HP 21MX/F and OS choices (was Lookee what I just got!)

[Jay West]

Steve wrote....
>I found that serial booting the system to be the easiest way to get 
>started. I don't recall which one but, one of the loader ROMS will work 
>with the "high speed serial" card and read data off a serial link.

I don't recall any loader rom working with a 12531 HS TERM board. I could 
well be wrong though, it's been WAY too long since I had my head firmly in 
HP-world. You CAN do it with a 264x (terminal) loader rom and a BACI board - 
as Bob S. said. If there is a loader rom that happens to work with the 12531 
(ie, if the 12531 happens to have the same programmatic interface as say... 
the paper tape board...) I'd like to know. I just don't have time to go test 
it :)

> There's no handshaking or error correction but, with a short RS232 link, 
> passing data is not a problem. The ABS data format does provide checksum 
> error detection so data errors will be detected.

Careful there... checksum (mod256) does NOT catch transposition of 
bytes/words, missing all zero words/bytes, extra all zero words/bytes, and 
identical bits swapped between words/bytes. There is a length field included 
in the ABS format so that will catch missing or extra nulls. But it still 
won't catch the other errors.

Jay