github.com/rdolbeau.VintageBusFPGA_Common
1
0
Fork 0
mirror of https://github.com/rdolbeau/VintageBusFPGA_Common.git synced 2026-04-10 06:26:56 +00:00
Code Issues Packages Projects Releases Wiki Activity

readme for sun 3/160 memory

Browse Source
This commit is contained in:
Romain Dolbeau
2025-06-28 08:18:52 +02:00
parent 0a07b18626
commit 0773a6d82a
1 changed files with 10 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
RomPatcher/Sun3_160MaxMemory/README.md Normal file
View File

@@ -0,0 +1,10 @@
# 3/160 expanded memory ROM patch
This small patch enables the Sun 3/160 memory to recongnize more than 32 MiB of RAM (only tested in TME, The Machine Emulator)
* "replace1" patches the upper bound of the memory-sizing loop
* "replace2" patches an assumption at one point in the ROM that only 32 MiB is installed. The original test is to check for >=32 MiB and if so, subtract 128 KiB. This replaces the subtraction with a hardwired (32MiB - 128 KiB) value.
The combinations of both patches is enough that 128 MiB of memory can be specified in the TME config file:
`ram0 at obmem0 addr 0x0: tme/host/posix/memory ram 128MB`
And both the ROM and NetBSD (tested 9.0) will recognize 128 MiB.