Geneve drive remapping

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REMAP allows a disk I/O device to be mapped to any DSK1...DSK9 device number. Usage is as follows either in an AUTOEXEC file or at the MDOS prompt.

REMAP <number><DRIVE>
A Floppy #1 Any floppy-only controller
B Floppy #2 Any floppy-only controller
C Floppy #3 Any floppy-only controller
D Floppy #4 Any floppy-only controller that supports 4 floppies
E Internal Geneve Ramdisk
F Internal Horizon Ramdisk 8 bit CRU >1400 256K
G Internal Horizon Ramdisk 8 bit CRU >1600 256K
H Internal Rave Ramdisk
I HFDC Emulate File
J HFDC Floppy #1
K HFDC Floppy #2
L HFDC Floppy #3
M HFDC Floppy #4
N Internal Horizon Ramdisk 16 bit CRU >1400
O Internal Horizon Ramdisk 16 bit CRU >1600
P Internal Horizon Ramdisk 16 bit CRU >1000
Q Internal Horizon Ramdisk 16 bit CRU >1700
R Internal Horizon Ramdisk 16 bit CRU >1800
S Internal Horizon Ramdisk 16 bit CRU >1900
T PFM FlashDisk #1
U Reserved for PFM #2
V Reserved for Future Expansion


REMAP 1W       Maps DSK1 to TIPI DSK1 (assumes PI.CONFIG has entry)
REMAP 4Q       Maps DSK4 to a 16 bit HRD at CRU >1700

(taken from the GeneveOS 7.30 manual)


The SCSMAP command allows the use of SCS1 through SCS6 for devices.

SCSMAP also allows mapping the IDE drives to a SCS device name as

SCSMAP <x><y>

x is the number of the SCSx device in GeneveOS, ranging from 1 to 6 (for SCS1 to SCS6).

y is the physical device as shown in the following table.

Drive assignment Device
0 SCSI Device ID 0
1 SCSI Device ID 1
2 SCSI Device ID 2
3 SCSI Device ID 3
4 SCSI Device ID 4
5 SCSI Device ID 5
6 SCSI Device ID 6
7 SCSI Device ID 7 (controller)
8 HRD CRU >1400 ramdisk
9 HRD CRU >1600 ramdisk
A IDE Device #1
B IDE Device #2
C IDE Device #3
D IDE Device #4
E IDE Device #5
F IDE Device #6
G IDE Device #7
H IDE Device #8

Special note for IDE partitions

Using Fred Kaal's DSR on the IDE adapter card, you can partition your IDE drive into up to four partitions. Also, you can use two IDE drives, which should provide you with up to 8 partitions.

As of 3 April 2021, testing of the IDE support in MAME has shown a potential issue of being unable to use IDE Device #8 if a user has partitioned both drives into 4 partitions each. This is unrelated to GeneveOS as it has been confirmed in the TI-99/4A emulation as well within MAME. The developer of the DSR has been contacted for investigation.

Fred Kaal's DSR is available at, Version 14 ("Projects" -> "Ide Dsr").

The SCSMAP also allows mapping 16-bit Horizon Ramdisks into the SCSx "RamHardDrive" addressing. See identifiers below.

Please note, SCSI and IDE have more devices than the SCSMAP will presently allow. Plan drive size and mapping accordingly to maximize your equipment configuration.

Default drive mappings

  • SCSMAP 11: Device ID 1 to SCS1
  • SCSMAP 22: Device ID 2 to SCS2
  • SCSMAP 33: Device ID 3 to SCS3
  • SCSMAP 48: HRD Ramdrive CRU >1400 to SCS4
  • SCSMAP 59: HRD Ramdrive CRU >1600 to SCS5
  • SCSMAP 6A: IDE 1st Drive, 1st Partition to SCS6

More examples

As an example, SCS1 may be reconfigured as follows:

  • SCSMAP 10: Device ID 0 as SCS1
  • SCSMAP 16: Device ID 6 as SCS1

IDE drives and the Horizon Ramdisk - when configured as a RAM Harddrive - are also mapped as a SCSI device as follows:

  • SCSMAP 48: Horizon Ramdisk at CRU >1400 as SCS4
  • SCSMAP 39: Horizon Ramdisk at CRU >1600 as SCS3
  • SCSMAP 3A: IDE Device #1 as SCS3
  • SCSMAP 6H: IDE Device #8 as SCS6

There is one special case: Device 7 is treated as Device A, that is, IDE Device #1. Hence, SCSMAP 37 has the same effect as SCSMAP 3A.

(taken from the GeneveOS 7.30 manual)

MAME usage notes

If you want to use the WHTech SCSI controller emulation in MAME, you have to define the SCSI ID number for the hard drive. Suppose you want to assign SCSI ID 0 for the harddisk:

for the TI-99/4A (with or without EVPC):

mame ti99_4a ... -ioport:peb:slot7 whtscsi -ioport:peb:slot7:whtscsi:scsibus:0 harddisk -hard1 myscsidisk.hd

for the Geneve, Genmod, and SGCPU:

mame geneve ... -peb:slot7 whtscsi -peb:slot7:whtscsi:scsibus:0 harddisk -hard1 myscsidisk.hd

So you have to specify the kind of device that is connected to the SCSI bus at the given number (:0 for ID 0). If unspecified, nothing is connected. The SCSI controller chip is always hooked to ID 7 (even though you can select it on the real card).

When you define "harddisk" to be connected to SCSI bus IDs, the "hardX" entries are allocated one after another to these IDs in ascending order.

If you have a second card or you have a HFDC in the next slot, it will take the remaining drives. So if the SCSI card is on slot 7, uses one harddisk, and HFDC is in slot 8 with one MFM hard disk, the image "-hard1" will be linked to "SCS1", while the image "-hard2" will be "HDS1".