Hi Gordon,
I have an addendum page (in french) for the HP-IL manual with bug workarounds for the 1A version.
Here is a sort summary (translated by myself, sorry ...):
1 - ENTER: if an under/overflow can occur during numeric input, then use an alpha variable and use
the VAL function, OR make sure that flag -1 is clear and don't place other variables after the numeric variable.
e.g. replace
ENTER 2;A,B
with
ENTER 2;A$,B$
A=VAL(A$) @ B=VAL(B$)
or
F=FLAG(-1,0)
ENTER 2;A
ENTER 2;B
F=FLAG(-1,F)
2 - OUTPUT and PRINTER IS: Avoid risk of Memory Lost during OUTPUT and PRINT by using one of these actions:
* use ENDLINE to define the end-of-line sequence with zero or three characters,
* or use OUTPUT and PRINT instructions that don't send end of line sequence (end the instructions with ';')
and define an infinite width for PRINT
3 - CAT and CAT$: avoid Memory Lost condition during CAT operations by using one of these actions:
* don't press any key when the mass storage is busy (LED on)
* or make sure that the first file is not deleted (immediatly PACK if you delete the first file)
4 - PACK and PACKDIR: avoid Memory Lost condition during packing of a medium by NOT using a user
defined function in the unit identifier.
Bugs 2 and 3 were the most serious ones.
I remember that in these old good days I always used a 3-character end-of-line sequence: ENDLINE CHR$(13)&CHR$(13)&CHR$(10) (bug 2).
It was also a good practice to create a dummy first file just after disc initialisation to protect against bug 3.
Regards.
J-F