Image Adapter/A

@8DF0.ADF IBM Image Adapter/A
@8DF1.ADF IBM Image/A and Printer/Scanner Option
@8DF2.ADF DSS and sub card 2
@8DF3.ADF DSS and sub card 3
@8DF4.ADF IBM Image Adapter/A 3MB
@8DF5.ADF IBM Image/A with Printer/Scanner Option

imageopt.exe PS/2 Image Adapter/A options diskette, version 1.04
   Ver 1.02 + correct Arbitration conflict, 1.03 corrects OS/2 2.1 install
iaopt211.exe Image/A & Image-I Opt Dsk (incl 76/77)
   Combined I/A and I-I/A, no idea of version, probably later than 1.04?

BIOS version 3.00 14-06-90 ST M27C256B-15 45F3367
   The last version seems to be 14/04/92. Unsure if there is a relationship between PCBs?

189-037 IBM PS/2 Image Adapter/A and Related Features
190-108 Image Adapter/A 1MB, 3MB and 3MB 6091

S71G-3708 IBM PS/2 Image / Image-I Adapter/A Technical Reference, 71G3708
S15F-2240 Image Adapter/A Hardware Maintenance Library ('90), 15F2240
S15F-2162 Image Adapter/A Technical Reference ('90), 15F2162

COMPEURO 89 Proceedings VLSI and Computer Peripherals.
   May 8 1989 to May 12 1989 Hamburg, West Germany
The IBM Image Adapter/A by R.J. Bowater
A VLSI display controller and processor by Adrian Gay
A 1-micron CMOS 128 MHz video Serialiser, palette, and DAC chip by Martin J Chesters
The VLSI 'silicon compiler' design process by R.M.P. West

ia32v211.exe Image/A & Image-I OS/2 Driver (2.1x-BETA)
iadsp211.exe Image/A & Image-I Display Sprt. (required)
ia16v210.exe Image/A & Image-I OS/2 16-bit drivers
iaopt211.exe Image/A & Image-I Opt Dsk (incl 76/77)
iawin210.exe Image/A & Image-I Windows 3.x drivers
iados210.exe Image/A & Image-I DOS AI & AutoCAD drivers

Image Adapter/A
   Image Adapter/A DCP and DSC Functional Islands
Printer/Scanner Option
Image HDD15 Pinout
Example WIN.INI
Displayable Modes
Installing Data Files
Using Non-Standard Displays
Display ID Numbers
Monitors Supported (DISPFILE.0xx)
ADF Sections

Image Adapter/A


J1-3 44-pin sockets
J4 28-pin socket
J5 15-pin video plug
J6 Printer/scanner plug
U2-9 MT4C4256-8 or TMS44C256-12
U10-17 NEC D42274V-10 VRAM
U18-25 Sockets for ZIPP VRAM
U26-29 TI TMS44C256-12N
U31 188666 IBM 53 DSS
U33 51F1819 Palette / DAC
U43 1888641
U44 45F3367 IBM (BIOS)
U54 4.0000 MHz Osc
PB Bracket for U18-25 (44F9949)

DRAM Expansion 256Kx4 Fast Page DRAM, 120 ns

TMS44C256-12N Enhanced page mode operation with CAS [-] before RAS [-] refresh
KM44C256AP-10 [-nP is DIP version]

U43 -MIGHT- be a Hitachi HD63484 Advanced CRT Controller (ACRTC) datasheet
HD63484 ACRTC Advanced CRT Controller User's Manual

U10-13 / U14-17 Base 1MB VRAM Display Memory
U18-21 / U22-25 Optional 1MB VRAM Display Memory
U2-9 Optional 1MB DRAM [Work Area]
U26-29 512KB Instruction DRAM

U31 188666 / RISC Video and I/O Processor (Display Controller and Processor (DCP) )
   Cotswold II ?

U33 Serializer / Palette / DAC  [SPD]
U43 Display Support Chip   [DS]

Differences Between 07Fnnnn and 06G822n
The '90 07F2511 is littered with decoupling caps... It has a 4.0 MHz crystal above U33, and a 4.0 MHz osc to the lower left of J1. U33 is 9019 and U31 is 9034. BIOS is 17/10/90. All logic is through-hole but all memory is through-hole DIPs or socketed DIPs/ZIPs.

