Best way to init SP (ROM)?

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By gdx

Enlighted (4160)

gdx's picture

24-07-2020, 17:04

Forget what I just wrote, I wrong.

By theNestruo

Champion (273)

theNestruo's picture

24-07-2020, 17:08

I'm pretty sure OP's question was about ROMs using BIOS.

In this old thread about Zombie Incident, nenefranz states that ld sp,$F380 was causing issues with the Sony HB-F500, and ld sp,(HIMEM) fixed those issues.

By sd_snatcher

Prophet (3435)

sd_snatcher's picture

24-07-2020, 18:56

I remember that I had issues with ld sp,(HIMEM) too, so these days I use a fixed conservative ld sp,0xE000

If the stack can't be placed that low for whatever reason, it means that the system doesn't have enough free memory to run the software.

By Grauw

Ascended (9666)

Grauw's picture

24-07-2020, 19:06

Do you remember what kind of issues? Was it that HIMEM was lower than E000H?

By hit9918

Prophet (2899)

hit9918's picture

24-07-2020, 22:19

SjaaQ wrote:

I have a 256 byte table to deal with the databus problem (ok 256 bytes wasted). It contains something like #C1 for every byte so the pointer to the address will always be #C1C1.

but you need 257 byte. like for example from D800 to D900. because when the low byte is at D8FF, who knows, it does a 16bit increment to get the high byte, and then it reads D900.

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