EduQuest Fifty-Five

Type 9615

194-164 IBM Educational Computer, IBM EduQuest Fifty-Five

EduQuest Fifty-Five Photo

eduq_05g.exe Flash BIOS update, revision 05G (self-extracting). EduQuest Fifty-Five specific files (from Andrew Lawton) EduQuest "Schoolbox"

Planar Outline
Switch Block (SW1)
VRAM Sockets & Video Capabilities
Flash BIOS Update
Other Supporting Files
EduQuest "Schoolbox"

Based on content by William R. Walsh (original HERE). Edited by Major Tom.


Offered processor options:
486 SX 33, 486 SX2 25/50, 486 DX 33, 486 DX2 25/50, 486DX2-33/66, 486 DX4 33/100


Battery CR2032 CMOS battery
JP1 Power On Password Clear
JP2 see below
SW1 switch block
U8,9 2x512K VRAM
U11,15 VRAM Upgrade Socket
U12 Intel Flash Chip (BIOS update)
U16 VLSI VL82C114
U17 SMSC FDC37C65 (no 2.88 supp.)
U19 Cirrus Logic 5434 Video
U23 VLSI VL82C003
U26 Socket 3 (ZIF)
U27 Linear Tech LT1085 reg.
U38-53 Cache Sockets (U38 TAG?)
U54 VL82C483


JP2 1-2 (pin one is pads only) Boot Block Program, 2-3 Normal Operation (this may have to do with flash BIOS recovery support)

U13 Marked as U13 ROM BIOS (could be used for bad flash recovery, this machine supports it)

Big Solder Pads are in an arrangement that looks like there may have been plans for a VL-bus version of this EduQuest.

Looks to me like this is a vastly revised planar as compared to the EduQuest 30 and 40 where lots of the design stayed the same with only minor changes. You really can't compare this planar to the 30 and 40 models.

Missing from this board are a lot of what I consider to have been "vestigial features" on the 30 and 40 such as the ever present but always empty "Mask ROM" socket.

Looking at U27 (an LT1085 regulator commonly used for such things) and seeing no manual voltage switch I am inclined to believe that this board can automatically detect the voltage requirements of the CPU in use. There is a jumper not shown above that would let one select between 3.3 and 3.45 volts, but it is not populated (solder pads only) so that may be automatic as well.

I'm not sure what the maximum amount of RAM this system can handle is. I wouldn't be surprised if it took 64MB. It appears to be standard non-parity stuff.

Switch Block (SW1)

EQ55 SW1 Settings

Switches are "ON" when upwards.

SX - Selects an i486SX or 'other' CPU
25 - Selects between 25 and 33MHz base clock speeds
WT - L1 Cache Operation Mode WT = Write-Thru or L1-WB = Level 1 Write Back
(Note: Write Back improves performance drastically but may not be 100% compatible with certain processors and might increase the risk of data corruption on system failure.)
PDIS - Unknown (Perhaps it enables or disables parity? For what is unknown...)

VRAM Sockets & Video Capabilities

I popped in two upgrade VRAMs into each socket and powered up. I was more than a little puzzled when the machine didn't report the new VRAM, but since they were rather crudely desoldered from another dead board, I figured maybe some pin straightening might be in order. That did the trick and got the system seeing all 2MB of installed VRAM.

Video is provided by a Cirrus 5434 accelerator. With 1MB VRAM you can run up to 256 colors in 1024x768. (Oddly enough 1MB is not enough VRAM for 800x600 at high color, only 256) With all 2MB installed, you can run at least high color in all supported modes (640x480 to 1024x768).

It appears that the video BIOS has been customized for the internal monitor, and all SVGA modes run at 72Hz scan rate. You can connect an external monitor, though what would change about the video chip's behavior I don't yet know. System setup has an option to disable the internal display if you're using modes it wouldn't support.

Flash BIOS

Download the self-extracting file here. This is the genuine and original IBM file. It will take your EduQuest system from revision 00G to 05G.

Extraction may need to be done under pure DOS and not Windows NT, as when run on an NT system, no keyboard input to the program was possible.

Warning: Though most BIOS flash operations go as planned, errors are possible due to power failures, problems with the flash source and other little things that can go wrong. While I don't want to discourage you from applying this update if you need it, I don't advise applying it just because it is here and you can. Please make sure that your machine is in fact an EduQuest Model 55 and make the flash "undo diskette" prior to updating.

This update is provided on a "use at your own risk" basis. YOU are responsible for the results of using it, whether good or bad.

This flash update supposedly fixes floppy drive read and write errors.

Other Supporting Files

Andrew Lawton supplied an archive containing several EduQuest Model 55 specific files, including the previously mentioned flash BIOS update. You can download them here. I have not personally used or tested them and I have no idea what they are intended for. As such, and as always, you use them at your own risk.

EduQuest "Schoolbox"

School Box is described as some sort of driver and diagnostic package. So, naturally, the same disclaimer you've heard several times by now applies. Strongly. But if you still have an EduQuest 55, you might find it useful. Click here to download it. (Originally uploaded in this thread of discussion. Posted here in the name of preservation and because — rather amazingly — a link that was posted five years ago and labeled as "temporary" still worked. Sometimes you just get lucky.)

Ed. Tom: Info sourced from IBM announcement documents:

EduQuest Schoolbox: The EduQuest Schoolbox is not included with each system since one Schoolbox can be shared among several system units.

The EduQuest Schoolbox consists of a package of items to complement the basic system unit. It provides a single common source for software and documentation that are not ordinarily required with each system for typical standard usage. It provides a single repository of support function items that may be needed for advanced or specialized situations.

The EduQuest Schoolbox includes:

  • System utilities
  • DOS, Windows, and OS/2(R) audio drivers
  • DOS, Windows, and OS/2 display drivers
  • User Guide

To install some options, you need support available in the EduQuest Schoolbox. An example is when you want to change video modes or add one of the EduQuest LAN adapters. You need to ensure that the code and programs in the EduQuest Schoolbox are available when needed. The Schoolbox is a separately ordered feature and not included with the basic system unit. It is strongly recommended that you order one Schoolbox with the initial system. Order additional copies of the Schoolbox, as desired, to share with multiple systems.

Content created and/or collected by:
Louis F. Ohland, Peter H. Wendt, David L. Beem, William R. Walsh, Tatsuo Sunagawa, Tomáš Slavotínek, Jim Shorney, Tim N. Clarke, Kevin Bowling, and many others.

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