The '92 06G8224 [35G4719] only has a 4.00000 MHz osc above U33 and NO XTAL. The glut of decoupling caps are gone, much smaller SMD logic chips have replaced more than a third of the logic, but all memory is still through-hole DIPs or socketed DIPs/ZIPs. U33 is 9226 and U31 is 9223. BIOS is 15/06/92.

The 07Fnnnn versions will positively blow chunks with an M complex. The 06G8224 will work with the M complex...

Huh, I see a 35G4715 / 06G8224, with a DSC of 9106, yet I see other 06G822x with chip dates of '92... Can't prove it, but this makes sense if the 8221, 8222, and 8223 are the same board but with / without options disk. I wonder if 8224 has the 1.04 options disk...

Installation of IBM PS/2 IA/A in 32-bit system slots is restricted to those without matched memory extension.

DSC Date Code

While comparing the 07 and 06 variants of the Image /A, I was stumped on deciphering the date code of the DSC, U43.

188641 IBM Chip P/N
IBM 53 IBM Fab
02000043100 Date
05 25 Dunno

Look at the eleven digit code on the third line. The first digit is the year digit starting in 1990. The second and third digits are the week.

So, "020" Means 1990, week 20.

Image /A Block Diagram

The Display Support Chip A small gate-array VLSI chip providing synchronization and timing pulse generation for the display and Image Adapter card.

Image Adapter/A DCP and DSC Functional Islands

Image /A Display Processor Block  

Image/A Serializer / Palette / DAC Block  [SPD]

The Serializer/Palette/DAC circuit types integrated on a single chip:
1. High speed static RAM (8 ns access)
2. Logic (6000 cells)
3. Digital-to-Analogue convertors, custom designed
4. Phase-Locked-Loop and Voltage-Controlled-Oscillators

The SPD chip provides all the function of the INMOS GI71 component used on PS/2 planars and in the IBM 8514/A display adapter.

However, the SPD has improved flexibility and function over the IBM VGA and 8514A:
INMOS G171 compatible palette & DAC
Colour comparators for diagnostic verification of DAC outputs
32 bit to 8 bit serializer
Cost-reduced DAC current and comparator voltage reference sources
Clocks and dividers for PS/2 monitors of 25.175, 28.321, & 44.90 MHz.

Additional function and flexibility is provided:
256 by 24 palette with 8 bit DACs
Support for a video data word width of 8, 16 and 32 bits formatted as 1 , 2, 4, 8 and 16 bpp.
Generation of video logic and shift clocks for the CRTC and video RAMS
Differential current outputs.

From what little I see, 16bpp is "palette bypass" [Direct Color] like the original XGA.

Image Adapter/A Versions 

 1. Image Adapter/A 1MB - 1MB VRAM.
 2. Image Adapter/A 3MB - 2MB VRAM and 1MB DRAM.
 3. Image Adapter/A 3MB 6091 - Image Adapter/A 3MB with cable for IBM 6091 - 019.

Note: There is no 2MB version of the Image Adapter/A.
            2MB VRAM / 0MB DRAM  - OR -  1MB VRAM / 1MB DRAM?

Downlevel: Same PCB, different memory amounts
                      P/N 07F4401, 07F2481,  07F2508

     P/N 07F4401 - Replaced by P/N07F2508
     P/N 07F2481 - Replaced by P/N06G8224 + P/N75X5894 (8 VRAMS)
     P/N 07F2508 - Replaced by P/N06G8221

Current: Same PCB, different memory amounts
      P/N 06G8224   Image Adapter/A 1MB     CURRENT LEVEL
      P/N 06G8221 - Same as P/N 06G8223 w/o  Image Adapter/A Ver 1.03 Option Disk.
      P/N 06G8221 - Replaced by 06G8223
      P/N 06G8223 - Replaced by 06G8224 (CONTAINS 1.03 Option Disk)

           1 MByte FRU ==> 06G8221
           3 MByte FRU ==> 06G8222

8590/95 "M" System Hang with Image Adapter/A installed  H101665

    A CP 40 (Stage 1 Video Test) POST Hang Condition Will Happen on an 8590 / 8595 0MF or 0MT (50MHZ complex) if an early version Image Adapter/A is installed.

