NAME

ibm5154, ega − IBM 5154 Enhanced Graphics Display interface

SYNOPSIS

pseudo-device ega

DESCRIPTION

The ega is a standard IBM Personal Computer AT Enhanced Graphics Display and display adapter.  The display adapter is accessed through a memory-mapped I/O address space.  The display buffer is at address 0xf40b8000.  Opening /dev/ega grants direct access to the display buffer and the monochrome registers in the I/O map if bit 0x8 is set in the minor device number.  The registers are at the addresses given in Volume II of the IBM RT PC Technical Reference Manual, offset by 0xf0000000. 

Each character on the display has two bytes in the buffer; one contains the character, the other the attributes.  The attributes available are eight independently selectable colors for foreground and background, blink mode, and intense mode.  There is no underline mode for the ega.  These are available through escape sequences sent to the display (see ibmemul(4)). All other functions are provided through software terminal emulation, including either 24-line (plus status) mode or 25-line mode, forward and reverse scrolling and cursor positioning.

The display is normally controlled by ibmemul, and accessed as /dev/ttyega. (See cons(4)). It may also be opened and manipulated as /dev/ega and /dev/bus for nonstandard use.  The default color table for the ega color table is:

0black
1blue
2green
3cyan
4red
5violet
6yellow
7white

The ega has eight color table entries which can select from a palette of eight colors. 

NOTES

Ibm5154 is not supported on the IBM 6152 Academic System. 

DIAGNOSTICS

None. 

FILES

/dev/console
/dev/ttyega
/dev/ega

SEE ALSO

bus(4), cons(4), ibm5151(4), ibm6153(4), ibm6154(4), ibm6155(4), ibmaed(4), ibmemul(4), kbdemul(4), tty(4)
“IBM/4.3 Console Emulators” in Volume II, Supplementary Documents

BUGS

Access to the PC/AT I/O and memory busses through /dev/ega, when bit 0x8 is set in the minor device number, is not limited to the mono and ega addresses. 

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  Sept 1988