Closed Dudejo closed 6 months ago
Ths means it must have some sort of proprietary EMS chipset, because with the top 384k reserved for ROM space, I doubt you can directly address 1024k of RAM using just the CPU.
It appears to be this: https://theretroweb.com/chipsets/943. Which means this is a CANTFIX, since the chipset has no datasheet.
After a little "investigation" I've found these info: TAMCS00001-1.pdf The PC supports 1MB RAM but the 384KB are for RAM Disk only Drivers are here: JUKO.zip The file CDISK.SYS creates a 384KB RAM Disk
The drivers you provided don't work.
It seems not having the full 1024 kb in POST, like my initial screenshot shows, is causing issues.
is there a way to override the built-in 86Box RAM limits to test 1024kb of RAM?
I have these same drivers, one for a RAM drive, disk cache, and other for print spooler. But the 8088/8086 CPUs can only "see" 640kb of RAM unless the extra hardware chip is emulated. The 808x and 286 cannot map upper memory RAM in real mode without extra hardware. Some 286 can map it as XMS. But EMS, UMB or other type of management requires extra hard ware. The 386 uses the V86 mode to map some of the XMS RAM as EMS and/or UMB.
"But the 8088/8086 CPUs can only "see" 640kb of RAM unless the extra hardware chip is emulated."
EMU386 can solve this issue, if using a real, or emulating, NEC V20/V30 or better (I suggest a NEC D9008D FPU also, both at 16mhz if possible if you have a NEC V30HL). I'm running the kernel updated New Deal Office 2000 (https://archive.org/details/geos_20240815) I can confirm AMAZING RESULTS (full 1mb conventional ram access, plus a PicoMEM 5mb EMS Card = 6mb ram!)
What happened?
The 8088 Juko ST is supposed to be able to record up to 1024 kb of RAM during POST. However, 86Box's emulated board can't be configured beyond 640 kb. This prevents the use of a proprietary RAMDrive device and potentially other Juko programs as well.
This screenshot was taken from a YouTube video showing off the Juko ST's 1024 kb during POST :
Configuration file
Operating system
Windows 11
CPU
Intel i3 13100F
86Box version
build 5671
Build architecture
Windows - x64 (64-bit)
Build type
Download source
Official website (Jenkins, GitHub)
Additional context
No response