8590 / 8590 "M" class systems must have Image Adapter/A FRU P/N 06G8224 (MKTing Option 35G4712, 35G4713, or 35G4714). The Following Image Adapter/A will not work in the 50 MHZ 8590 and 8595 FRU P/N 06G8221, 06G8223, 07F2481 and 07F2508

Printer/Scanner Daughtercard FRU 07F4403 (From William Walsh HERE)

Image/A Scanner-Printer Daughtercard

J1-4 Header to Image Adapter/A
U14 75X8841
U29 Zilog Z85C3010PSC
U30 10.00 MHz Osc
U31 37F9937

Z85C3010PSC CMOS SCC (serial communications controller) 10MHz Datasheet
85C30 Optimized for non-Multiplexed Bus Microprocessors

Using Image Adapter/A with 4216-020 Personal Page Printer
>FWIW, I was told once by a Lexmark rep that you could also talk to this printer through a port on the Image Adapter/A card. I never had an IA/A myself, so I'm not sure if this meant all IA/A's or a certain version or possibly a special daughtercard.

1. This is only applicable for the "Image Adapter /A" - not the Image-I-Adapter.

2. You need the "Printer / Scanner Feature Card" FRU 07F4403 and the "Printer / Scanner Y-Cable" FRU 07F4417. Probably the "Memory Module DRAM" (Kit) 07F44407.

The Y-cable connects to the IBM 3117 Scanner on the one side and to the 4216-020 "Raw Engine" on the other port. However: the driver support was rather poor (Win 3.0 / 3.1 and OS/2 up to 2.0 only IIRC). Have seen this combo at a customer once (back in 1991 or so) but never worked with it nor serviced it.

Peter in Germany

Image Adapter/A Part Numbers

1-MB MKT P/N 35G4715
3-MB MKT P/N 35G4716
3-MB + 6091-Cable MKT P/N 35G4717
9527 Cable MKT P/N 95G9906
9521 Cable MKT P/N 95G9907

The Image Adapter/A is capable of driving displays up to 128 MHz, with a maximum resolution of 1600x1200 pels. The Driver output impedance for video signals is 75 ohms. The sync lines of the adapter are TTL levels driven by 4ma drivers, so termination should be at 750 ohms (minimum)

It contains a 32 bit 8.5 MIP display processor, a 128 MHz serializer, video palette, digital to analog converters and a CRT controller.

Memory consists of 1MB VRAM (U10-17), optional 1MB of VRAM (U18-25),  512KB of instruction RAM (U26-29) and 1MB DRAM Memory Expansion (U2-9). 

Printer/Scanner Option (#1632) is available allowing direct attachment of :
o   IBM 3812 Printer Model 002 with Image Feature (#4050)
o   IBM 4216 Personal Pageprinter Model 020
o   IBM 3117 Scanner with extension unit (PN 6456808)
o   IBM 3118 Scanner or Bell & Howell 2115I (1) Scanner or equivalent
       IBM PS/2 Image Adapter/A enables both a scanner and a printer to be attached at one time via this optional printer/scanner daughter card. Use of the Printer/Scanner Option does not require an extra system unit slot.

Image Adapter/A Memory Configurations

1MB 8x 0x 0x
2MB 8x 0x 8x
3MB 8x 8x 8x
3MB 6091 8x 8x 8x
*Includes cable for IBM 6019-019 Color Display

Image Adapter/A Memory Modules:

07F4407    1      DRAM        128K EACH (8x needed)
75X5894 *  1      VRAM        128K EACH (8x needed)

75X5894 used in XGA Adapter/A, Model 90 planar XGA, and Image Adapter/A.

      The three versions of the Image Adapter/A support IBM analog displays equipped with a 15-pin direct-drive analog interface

There seems to be three incompatible systems, the 8557SX (DMA?), the 8573-P70 (video slot steals a line for dimming the plasma), and the 8570-A21 (unknown if 486 based -Bxx also affected).

 6019-019 Display Cable
   This cable is included with the Image Adapter/A 3MB 6019. The cable must be ordered separately for all others 

Image Adapter/A Options 
 You can attach optional features only to the Image Adapter/A
   1. Printer/Scanner Option
   2. Memory Expansion Kit
   3. PS/2 Video Memory Expansion Option 
  For a single display configuration, you must always attach the display to the display connector on the Image Adapter/A and not to the system- unit display connector.

