

>>>>>>>>  TEST5055


------------------------------------
TARGET
------------------------------------

This is code to go into ROM U33 on an IBM 5150 (IBM PC) motherboard.
The IBM 5150 has special ROM requirements. See http://www.minuszerodegrees.net/5150/motherboard/5150_u33.htm


------------------------------------
REQUIRED
------------------------------------

1. A parallel (LPT) port POST code reader.
   See http://www.minuszerodegrees.net/images4/Parallel%20port%20monitoring%20POST%20board.jpg

2. A parallel (LPT) port on your computer that is at one of the following I/O addresses: 378 or 278 or 3BC

3. A way of putting the BIN file into a suitable ROM/EPROM/EEPROM.
   The IBM 5150 has special ROM requirements. See http://www.minuszerodegrees.net/5150/motherboard/5150_u33.htm


------------------------------------
BIN FILES
------------------------------------

Per http://www.minuszerodegrees.net/5150/motherboard/5150_u33.htm, if a suitable adapter is used, 16 KB and 32 KB sized ROM/EPROM's can be used on the IBM 5150 motherboard.
Because of that, included here are 16 KB and 32 KB versions of TEST5055_8KB_SIZED.BIN, being TEST5055_16KB_SIZED.BIN and TEST5055_32KB_SIZED.BIN

TEST5055_8KB_SIZED.BIN is for an MCM68766 EPROM, or a 2564 EPROM.
TEST5055_16KB_SIZED.BIN is for a 27C128 EPROM (in a suitable adapter).
TEST5055_32KB_SIZED.BIN is for a 27C256 EPROM (in a suitable adapter) or W27E257 EEPROM (in a suitable adapter).

Again, see http://www.minuszerodegrees.net/5150/motherboard/5150_u33.htm


------------------------------------
WHAT DOES THE CODE DO ?
------------------------------------

All that the code does is send the byte of {55} to LPT ports 378, 278, and 3BC, then it halts the CPU.


------------------------------------
WHAT YOU SHOULD OBSERVE
------------------------------------

The last (repeat: last) code/byte seen on your parallel port code reader should be {55}.

