VGA Adapter /A

@EFFD.ADF "IBM VGA Adapter" (file date of 1988-11-04, size 102 bytes.)
   On the T0, T1, T2, and T3 refdisk. But it is not present on the T4 refdisk.

VGA Adapter /A
Compatibility and Purpose
ADF Sections


VGA Adapter /A P/N 33F4473, FRU 15F7932, FCC ID ANO6451011 [P] [P] [P] [P]

J1 VGA connector (HD-15)
OS1 25.1750 MHz Osc
OS2 28.3220 MHz Osc
U1,6,7,10,12,14,15,18 NEC D41464L-10
U2 PE-21903 35ns delay line
U5 INMOS IMSG171-35 RAMDAC
U11 15F6864 VGA controller

U1,6,7,10,12,14,15,18 NEC D41464L-10 64Kx4 DRAM, 256 KB total. Looks similar to the 8580 VGA memory.


Compatibility and Purpose

The strange thing about this adapter is the fact that it's a standard VGA (normally used as a base video) but at the same time it has the AVE MCA extension, that was designed for adapters that improve system's video capabilities in one way or another.

Notice the elongated 16-bit section of the edge connector. Its presence will prevent the adapter from being inserted into any 16-bit MCA slot. The AVE extension then prohibits insertion into 32-bit MME and BVE slots, leaving the 32-bit AVE slot as the only compatible slot type!

Intended use currently unknown. Searching ALETs, RETAIN tips, and other documents gives no hits. Looking at possible systems shows no VGA Adapter /A. Yet here it is.


AdapterID 0effdh "IBM VGA Adapter" Sections

AdapterName "IBM VGA Adapter"
Numbytes 1
fixedresources pos[0]=0000000xb

And that is it. The ADF does not fill me up with confidence. I see no EPROM or Flash on the card, so my SWAG is this card sits on standard VGA addresses. pos[0] bit 0 is the CEN signal.

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

Ardent Tool of Capitalism - MAD Edition! is maintained by Tomáš Slavotínek.
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