Image Adapter/A 15-pin Analog Video Connector

Pin Color Mode Mono Mode
1 Red Video Reserved
2 Green Video Video
3 Blue Video Reserved
4 Display ID 2 Display ID 2
5 Self-Test Self-Test
6 Red Ground Reserved
7 Green Ground Video Ground
8 Blue Ground Reserved
9 +12 V (fused) +12 V (fused)
10 Digital Ground Digital Ground
11 Display ID 0 Display ID 0
12 Display ID 1 Display ID 1
13 External Hsync External Hsync
14 External Vsync External Vsync
15 Display ID 3 Display ID 3

Example WIN.INI

An example set of options in the WIN.INI file looks like:

[Image Adapter/A]
Resolution=1024 768

Version Version of Image Adapter/A Win3.1 Display Driver . 

Resolution X and Y dimensions (in pixels) of the display mode required. See HERE for a list of valid modes. If an invalid mode is specified, the driver reverts to its default (the highest resolution available on the display attached). 

BitsPerPixel Specified as 1, 2, 4, 8 or 16. Note that some of the higher bits per pixel are invalid in some of the Image Adapter/A memory configurations. If an invalid bits per pixel is specified, the driver reverts to its default (the highest bits per pixel available (up to 8) at the selected resolution). 

PaletteManager At 1, 2 and 4 bits per pixel, the palette is fixed to 2, 4, and 16 colors respectively. The Palette Manager options do not apply and are ignored. Dithering is enabled to approximate colors that are not in the palette.  At 16 bits per pixel, the adapter is in direct color mode and there is no palette, the Palette Manager options do not apply and are ignored. Dithering is disabled. 

Three PaletteManager options, at 8 bits per pixel 

YES     Palette Manager enabled
     At 8 bits per pixel (256 color mode) only 20 system colors are assigned (10 at the bottom and 10 at the top). The remaining 236 colors are available for the Palette Manager to assign to applications that request them. For applications that do not use the Palette Manager, dithering is enabled to approximate colors that are not in the system palette. This is the default setting at 8 bits per pixel. 

NO      Palette Manager disabled
     At 8 bits per pixel the palette is fixed to a particular set of colors. Dithering is disabled, the driver selects the nearest color available from the fixed palette. 

GRAY    Gray scale palette
     At 8 bits per pixel there are 256 shades of gray (even on a color display). In all other aspects it is like the fixed palette. This option may be useful for certain applications. This is NOT usually the best palette to select for monochrome displays, unless the application is specifically designed for gray level displays. 

If you need to switch this option on or off see "Switching the Palette Manager On and Off". 

MemoryUsage Reserved for special applications designed to run only on the Image Adapter/A. Unless you are using one of these special applications this option should always be set to Maximum. 

DualScreen Only applies when you have two displays attached to your system. For example, a VGA display attached to the standard VGA port of the system unit and a high resolution display attached to the Image Adapter/A. 

NO      The display attached to the Image Adapter/A will always be used as the main display for running Windows applications and full screen VGA applications. When running full screen VGA applications both displays will be showing the same results. This is the default setting. 

YES     During a Windows session the display attached to the Image Adapter/A will be used only for running Windows applications. When running full screen VGA applications (from within the Windows environment) only the VGA display will display the VGA application. Windows applications running in the background on the Windows display will continue to be updated. 

If you have only one display (attached to the Image Adapter/A), select NO for this option. 

StretchBlt Whether the driver registers its capability to scale images. 

YES     The display driver will register the StretchBlt capability and image scaling will be preformed by the adapter. This results in a considerable performance improvement. This is the default. 

NO      The display driver doesn't register the StretchBlt capability and the Windows graphics engine simulates the image scaling in software. 

VirtualScreen X and Y dimensions(in pixels) of the virtual display mode required. The x possible value is 1024,2048, 4096 and y possible value is 1024,2048,3072,4096. See Table 5,6,7 for a list of valid modes. Virtual screen is not supported with only 1MB card. If invalid value is specified, virtual screen is disabled. If you want to disable virtual screen, specify "VirtualScreen=No". 

Display Modes  The following tables show the display resolutions and bits per pixel available for the various display and memory configurations. The numbers represent the bits per pixel. A blank box means the resolution is not supported. There is more information, in the READ.ME of Display support diskette. Refer it for the detail. 

