Setting up the Horizon Ramdisk

The Horizon Ramdisk 4000 can be emulated via MESS/MAME. This selection will emulate a two megabyte ramdisk which is actually saved in the "\nvram\ti99_4a" directory within a file.

Note: The directory is usually classified by the current machine type being emulated

The emulation will respond to the equivalent speed of the ram disk on actual hardware.

This process was created using MAME1076b 64bit and ROS version 8.32e.

Note: If using ROS 8.14f or earlier, sector sizes will be limited to 1600. ROS 8.32 allows for 3200 sectors per disk.

Procedure:

1> Boot into MAME and the TI-99/4A ROM
2> Bring up the MAME menu by pressing SCROLL LOCK then press TAB
3> Configure your System Devices for your wanted configuration. For this example I will be showing PEB Slot #5 as the Horizon RAMDISK.

4. Reset the machine for the settings to go into effect.

The default CRU address for the ramdisk is 1200. If there will be multiple HRD's then the CRU address will need to be changed for each additional HRD to a CRU that does not conflict with any other expansion card.

5. Bring up the MAME menu by pressing SCROLL LOCK then press TAB
6. Select Dip Switches

7. Select the Horizon ram disk slot
8. Select Horizon CRU base section and change the CRU appropriately
You will need to do this for each ramdisk within the system if you have more than one.

To change the CRU address for multiple cardsGoto