ET(4) atari ET(4)
NAME
etdriver for ET4000 VME graphics cards
SYNOPSIS
et0 at vme0
DESCRIPTION
The et device driver supports VME graphics cards based on the Tseng ET4000 chipset. It supports the minimal ioctl's needed to run X11. The 8Kb control registers are mapped from offset 0x0 to offset 0x1fff and the 1MB frame buffer is mapped from offset 0x400000 to offset 0x4fffff. VGA compatible memory is mapped from offset 0xa0000 to offset 0xc0000.
HARDWARE
Cards supported by the et driver include:
 
Crazy Dots II VME graphics card
NOTES
The clock generator on the Crazy Dots card is an ICS 1394M. Setting the clock is done by writing to a register at offset 0x0. This address cannot be read. The values that can be written to the register and the associated clock are:
Value
Clock
0x00
14318
0x10
16257
0x17
20000
0x0c
24000
0x04
25175
0x14
28332
0x18
32514
0x1a
36000
0x1c
40000
0x03
44900
0x0f
50000
0x13
50344
0x07
56644
0x11
65028
0x1f
80000
FILES
/dev/etvme
AUTHORS
Julian Coleman
BUGS
The driver does not support a text mode, so cannot be used as a console.