Displayable Modes

Monitor      Res    Maxbpp  H-Freq  V-Freq  Pix-Freq  Int
                     (bpp)  (KHz)   (Hz)     (MHz)
8503       640x480    16*   31.56   60.12    25.25    N

8514       640x480    16*   31.56   60.12    25.25    N
8515      1024x768    16*   35.60   43.58    45.00    Y

8508       640x480     8    70.79  67.04    64.00    N
          1024x768     8    72.33  85.49   103.00    N
          1360x1024    8    70.80  67.04   128.00    N
          1600x1200    4    62.01  49.33   127.00    Y

8506       864x1200    8    50.57  40.10    53.00    Y

6091-019   640x480    16*   70.75  67.00    60.00    N
          1024x768     8    70.75  67.00   120.00    N
          1280x1024    8    70.75  67.00   120.00    N

6091-019   640x480    16*   63.06  60.00    55.00    N
 (Mode 2) 1024x768     8    63.06  60.00   111.00    N
6091-023  1280x1024    8    63.06  60.00   111.00    N

8517       640x480    16*   31.56  60.12    25.25    N
          1024x768     8    56.28  70.00    77.00    N
          1280x1024    8    56.46  51.47   103.00    Y
          1360x1024    8    56.46  51.47   103.00    Y

1091-051   640x480  I  8    75.47  71.20    64.00    N
          1024x768  I  8    75.82  71.53   128.00    N
          1280x1024 I  8    75.82  71.53   128.00    N

6091-016   640x480     8    81.14  76.83    74.00    N
6091-19i  1024x768  I  8    81.14  76.83   148.00    N
          1280x1024 I  8    81.14  76.83   148.00    N

9515       640x480    16*   39.37  75.00    31.50    N
          1024x768     8    61.08  75.78    86.00    N

9518       640x480    16*   39.37  75.00    31.50    N

9517       640x480    16*   39.37  75.00    31.50    N
          1024x768     8    58.14  72.04    80.00    N
          1280x1024    8    58.11  52.97   106.00    Y
          1360x1024    8    58.11  52.97   106.00    Y

* - Windows up to 16bpp, PM/DOS/AIX supports up to 8bpp
   If there is less than 3M byte on Image Adapter/A, displayable modes and bpp may be reduced.

How to Install Display Data Files to Your System
   Image Adapter/A version 2.00 or later drivers automatically detect the attached monitor and find correct Display Data File. You can also specify the name of Display Display Data File to be used and its directory.

Each driver expects the default directory path to find Display Data File if no special path is specified. The default directories are as follows.

Windows: C:\IBMIAA
OS/2: C:\OS2\IBMIAA (C: is the boot drive here)
AIX: /usr/lpp/ibm-iaa/lpp.ddf

If you wish to specify Display Data File name, please add the option to your system CONFIG.SYS driver statement like the following example. (The case of Windows driver)


Where, 49 is decimal value of hex 31 (DISPFILE.031), and 'C' indicates this is a color monitor. If you change 'C' to 'M', driver assumes the attached monitor is a monochrome monitor which has the same timing. 

If you wish to change Display Data File directory other than default, please add the option like the following example. (The case of OS/2 driver) 


You cannot change default Display Data File path in AIX driver by this option. Please refer to readme file in each driver diskette for further information about each driver installation.

Using Non-Standard Displays

The Image Adapter/A can connect to any display that is compatible with the IBM Displays, 8503, 8506, 8507, 8508, 8512, 8513, 8514, 8515 and 6091 19". To enable other displays to operate correctly you may need to override the display ID that is returned by the display.

The display ID override is a command line option that should be placed after the DEVICE=IADOSRFS.SYS line in your CONFIG.SYS. For example to override the display ID to 8 for a color display the line would look like:


Table 9 lists the different ID's that should be used for the various possible modes. Note that you still need to specify the correct resolution in the WIN.INI file.

Display ID Numbers

Screen Color Display Mono Display
640x480 NI 1 2
1024x768 IL 5 6
1024x768 NI 21C 21M
864x1200 IL 10C 10M
1280x1024 NI 11C 11M
1360x1024 IL 21C 21M
1360x1024 NI 8C 8M
1600x1200 IL 8C 8M

Note: IL refers to interlaced and NI refers to non-interlaced.

Monitors Supported

Image Adapter/A and Image-I Adapter/A Display Support diskette 2.10.

These files are used to install version 2.00 or later level of Image Adapter/A and device drivers to your system. Each file has a information table for the following monitor.

