EXP2 Delay Register Read-back

Writes the expansion region 2 delay/size register with four values and reads each back.

Overview

The program writes the EXP2 delay/size register at 1F80101Ch, the register for expansion region 2 (DEV8), with four values and reads each back twice. It then puts back the value the register held on entry.¹

Results

The register held 00080777h on entry. Each value written read back unchanged on both reads: 00070777h, 00080777h, 00000777h and 00010777h, so bits 16 to 19 of the register keep any value written. The register read 00080777h again after it was put back.¹

Runs

22 October 2026 link-2

Raw output: DEV8READBACK.txt · bench.txt

DEV8READBACK.txt:

D8RB entry=00080777
D8RB wrote=00070777 read=00070777 00070777
D8RB wrote=00080777 read=00080777 00080777
D8RB wrote=00000777 read=00000777 00000777
D8RB wrote=00010777 read=00010777 00010777
D8RB-DONE restored=00080777
ResetGraph:jtb=801e78b8,env=801e7900

bench.txt:

257 bytes of TTY text in psx.log

References