IBMAED(4) —

NAME

ibmaed, aed − IBM Academic Information Systems experimental display interface

SYNOPSIS

pseudo-device aed

DESCRIPTION

The IBM Academic Information Systems experimental display is a monochrome, all-points-addressable, bit-mapped display with 819,200 points on the screen. It is driven by an adapter with an on-board processor. The processor executes a microprogram loaded by the host into the display’s control store. The microprogram controls the interface between host and display. The host communicates with the microprogram through an area of read/write shared RAM. This memory starts at address 0xf40a4000 and is organized as 4k of 8-bit bytes.

The display operates as /dev/ttyaed in glass tty mode (the default) and /dev/aed in window-manager mode:

-During glass tty mode initialization, the display driver loads the control store with a default microprogram which includes a built-in font. This is followed by a cursor home and screen clear. In glass tty mode, the display driver emulates a smart terminal, similar to an IBM 3101, and can be /dev/console.

-In window-manager mode, a user-level process, such as a window manager, can load its own microprogram into the display’s control store, and read or write to the display’s communications memory. When a process opens /dev/aed, output intended for /dev/ttyaed is buffered by the kernel until later (see bufemul(4)). The process must then open /dev/bus to access the control store and communications memory areas when bit 0x8 is not set in the minor device number. Glass tty mode is reentered when /dev/aed is closed.

In glass tty mode, the aed microcode will interpret certain escape sequences to control display behavior. The recognized escape sequences are listed below. <Esc> indicates the escape character 0x1b. Home refers to the cursor position in the upper left corner of the display. The notation (n excess 0x20) means character n will be used as a binary value less 0x20. For example, to encode a binary 4, add 0x20. The ASCII character 0x24 is ’$’.

<Esc>0Begin/end stand-out mode. Characters are displayed in reversed color.

<Esc>1Begin/end underline mode. Characters are displayed as underlined.

<Esc>2Begin/end bold mode. Characters are displayed as bold (thicker than normal).

<Esc>3Begin/end special mode. Enables direct access to the status line, and makes it the last line of the screen. While in special mode, a delete-to-end-of-line or delete-to-end-of-screen will replace deleted characters with blanks having the current attributes (underlined, reversed). Placing a character in the lower-right corner will cause a wrap to upper-left corner instead of a scrolling action. This mode provides specialized support to the display driver, and is not intended for normal use. Ending special mode restores normal operation.

<Esc>4nStatus line processing. Beginning in column (n excess 0x20), write characters to the status line. Status line processing stops when the right margin is reached or when a null character (binary 0x00), <Esc>@, or carriage return is encountered.

<Esc>8nRetrieve the contents of display line (n excess 0x20). The character string is stored beginning at host memory location 0xf40a4100. Character attributes are stored at location 0xf40a4180.

<Esc>9ftdCopy lines from (f excess 0x20) through (t excess 0x20) to the destination area (d excess 0x20). Overlapping copy is not prevented. The order in which from and to occur controls the direction of the copy. If from has a larger value than to, the destination line will be at the bottom of the copied image. This function is provided in support of the special mode (see above), but may be used independently.

<Esc>AMove the cursor up one line (up-arrow).

<Esc>BMove the cursor down one line (down-arrow).

<Esc>CMove the cursor right one character (right-arrow).

<Esc>DMove the cursor left one character (left-arrow).

<Esc>EErase the status line.

<Esc>HMove the cursor to home.

<Esc>IDelete from current position to end of current line.

<Esc>JDelete from current position to end of display (bottom-right corner). The status line is left intact.

<Esc>KMove the cursor to home and erase the display.

<Esc>LMove the cursor to home and erase the display.

<Esc>NInsert a line below the current one. Scroll the remaining display lines down.

<Esc>ODelete the current line. Scroll the remaining display lines up.

<Esc>PcInsert character c at the current position. Shift the remaining characters on the current line to the right.

<Esc>SReverse the display color (background and characters).

<Esc>TcChange the hardware tab setting to (c excess 0x30). Acceptable values are binary 0x1 through 0x9, represented by the characters ‘1’ through ‘9’. When microcode is reloaded, the value is initialized to 8.

<Esc>QDelete the character at the current position. Shift the remaining characters on the current line to the left.

<Esc>YrcPosition the cursor at row (r excess 0x20), column (c excess 0x20).

<Esc>@Terminate status line.

A few of these sequences are useful for entry from the keyboard, including begin/end standout mode, begin/end underline mode, begin/end bold mode, and reverse display color. For example, if the display is accidently left in standout mode, the user may correct it by entering echo "<Esc>0".

The aed may also use ibmemul(4), in which case the above escape sequences would be replaced by the ibmemul escape codes.

A convenient way to reset all modes (especially useful if the display has become confused by trying to print a binary file) is to enter echo > /dev/aed.

As stated above, opening /dev/aed and /dev/bus will buffer glass tty output and gain access to the display hardware addresses. However, if the output emulator is changed to the aed emulator, support will be available for normal device system calls. See aedemul(4).

NOTES

Ibmaed is not supported on the IBM 6152 Academic System.

FILES

/dev/console
/dev/aed
/dev/ttyaed

BUGS

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

PRPQs 5799-WZQ/5799-PFF: IBM/4.3 — Dec 1987

Museum

Related Articles