DISPFILE.000  :     No monitor
DISPFILE.001  :     8512 8513 8518
DISPFILE.002  :     8503 8504
DISPFILE.004  :     8515 8516
DISPFILE.005  :     8514
DISPFILE.006  :     8604 8507
DISPFILE.008  :     8508
DISPFILE.00A  :     8506
DISPFILE.00B  :     6091-019
DISPFILE.20B  :     6091-019 (Mode 2 60Hz) 6091-023 5081
DISPFILE.015  :     8517
DISPFILE.018  :     1091-051
DISPFILE.019  :     6091-016
DISPFILE.01B  :     6091-19i
DISPFILE.020  :     9515
DISPFILE.021  :     9518
DISPFILE.031  :     9517
DISPFILE.080  :     9527
DISPFILE.081  :     9521
DISPFILE.08A  :     9504

Painful Probulation (from WBST)

I've been delving into the registers used by the DOS Adapter Interface device driver for these variants (IDs 8DF0-8DF5, possibly including 8DF6-8DFF from the code).

Initial comments:
   Driver chains Int 7Fh
   Support for up to 4 adapters at the same time
   Driver uses Int 15h AH=C4h, AL=00h-02h calls to query and enable adapters

Multi-Card Adapter

US5530887A Methods and apparatus for providing automatic hardware device identification in computer systems that include multi-card adapters and/or multi-card planar complexes

The Image Adapter/A is a Multi-Card Adapter:
@8DF0.ADF - IBM Image Adapter/A
@8DF1.ADF - IBM Image/A and Printer/Scanner Option
@8DF2.ADF - DSS and sub card 2
@8DF3.ADF - DSS and sub card 3
@8DF4.ADF - IBM Image Adapter/A 3MB
@8DF5.ADF - IBM Image/A with Printer/Scanner Option

AdapterID 08DF4h "IBM Image Adapter/A" (with 3MB)

DMA Arbitration Level
   DMA channel arbitration level used. The default of 5 is an arbitrary decision!
      <"Level 5">, 6, 7, 8, 9, 10, 11, 12, 13, 14, 0, 1, 2, 3, 4 

Fairness On/Off
   Whether IA/A will release control of the bus when it has been using it exclusively.
        <"On">, Off 

Adapter I/O Addressing
   Adapter I/O Addressing locations
        <"I/O Addresses 1D00 to 1D7F">, 2D00 to 2D7F, 3D00 to 3D7F, 4D00 to 4D7F 

Adapter Memory Location
   Memory location IA/A will use for the BIOS ROM, and RAM window
       <"Segment C000"> (C000-C1FF), C200 (C200-C3FF), C400 (C400-C5FF), C600 (C600-C7FF), C800 (C800-C9FF), CA00 (CA00-CBFF), CC00 (CC00-CDFF), CE00 (CE00-CFFF), D000 (D000-D1FF), D200 (D200-D3FF), D400 (D400-D5FF), D600 (D600-D7FF), D800 (D800-D9FF), DA00 (DA00-DBFF), DC00 (DC00-DDFF), DE00 (DE00-DFFF) 

Extended Memory Window
   Some apps may require an Extended Memory Window into IA/A RAM to appear high in system address space.
       <"Disabled">, "1 Meg at Address E00000" (e000-eFFF), D00000 (d000-dFFF), C00000 (c000-cFFF), B00000 (b000-bFFF), A0000 (a000-aFFF), 900000 (9000-9FFF), 800000, 8000-8FFF), 700000 (7000-7FFF), 600000 (6000-6FFF), 500000 (5000-5FFF), 400000 (4000-4FFF), 300000 (3000-3FFF), 200000 (2000-2FFF), 100000 (1000-1FFF)
       "2 Meg at Address D00000" (d000-eFFF), C00000 (c000-dFFF), B00000 (b000-cFFF), A00000 (a000-bFFF), 900000 (9000-aFFF), 800000 (8000-9FFF), 700000 (7000-8FFF), 600000 (6000h-7FFF), 500000 (5000-6FFF), 400000 (4000-05FFF), 300000 (3000-4FFF), 200000 (2000-3FFF), 100000 (1000-2FFF)

Note: WBST cautions: Extended Memory window can only be enabled if, at most <=14MB is installed in the system. A slightly important caveat. This becomes a concern in later systems.

Interrupt Level
   The Interrupt level is fixed at 2
       < "Interrupt 2">

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