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Computer specific configurations

FreddyV edited this page Sep 23, 2024 · 16 revisions

How to use the PicoMEM with existing HDD ?

!! Use the PicoMEM with an existing HDD was tested on few machines, this may not work yet.

With a Legacy HDD (XTA, Filecard, IDE):

When an existing Legacy HDD is present, it will be put as HDD0.
If you want to add a PicoMEM disk image, place it as HDD1.
In the recent firmware, you can replace HDD0 with an image, but the existing disk will no more be accessible.

For Firmware <= 28 June :
The PicoMEM Will boot only on the HDD0 and HDD0 is always the existing disk.
Then, if the computer disk is not bootable, it is not possible to Boot the machine on a disk.

With an XTIDE:

You need to place the XTIDE BIOS (ROM Address) Before the PicoMEM BIOS.
Then, it is recommended to place the XTIDE at C800 and the PicoMEM at D000.
You can only Boot on the PicoMEM Disk as the XTIDE will place its Disk after the PicoMEM ones.
Note : It may crash if you use more than 1 emulated disk
You also need to disable the "Use PicoMEM Boot code" to allow the XTIDE to Start.

Other important point:

XT Hard drive often use the DMA. It is then not possible to use the PicoMEM with these disk and emulated RAM in this case.

How to use the PicoMEM with the Book8088 ?

To allow the PicoMEM to Start, the PicoMEM BIOS setup must start before the XTIDE BIOS
To do this, a special configuration was designed :
Add PREBOOT in the config.txt file in the uSD home directory. (Not implemented in April 24 Firmware)
It is recommended to add BIOS C800 to place the PicoMEM BIOS at the begining of the extension ROM Address Space.
A Book8088 config.txt example file is placed in the GitHub firmware directory

EMS : Select the port 388, default port (368) will not work.

For a Book8088 with VGA :
Enable the option "Exclude Video RAM* in the RAM emulation menu.

Note for the 8MHz Mode:

  • It is not stable in Battery mode only, you must plug an external power.
  • EMS Does not work.
  • As the ISA timings are not standard in this mode, it is not guaranteed to work on all the Book8088.

Commodore PC10 / PC20

The PicoMEM is tested successfully on my Commodore PC10-2.
Anyway, the EMS and PSRAM emulated RAM Does not work, only the PMRAM RAM Emulation (With the pico memory) is working.

On some PC10, it work only in "Turbo" or "Double" Speed mode (Ctrl Alt+D or +T)
New: You can also test the Fast RAM Mode firmware. (_FR)

Monotech NuXT Computer

Don't forget to disable the Upper memory zone where the PicoMEM BIOS is placed. (See the Issue #13)
(https://github.com/monotech/NuXT/)

IBM 5150

Early verion of the IBM 5150 does not support optional ROM.
Then, PicoMEM (Or Even XTIDE) will not work work with it.

Minimal version : 10/27/82

References:
https://www.minuszerodegrees.net/5150/bios/5150_bios_revisions.htm
https://www.minuszerodegrees.net/5150/motherboard/5150_u33.htm

Amstrad PPC640 / PPC512

Somebody recntly solved Boot issue by changing one capacitor on the ISA extention Board. IF it can help someone else, here is the link: https://github.com/FreddyVRetro/ISA-PicoMEM/issues/53

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