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New HP-41 module available: Ladybug
01-12-2017, 06:38 AM
Post: #20
RE: New HP-41 module available: Ladybug
(01-11-2017 08:16 PM)hth Wrote:  I assume you mean "JNC +00" goes to next line? I saw that in the CX ROM, often before an ENROM instruction. I do not really understand why, but suspect that they are there to avoid having a GOSUB go to that location and get trapped by the NOP means RTN feature, as ENROM really is a NOP variant.

But in the advantage it is done at the destination. Does it switch on the fly as well? Do you do the same in your banked modules?

First I meant "JNC +01"", not "00" - sorry for the typo. Both the CX and the advantage are similar in that the bank changes are not happening in the same page that issues the ENBANK instruction, so being "on the fly" is not an issue I suppose. Having said that the banking is managed by the module itself, so its behavior will be suited to the hardware it's running on - or so I thought. This is why the Zeproms manage to have FOCAL code in bank-switched pages, but this is not related to this case.

Second typo - those JNC +01 are not in the destination but right before the ENBANK instructions. Again, I thought this to be a whimsical note due to the hardware used. The HEPAX does *not* include those superfluous jumps ... so all this may off the point.
In my modules I use the HEPAX model, which ultimately also relies on a working "on the fly"model but all bank switches are made in the same routines, which are duplicated on each bank.

As I said it works just fine on V41. Will burn to a CL flash this week-end, but I don't expect any issues there either.

The PACKING issue is somehow bothersome - I guess this was one case not accounted for in the IO_POLL code? Hope you can patch it as well.
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New HP-41 module available: Ladybug - hth - 01-10-2017, 03:12 AM
RE: New HP-41 module available: Ladybug - Ángel Martin - 01-12-2017 06:38 AM



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