• |
Program is not being run on a PC or XT class computer. |
|
|
• |
Warn-then-exit if the motherboard BIOS (if identified) is known not to support BIOS expansion ROM's. (Usually, 1981 and 1982 dated motherboard BIOS'.) |
|
|
• |
Warn-then-exit if unable to find a BIOS expansion ROM starting at address C8000. |
|
|
• |
Warn-then-exit if the declared size (third byte of BIOS expansion ROM) is zero. |
• |
Warn-then-exit if the declared size (third byte of BIOS expansion ROM) is not a multiple of 2 KB. |
• |
Warn-then-exit if the declared size (third byte of BIOS expansion ROM) is greater than 32 KB. |
• |
Warn (but do not exit) if the declared size (third byte of BIOS expansion ROM) is less than 4 KB. (Very suspicious.) |
|
|
• |
Warn (but do not exit) if the 8-bit checksum of the declared size is not 00. |
|
(A warning at this stage because of what I have seen with some controllers.) |
|
|
• |
Warn-then-exit if the BIOS expansion ROM found at C8000 has been identified as being for a SCSI card. |
|
|
• |
Warn-then-exit if the BIOS expansion ROM found at C8000 has been identified as being the XTIDE Universal BIOS (XUB). |
|
|
• |
Warn-then-exit if the BIOS expansion ROM found at C8000 cannot be identified.
(Only if the BIOS is identified as being one for an XT-class MFM/RLL type hard drive controller, are later test/checks valid.) |
|
|
• |
If an IBM 5150/5160 BIOS, warn-then-exit if the vector for software interrupt 0Dh (i.e. triggered by hardware IRQ5) has not been changed from the one set by the power-on self test.
(That would indicate that the initialisation code in the controller's BIOS ROM has not been executed.) |