that, Andrew!

The fact that your text file contains two dumps, which have some similarities but in general are significantly different, is rather disconcerting.

A normal MK3870 (without a /nn suffix) has 2KiB of ROM (earlier in the thread I mistakenly said 1KiB), so I would expect addresses 800 and up to either be empty (probably 00 or ff), or repeats of the data at 00. It's remotely possible that this is actually a 4K ROM 3870, in which case the empty area or wraparound would occur after FFF.

The original MK3870 with no numeric suffix has only an 11-bit program counter. The numeric suffixes /10, /20, /30, and /40 have 1K, 2K, 3K, and 4K of ROM respectively, but all three of those have a 12-bit program counter, so the /10 is compatible wth the no suffix except under contrived circumstances. The /12, /22, /32, and /42 versions are the same except that the last 64 bits of the ROM address space contain RAM. (That means that the /42 doesn't really have 4K of ROM.)

You might try dumping the Boris 3870 a few more times, and see whether you get consistent data between multiple reads.