28 Feb
2013
28 Feb
'13
9:48 a.m.
On Thu, 28 Feb 2013, Christopher Satterfield wrote:
I believe your VGA problem has to do with the older
IBM ROMs, I believe you
need the '82 BIOS to use a VGA card or any card with it's own BIOS, and
being as I have a 16-64 KB 5150 with the newer BIOS I assume yours will
work also, saying you have an EPROM programmer.
Be aware, however that the IBM ROMs are not pinout compatible with
2764 (although SUPER 5160 clone was). You would need to modify or
make an adapter. I've heard that there existed an EPROM that WAS
pinout compatible, but it wasn't easily available 30 years ago when
I needed one. (actually 5, since I wanted to include the BASIC)
There are some great, albeit possibly apocryphal, anecdotes
regarding the SIXTH ROM socket. (present on IBM 5150)
One story is that IBM asked Microsoft the size for the BASIC.
Microsoft said "32K".
IBM expected the size to "go over budget", and socketed for a spare 8K.
Microsoft was offended, and made sure, including some padding, that the
release version of the BIOS used EXACTLY 32768 bytes.
Anybody remember USES of the SIXTH ROM socket?
"MBI" (probably a different MBI) made a supplement ROM that added
some printer configuration features, etc.
I think that there still is one in my 16K 5150
Other "non-standard" ROMs:
Todd Fischer? made a diagnostics ROM, to temporarily replace the BIOS ROM,
and communicate through the serial port!
--
Grumpy Ol' Fred cisin at xenosoft.com