HP 87: PLOT ROM B 00087-60929

[J-F Garnier]

(06-14-2018 12:52 PM)Michael Fehlhammer Wrote:  I am not so familiar with the series 80; what is the quickest way to compare the contents? Can you provide instructions? I have got the assembler rom, maybe that helps.

With the MEM command of the assembler ROM, you can have a look at the content of the ROM, and maybe check if it's a different version.
Do MEM 60000:360 [ 60000 is the (octal) address of the beginning of the plugged-in ROM area and 360 is the octal id of the plotter ROM]
You should get something like (the first two bytes identify the ROM):
360 020 012 140 360 140 174 140 p `p`|`
077 141 247 141 000 000 000 000 ?a'a
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000

Now, if you do
MEM 77700:360
you can check the last bytes of the ROM, that are probably kind of checksum bytes. Here is what is in the standard plotter ROM (checked in the excellent HP80 series emulator from Everett Kaser):
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 000 000 000 000
000 000 000 000 130 224 326 250 X V(

J-F